WO2015099038A1

WO2015099038A1 - Optical system, optical device, and manufacturing method for optical system

Info

Publication number: WO2015099038A1
Application number: PCT/JP2014/084308
Authority: WO
Inventors: 哲史三輪; 俊典武; 一政田中
Original assignee: 株式会社ニコン
Priority date: 2013-12-26
Filing date: 2014-12-25
Publication date: 2015-07-02

Abstract

In the present invention, the following are provided in order from the object side: a first lens group (G1) having a positive refractive power; a second lens group (G2) having a negative refractive power; and a third lens group having a positive refractive power. Focusing from an infinite object to a near object is carried out by causing the second lens group (G2) to move along the light axis, and a prescribed conditional formula is satisfied. Due to this configuration, provided are the following: an optical system that is small and has favorable optical characteristics; an optical device; and a manufacturing method for the optical system.

Description

OPTICAL SYSTEM, OPTICAL DEVICE, AND OPTICAL SYSTEM MANUFACTURING METHOD

The present invention relates to an optical system, an optical apparatus, and an optical system manufacturing method.

Conventionally, in photo cameras and electronic still cameras, telephoto type inner focus optical systems are often used as optical systems having a large focal length. For example, see Japanese Patent Application Laid-Open No. 2008-164997.

JP 2008-164997 A

However, the conventional optical system as described above has a problem that the performance is not sufficiently improved.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide an optical system, an optical device, and a method for manufacturing the optical system having good optical performance.

In order to solve the above problems, the first aspect of the present invention is:
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
By moving the second lens group along the optical axis, focusing from an object at infinity to an object at a short distance,
An optical system characterized by satisfying the following conditional expression is provided.
0.10 <f / f12 <0.55
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

The second aspect of the present invention is
An optical apparatus having the optical system according to the first aspect of the present invention is provided.

The third aspect of the present invention is:
A method of manufacturing an optical system having, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. ,
The optical system satisfies the following conditional expression,
An optical system manufacturing method is provided in which focusing from an object at infinity to an object at a short distance is performed by moving the second lens group along an optical axis.
0.10 <f / f12 <0.55
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

The fourth aspect of the present invention is
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
By moving the second lens group along the optical axis, focusing from an object at infinity to an object at a short distance,
The second lens group has at least three lenses;
An optical system characterized by satisfying the following conditional expression is provided.
0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

The fifth aspect of the present invention is
An optical apparatus comprising the optical system according to the fourth aspect of the present invention is provided.

The sixth aspect of the present invention is
A method of manufacturing an optical system having, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. ,
The second lens group includes at least three lenses;
The optical system satisfies the following conditional expression,
An optical system manufacturing method is provided in which focusing from an object at infinity to an object at a short distance is performed by moving the second lens group along an optical axis.
0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

The seventh aspect of the present invention is
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
When focusing from an object at infinity to a near object, the second lens group moves along the optical axis;
A part of the third lens group moves as a shift lens group so as to include a component in a direction orthogonal to the optical axis;
An optical system characterized by satisfying the following conditional expression is provided.
−1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

The eighth aspect of the present invention provides
An optical apparatus having the optical system according to the seventh aspect of the present invention is provided.

The ninth aspect of the present invention
A method of manufacturing an optical system having, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. ,
The second lens group moves along the optical axis when focusing from an object at infinity to an object at a short distance;
A part of the third lens group moves as a shift lens group so as to include a component in a direction orthogonal to the optical axis;
Provided is a method for manufacturing an optical system, characterized in that the optical system satisfies the following conditional expression.
−1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

The tenth aspect of the present invention provides
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
The third lens group includes, in order from the object side, a 3a lens group and a 3b lens group,
When focusing from an object at infinity to a near object, the second lens group moves along the optical axis;
The third lens group moves as a shift lens group so as to include a component in a direction perpendicular to the optical axis,
An optical system characterized by satisfying the following conditional expression is provided.
1.70 <| fR / fF | <5.00
However,
fF: Composite focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: Nearer to the image side than the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Combined focal length of all lenses located

The eleventh aspect of the present invention provides
An optical apparatus having the optical system according to the tenth aspect of the present invention is provided.

The twelfth aspect of the present invention provides
A method of manufacturing an optical system having, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. ,
The third lens group has a 3a lens group and a 3b lens group in order from the object side,
The second lens group moves along the optical axis when focusing from an object at infinity to an object at a short distance;
The third lens group is moved so as to include a component in a direction orthogonal to the optical axis as a shift lens group,
Provided is a method for manufacturing an optical system, characterized in that the optical system satisfies the following conditional expression.
1.70 <| fR / fF | <5.00
However,
fF: Composite focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: Nearer to the image side than the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Combined focal length of all lenses located

According to the first to third aspects of the present invention, it is possible to provide an optical system, an optical device, and a method for manufacturing the optical system that are small and have good optical performance.

According to the fourth to sixth aspects of the present invention, it is possible to provide an optical system, an optical device, and a method for manufacturing the optical system that are small and have good optical performance.

According to the seventh to ninth aspects of the present invention, it is possible to provide an optical system, an optical apparatus, and a method for manufacturing the optical system that correct various aberrations satisfactorily and suppress deterioration of optical performance during lens shift.

According to the tenth to twelfth aspects of the present invention, it is possible to provide an optical system, an optical apparatus, and an optical system manufacturing method that are small in size, correct various aberrations, and have excellent optical performance.

FIG. 1 is a sectional view showing a lens arrangement at the time of focusing on an object at infinity in an optical system according to a first example common to the first to eighth embodiments of the present application. 2A and 2B are graphs showing various aberrations when the optical system according to the first example of the present application is focused on an object at infinity and focused on a short distance object, respectively. FIG. 3 is a coma aberration diagram when the lens is shifted during focusing on an object at infinity of the optical system according to the first example of the present application. FIG. 4 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a second example common to the first to eighth embodiments of the present application. FIGS. 5A and 5B are graphs showing various aberrations when the optical system according to Example 2 of the present application is focused on an object at infinity and focused on a short distance object, respectively. FIG. 6 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the second example of the present application. FIG. 7 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a third example common to the first to eighth embodiments of the present application. 8A and 8B are graphs showing various aberrations when the optical system according to Example 3 of the present application is focused on an object at infinity and focused on a short distance object, respectively. FIG. 9 is a coma aberration diagram when the lens is shifted during focusing on an object at infinity of the optical system according to the third example of the present application. FIG. 10 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a fourth example common to the first to eighth embodiments of the present application. 11A and 11B are graphs showing various aberrations when the optical system according to Example 4 of the present application is focused on an object at infinity and focused on a short distance object, respectively. FIG. 12 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the fourth example of the present application. FIG. 13 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a fifth example common to the first to eighth embodiments of the present application. FIGS. 14A and 14B are graphs showing various aberrations when the optical system according to Example 5 of the present application is focused on an object at infinity and focused on a short distance object, respectively. FIG. 15 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to Example 5 of the present application. FIG. 16 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a sixth example common to the first to eighth embodiments of the present application. FIGS. 17A and 17B are graphs showing various aberrations when the optical system according to Example 6 of the present application is focused on an object at infinity and focused on a short distance object, respectively. FIG. 18 is a coma aberration diagram when the lens is shifted during focusing on an object at infinity of the optical system according to Example 6 of the present application. FIG. 19 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a seventh example common to the third to sixth embodiments of the present application. 20A and 20B are graphs showing various aberrations when the optical system according to Example 7 of the present application is focused on an object at infinity and focused on a short distance object, respectively. FIG. 21 is a coma aberration diagram when the lens shift is performed at the time of focusing on an object at infinity of the optical system according to Example 7 of the present application. FIG. 22 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to an eighth example common to the third to sixth embodiments of the present application. FIGS. 23A and 23B are graphs showing various aberrations when the optical system according to Example 8 of the present application is focused on an object at infinity and focused on a short distance object, respectively. FIG. 24 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the eighth example of the present application. FIG. 25 is a cross-sectional view showing the lens arrangement at the time of focusing on an object at infinity in the optical system according to Example 9 common to Embodiments 3 to 6 of the present application. FIGS. 26A and 26B are graphs showing various aberrations when the optical system according to Example 9 of the present application is focused on an object at infinity and focused on a short distance object, respectively. FIG. 27 is a coma aberration diagram when the lens shifts at the time of focusing on an object at infinity of the optical system according to Example 9 of the present application. FIG. 28 is a diagram showing a configuration of a camera including an optical system according to the first to eighth embodiments of the present application. FIG. 29 is a diagram showing an outline of a method of manufacturing an optical system according to the fifth embodiment of the present application. FIG. 30 shows an example of a state in which light rays incident on the optical system according to the first embodiment of the present application are reflected by the first reflecting surface and the second reflecting surface to form ghosts and flares on the image surface. FIG. FIG. 31 is an explanatory view showing an example of the layer structure of the antireflection film of the fifth to eighth embodiments of the present application. FIG. 32 is a graph showing the spectral characteristics of the antireflection films of the fifth to eighth embodiments of the present application. FIG. 33 is a graph showing the spectral characteristics of the antireflection film according to modifications of the fifth to eighth embodiments of the present application. FIG. 34 is a graph showing the incident angle dependence of the spectral characteristic of the antireflection film according to the modification of the fifth to eighth embodiments of the present application. FIG. 35 is a graph showing the spectral characteristics of the antireflection film prepared by the prior art. FIG. 36 is a graph showing the incident angle dependence of the spectral characteristics of the antireflection film prepared by the conventional technique. FIG. 37 is a diagram showing an outline of a method of manufacturing an optical system according to the sixth embodiment of the present application. FIG. 38 is a diagram showing an outline of the method of manufacturing the optical system according to the first embodiment of the present application. FIG. 39 is a diagram showing an outline of a method for manufacturing an optical system according to the second embodiment of the present application. FIG. 40 is a diagram showing an outline of the manufacturing method of the optical system according to the third embodiment of the present application. FIG. 41 is a diagram showing an outline of a method of manufacturing an optical system according to the fourth embodiment of the present application. FIG. 42 is a diagram showing an outline of the method of manufacturing the optical system according to the seventh embodiment of the present application. FIG. 43 is a diagram showing an outline of the manufacturing method of the optical system according to the eighth embodiment of the present application.

Hereinafter, the optical system, the optical device, and the method for manufacturing the optical system according to the first embodiment of the present application will be described.
The optical system according to the first embodiment of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. And focusing from an object at infinity to a near object by moving the second lens group along the optical axis, and satisfying the following conditional expression (1-1): And
(1-1) 0.10 <f / f12 <0.55
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

As described above, the optical system according to the first embodiment of the present application includes, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, and the positive refractive power. And a third lens group. With this configuration, the optical system according to the first embodiment of the present application can achieve both miniaturization and high performance while having a large focal length.

Also, as described above, the optical system according to the first embodiment of the present application performs focusing from an infinitely distant object to a close object by moving the second lens group along the optical axis. With this configuration, the second lens group can be driven by a relatively small motor unit.

Conditional expression (1-1) defines the combined refractive power of the first lens group and the second lens group. The optical system according to the first embodiment of the present application can satisfactorily correct lateral chromatic aberration by satisfying conditional expression (1-1). Further, the light emitted from the second lens group becomes convergent light. For this reason, since the second lens group can be arranged on the image side and the first lens group can be arranged on the image side accordingly, the entire length of the optical system according to the first embodiment of the present application. Can be reduced. In addition, the lateral chromatic aberration can be corrected satisfactorily.

If the corresponding value of the conditional expression (1-1) of the optical system according to the first embodiment of the present application exceeds the upper limit value, it will be difficult to correct lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-1) to 0.54. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-1) to 0.53.

On the other hand, when the corresponding value of the conditional expression (1-1) of the optical system according to the first embodiment of the present application is lower than the lower limit value, the light emitted from the second lens group becomes parallel light. The overall length of the optical system according to the embodiment is increased. Therefore, if it is attempted to shorten the overall length of the optical system according to the first embodiment of the present application, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-1) to 0.20. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-1) to 0.30.
With the above configuration, an optical system having a small size and good optical performance can be realized.

In the optical system according to the first embodiment of the present application, it is desirable that the first lens group has at least one positive lens that satisfies the following conditional expression (1-2).
(1-2) 80 <νd1p <110
However,
νd1p: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the first lens group

Conditional expression (1-2) defines the Abbe number of the glass material of the positive lens in the first lens group. The optical system according to the first embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (1-2).

If the corresponding value of the conditional expression (1-2) of the optical system according to the first embodiment of the present application exceeds the upper limit value, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-2) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-2) to 100.

On the other hand, if the corresponding value of the conditional expression (1-2) of the optical system according to the first embodiment of the present application is less than the lower limit value, it is difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-2) to 85. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-2) to 90.

Further, in the optical system according to the first embodiment of the present application, the first lens group includes a plurality of positive lenses, and the positive lens arranged closest to the object among the plurality of positive lenses is the following conditional expression: It is desirable to satisfy (1-3).
(1-3) 80 <νd1pf <110
However,
νd1pf: Abbe number with respect to the d-line (wavelength 587.6 nm) of the glass material of the positive lens arranged closest to the object side among the plurality of positive lenses in the first lens group

Conditional expression (1-3) defines the Abbe number of the glass material of the positive lens arranged closest to the object among the plurality of positive lenses in the first lens group. The optical system according to the first embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (1-3).

If the corresponding value of the conditional expression (1-3) of the optical system according to the first embodiment of the present application exceeds the upper limit value, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-3) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-3) to 100.

On the other hand, if the corresponding value of the conditional expression (1-3) of the optical system according to the first embodiment of the present application is below the lower limit value, it will be difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-3) to 85. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-3) to 90.

In the optical system according to the first embodiment of the present application, it is preferable that the first lens group includes at least one negative lens that satisfies the following conditional expression (1-4).
(1-4) 1.50 <nd1n <1.75
However,
nd1n: refractive index with respect to d-line (wavelength 587.6 nm) of the glass material of the negative lens in the first lens group

Conditional expression (1-4) defines the refractive index of the glass material of the negative lens in the first lens group. The optical system according to the first embodiment of the present application can satisfactorily correct coma and curvature of field while reducing the weight by satisfying conditional expression (1-4).

When the corresponding value of the conditional expression (1-4) of the optical system according to the first embodiment of the present application exceeds the upper limit value, the specific gravity of the glass material of the negative lens in the first lens group increases. Therefore, if the specific gravity of other lenses in the first lens group is reduced in order to reduce the weight of the optical system according to the first embodiment of the present application, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-4) to 1.70. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-4) to 1.65.

On the other hand, if the corresponding value of the conditional expression (1-4) of the optical system according to the first embodiment of the present application is less than the lower limit value, it becomes difficult to correct the curvature of field. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-4) to 1.55. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-4) to 1.60.

In addition, it is desirable that the optical system according to the first embodiment of the present application moves so that at least a part of the third lens group includes a component in a direction orthogonal to the optical axis. With this configuration, image blur due to camera shake or the like can be corrected, that is, image stabilization can be performed, and the occurrence of decentration aberrations during image stabilization can be suppressed to a level where there is no problem.

In the optical system according to the first embodiment of the present application, the third lens group includes, in order from the object side, a 3a lens group having a positive refractive power, a 3b lens group having a negative refractive power, It is desirable that the third lens unit is composed of a third lens unit having positive refractive power, and the third lens unit moves so as to include a component in a direction orthogonal to the optical axis. With this configuration, image blur due to camera shake or the like can be corrected, that is, image stabilization can be performed, and the occurrence of decentration aberrations during image stabilization can be suppressed to a level where there is no problem. In addition, since the diameter of the 3b lens group can be reduced, the mechanical unit for driving the 3b lens group during vibration isolation can be reduced in size.

In the optical system according to the first embodiment of the present application, it is preferable that the first lens group includes a cemented lens of a negative lens and a positive lens in order from the object side. With this configuration, the decentration aberration can be corrected satisfactorily. The cemented lens is more preferably arranged on the most image side in the first lens group.

In the optical system according to the first embodiment of the present application, the first lens group includes a 1a lens group and a 1b lens group in order from the object side, and the 1a lens group and the 1b lens It is desirable that the air gap with the lens group is the largest of the air gaps in the first lens group, and the following conditional expression (1-5) is satisfied.
(1-5) 0.30 <TL1a / TL1 <0.70
However,
TL1a: length along the optical axis of the first lens group TL1: length along the optical axis of the first lens group

Conditional expression (1-5) defines the length of the first lens group with respect to the length of the first lens group. The optical system according to the first embodiment of the present application can satisfactorily correct the coma aberration while reducing the weight by satisfying conditional expression (1-5).

When the corresponding value of the conditional expression (1-5) of the optical system according to the first embodiment of the present application exceeds the upper limit value, the weight of the first lens group increases. Therefore, for example, if a glass material having a small refractive index is used for the negative lens in the first lens group in order to reduce the weight, it becomes difficult to correct curvature of field. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-5) to 0.60. In order to further secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-5) to 0.50.

On the other hand, when the corresponding value of the conditional expression (1-5) of the optical system according to the first embodiment of the present application is less than the lower limit value, it becomes difficult to correct the coma aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-5) to 0.35. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-5) to 0.40.

In the optical system according to the first embodiment of the present application, it is preferable that the first-a lens group includes a positive lens, a positive lens, and a negative lens in order from the object side. With this configuration, it is possible to reduce the weight of the optical system according to the first embodiment of the present application.
In the optical system according to the first embodiment of the present application, it is preferable that the first lens group has a protective filter glass on the most object side. The protective filter glass is a lens having substantially no refractive power, and the focal length thereof is preferably 10 times or more the focal length of the optical system according to the first embodiment of the present application. In particular, the optical system according to the first embodiment of the present application preferably has a negative meniscus shape in which the protective filter glass has a convex surface facing the object side. With this configuration, the ghost can be cut well.
In the optical system according to the first embodiment of the present application, it is preferable that the first-b lens group includes a negative lens and a positive lens in order from the object side. With this configuration, it is possible to satisfactorily correct variations in spherical aberration when focusing on a short-distance object. In particular, in the optical system according to the first embodiment of the present application, it is preferable that the first b lens group includes only a cemented lens of a negative lens and a positive lens in order from the object side. With this configuration, it is possible to reduce the weight of the optical system according to the first embodiment of the present application.

In the optical system according to the first embodiment of the present application, the first lens group includes a 1a lens group and a 1b lens group in order from the object side, and the 1a lens group and the 1b lens It is desirable that the air gap with the lens group is the largest of the air gaps in the first lens group, and the first b lens group has a positive lens that satisfies the following conditional expression (1-6): .
(1-6) 70 <νd1bp <110
However,
νd1bp: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the 1b lens group

Conditional expression (1-6) defines the Abbe number of the glass material of the positive lens in the 1b lens group. The optical system according to the first embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (1-6).

If the corresponding value of the conditional expression (1-6) of the optical system according to the first embodiment of the present application exceeds the upper limit value, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-6) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-6) to 100.

On the other hand, if the corresponding value of the conditional expression (1-6) of the optical system according to the first embodiment of the present application is less than the lower limit value, it is difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-6) to 75. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-6) to 80.

In the optical system according to the first embodiment of the present application, it is preferable that the second lens group has two negative lens components. With this configuration, coma can be corrected well. Here, in the present application, the “lens component” refers to a cemented lens or a single lens formed by cementing two or more lenses.
In the optical system according to the first embodiment of the present application, the second lens group may have a negative lens, a positive lens, and a negative lens in order from the object side. The second lens group may include a positive lens, a negative lens, and a negative lens in order from the object side. With these configurations, coma can be corrected well.

In the optical system according to the first embodiment of the present application, it is preferable that the second lens group includes a positive lens that satisfies the following conditional expression (1-7).
(1-7) 15 <νd2p <30
However,
νd2p: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the second lens group

Conditional expression (1-7) defines the Abbe number of the glass material of the positive lens in the second lens group. The optical system according to the first embodiment of the present application can satisfactorily correct lateral chromatic aberration and axial chromatic aberration by satisfying conditional expression (1-7).

If the corresponding value of the conditional expression (1-7) of the optical system according to the first embodiment of the present application exceeds the upper limit value, it will be difficult to correct lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (1-7) to 27. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (1-7) to 25.

On the other hand, when the corresponding value of the conditional expression (1-7) of the optical system according to the first embodiment of the present application is lower than the lower limit value, the second lens group is used to prevent the transmittance of light having a short wavelength from decreasing. However, it becomes impossible to use a lens made of a glass material having a large dispersion in the lens group located on the image side. This makes it difficult to correct axial chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (1-7) to 16. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (1-7) to 17.

The optical apparatus according to the present application includes the optical system according to the first embodiment having the above-described configuration. Thereby, an optical device having a small size and good optical performance can be realized.

The optical system manufacturing method according to the first embodiment of the present application has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. And a third lens group, wherein the optical system satisfies the following conditional expression (1-1), and the second lens group is moved along the optical axis. It is characterized in that focusing from an object at infinity to an object at a short distance is performed. Thereby, an optical system having a small size and good optical performance can be manufactured.
(1-1) 0.10 <f / f12 <0.55
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

Hereinafter, an optical system, an optical device, and an optical system manufacturing method according to the second embodiment of the present application will be described.
The optical system according to the second embodiment of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. And focusing from an object at infinity to a near object by moving the second lens group along the optical axis, and the second lens group has at least three lenses The following conditional expression (2-1) is satisfied.
(2-1) 0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

As described above, the optical system according to the second embodiment of the present application has, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, and the positive refractive power. And a third lens group. With this configuration, the optical system according to the second embodiment of the present application can achieve both miniaturization and high performance while having a large focal length.

In addition, as described above, the optical system according to the second embodiment of the present application performs focusing from an object at infinity to a near object by moving the second lens group along the optical axis. With this configuration, the second lens group can be driven by a relatively small motor unit.
As described above, in the optical system according to the second embodiment of the present application, the second lens group has at least three lenses. With this configuration, coma can be corrected well.

Conditional expression (2-1) defines the combined refractive power of the first lens group and the second lens group. The optical system according to the second embodiment of the present application can satisfactorily correct lateral chromatic aberration by satisfying conditional expression (2-1). Further, the light emitted from the second lens group becomes convergent light. For this reason, since the second lens group can be disposed more on the image side, and accordingly, the first lens group can also be disposed on the image side, the total length of the optical system according to the second embodiment of the present application. Can be reduced. In addition, the lateral chromatic aberration can be corrected satisfactorily.

If the corresponding value of conditional expression (2-1) of the optical system according to the second embodiment of the present application exceeds the upper limit value, it will be difficult to correct lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (2-1) to 0.80. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-1) to 0.75.

On the other hand, when the corresponding value of the conditional expression (2-1) of the optical system according to the second embodiment of the present application is less than the lower limit value, the light emitted from the second lens group becomes parallel light. The overall length of the optical system according to the embodiment increases. Therefore, if it is attempted to shorten the overall length of the optical system according to the second embodiment of the present application, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-1) to 0.20. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-1) to 0.30.
With the above configuration, an optical system having a small size and good optical performance can be realized.

In the optical system according to the second embodiment of the present application, it is preferable that at least two of the at least three lenses in the second lens group are negative lenses. With this configuration, coma can be corrected well.
In the optical system according to the second embodiment of the present application, the second lens group includes a negative lens, a positive lens, and a negative lens in order from the object side, or a positive lens in order from the object side. And a negative lens and a negative lens are more preferable. In these configurations, it is most preferable to join a positive lens and a negative lens. With the above configuration, coma aberration can be corrected more favorably.

In the optical system according to the second embodiment of the present application, it is preferable that the second lens group includes at least one negative lens that satisfies the following conditional expression (2-2).
(2-2) 1.45 <nd2n <1.65
However,
nd2n: refractive index with respect to d-line (wavelength 587.6 nm) of the glass material of the negative lens in the second lens group

Conditional expression (2-2) defines the refractive index of the glass material of the negative lens in the second lens group. By satisfying conditional expression (2-2), the optical system according to the second embodiment of the present application achieves good coma and curvature of field while reducing the weight of the second lens group that is the focusing lens group. Can be corrected.

When the corresponding value of the conditional expression (2-2) of the optical system according to the second embodiment of the present application exceeds the upper limit value, the specific gravity of the glass material of the negative lens in the second lens group increases. Therefore, if the specific gravity of other lenses in the second lens group is reduced in order to reduce the weight of the optical system according to the second embodiment of the present application, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-2) to 1.64. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (2-2) to 1.63.

On the other hand, if the corresponding value of the conditional expression (2-2) of the optical system according to the second embodiment of the present application is less than the lower limit value, it becomes difficult to correct the curvature of field. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-2) to 1.48. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-2) to 1.50.

In the optical system according to the second embodiment of the present application, it is preferable that the second lens group includes a positive lens that satisfies the following conditional expression (2-3).
(2-3) 15 <νd2p <30
However,
νd2p: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the second lens group

Conditional expression (2-3) defines the Abbe number of the glass material of the positive lens in the second lens group. The optical system according to the second embodiment of the present application can satisfactorily correct lateral chromatic aberration and axial chromatic aberration by satisfying conditional expression (2-3).

If the corresponding value of the conditional expression (2-3) of the optical system according to the second embodiment of the present application exceeds the upper limit value, it will be difficult to correct lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-3) to 27. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-3) to 25.

On the other hand, when the corresponding value of the conditional expression (2-3) of the optical system according to the second embodiment of the present application is less than the lower limit value, in order to prevent the transmittance of light having a short wavelength from decreasing, However, it becomes impossible to use a lens made of a glass material having a large dispersion in the lens group located on the image side. This makes it difficult to correct axial chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (2-3) to 16. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-3) to 17.

In the optical system according to the second embodiment of the present application, it is preferable that the first lens group has at least one positive lens that satisfies the following conditional expression (2-4).
(2-4) 80 <νd1p <110
However,
νd1p: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the first lens group

Conditional expression (2-4) defines the Abbe number of the glass material of the positive lens in the first lens group. The optical system according to the second embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (2-4).

If the corresponding value of the conditional expression (2-4) of the optical system according to the second embodiment of the present application exceeds the upper limit, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-4) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-4) to 100.

On the other hand, if the corresponding value of the conditional expression (2-4) of the optical system according to the second embodiment of the present application is less than the lower limit value, it is difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (2-4) to 85. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-4) to 90.

In the optical system according to the second embodiment of the present application, the first lens group includes a plurality of positive lenses, and the positive lens arranged closest to the object among the plurality of positive lenses is represented by the following conditional expression: It is desirable to satisfy (2-5).
(2-5) 80 <νd1pf <110
However,
νd1pf: Abbe number with respect to the d-line (wavelength 587.6 nm) of the glass material of the positive lens arranged closest to the object side among the plurality of positive lenses in the first lens group

Conditional expression (2-5) defines the Abbe number of the glass material of the positive lens arranged closest to the object among the plurality of positive lenses in the first lens group. The optical system according to the second embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (2-5).

If the corresponding value of the conditional expression (2-5) of the optical system according to the second embodiment of the present application exceeds the upper limit, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-5) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-5) to 100.

On the other hand, if the corresponding value of the conditional expression (2-5) of the optical system according to the second embodiment of the present application is lower than the lower limit value, it is difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-5) to 85. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-5) to 90.

In the optical system according to the second embodiment of the present application, it is preferable that the first lens group includes at least one negative lens that satisfies the following conditional expression (2-6).
(2-6) 1.50 <nd1n <1.75
However,
nd1n: refractive index with respect to d-line (wavelength 587.6 nm) of the glass material of the negative lens in the first lens group

Conditional expression (2-6) defines the refractive index of the glass material of the negative lens in the first lens group. The optical system according to the second embodiment of the present application can satisfactorily correct coma and curvature of field while reducing the weight by satisfying conditional expression (2-6).

When the corresponding value of the conditional expression (2-6) of the optical system according to the second embodiment of the present application exceeds the upper limit value, the specific gravity of the glass material of the negative lens in the first lens group increases. Therefore, if the specific gravity of other lenses in the first lens group is reduced in order to reduce the weight of the optical system according to the second embodiment of the present application, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-6) to 1.70. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-6) to 1.65.

On the other hand, if the corresponding value of the conditional expression (2-6) of the optical system according to the second embodiment of the present application is less than the lower limit value, it becomes difficult to correct the curvature of field. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-6) to 1.55. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (2-6) to 1.60.

In addition, it is desirable that the optical system according to the second embodiment of the present application moves so that at least a part of the third lens group includes a component in a direction orthogonal to the optical axis. With this configuration, image blur due to camera shake or the like can be corrected, that is, image stabilization can be performed, and the occurrence of decentration aberrations during image stabilization can be suppressed to a level where there is no problem.

In the optical system according to the second embodiment of the present application, the third lens group includes, in order from the object side, a 3a lens group having a positive refractive power, a 3b lens group having a negative refractive power, It is desirable that the third lens unit is composed of a third lens unit having positive refractive power, and the third lens unit moves so as to include a component in a direction orthogonal to the optical axis. With this configuration, image blur due to camera shake or the like can be corrected, that is, image stabilization can be performed, and the occurrence of decentration aberrations during image stabilization can be suppressed to a level where there is no problem. In addition, since the diameter of the 3b lens group can be reduced, the mechanical unit for driving the 3b lens group during vibration isolation can be reduced in size.

In the optical system according to the second embodiment of the present application, it is desirable that the first lens group includes a cemented lens of a negative lens and a positive lens in order from the object side. With this configuration, the decentration aberration can be corrected satisfactorily. The cemented lens is more preferably arranged on the most image side in the first lens group.

In the optical system according to the second embodiment of the present application, the first lens group includes a 1a lens group and a 1b lens group in order from the object side, and the 1a lens group and the 1b lens It is desirable that the air gap with the lens group is the largest among the air gaps in the first lens group, and the following conditional expression (2-7) is satisfied.
(2-7) 0.30 <TL1a / TL1 <0.70
However,
TL1a: length along the optical axis of the first lens group TL1: length along the optical axis of the first lens group

Conditional expression (2-7) defines the length of the first lens group with respect to the length of the first lens group. The optical system according to the second embodiment of the present application can satisfactorily correct coma aberration while reducing the weight by satisfying conditional expression (2-7).

When the corresponding value of the conditional expression (2-7) of the optical system according to the second embodiment of the present application exceeds the upper limit value, the weight of the first lens group increases. Therefore, for example, if a glass material having a small refractive index is used for the negative lens in the first lens group in order to reduce the weight, it becomes difficult to correct curvature of field. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-7) to 0.60. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-7) to 0.50.

On the other hand, if the corresponding value of the conditional expression (2-7) of the optical system according to the second embodiment of the present application is less than the lower limit value, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (2-7) to 0.35. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-7) to 0.40.

In the optical system according to the second embodiment of the present application, it is preferable that the first-a lens group includes a positive lens, a positive lens, and a negative lens in order from the object side. With this configuration, it is possible to reduce the weight of the optical system according to the second embodiment of the present application.
In the optical system according to the second embodiment of the present application, it is preferable that the first lens group has a protective filter glass on the most object side. The protective filter glass is a lens having substantially no refractive power, and the focal length thereof is preferably 10 times or more the focal length of the optical system according to the second embodiment of the present application. In particular, the optical system according to the second embodiment of the present application preferably has a negative meniscus shape in which the protective filter glass has a convex surface facing the object side. With this configuration, the ghost can be cut well.
In the optical system according to the second embodiment of the present application, it is preferable that the first-b lens group includes a negative lens and a positive lens in order from the object side. With this configuration, it is possible to satisfactorily correct variations in spherical aberration when focusing on a short-distance object. In particular, in the optical system according to the second embodiment of the present application, it is preferable that the first-b lens group includes only a cemented lens of a negative lens and a positive lens in order from the object side. With this configuration, it is possible to reduce the weight of the optical system according to the second embodiment of the present application.

In the optical system according to the second embodiment of the present application, the first lens group includes a 1a lens group and a 1b lens group in order from the object side, and the 1a lens group and the 1b lens It is desirable that the air gap with the lens group is the largest of the air gaps in the first lens group, and the first b lens group has a positive lens that satisfies the following conditional expression (2-8): .
(2-8) 70 <νd1bp <110
However,
νd1bp: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the 1b lens group

Conditional expression (2-8) defines the Abbe number of the glass material of the positive lens in the 1b lens group. The optical system according to the second embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (2-8).

If the corresponding value of the conditional expression (2-8) of the optical system according to the second embodiment of the present application exceeds the upper limit, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-8) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (2-8) to 100.

On the other hand, if the corresponding value of the conditional expression (2-8) of the optical system according to the second embodiment of the present application is less than the lower limit value, it is difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-8) to 75. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (2-8) to 80.

The optical apparatus of the present application is characterized by including the optical system according to the second embodiment having the above-described configuration. Thereby, an optical device having a small size and good optical performance can be realized.

The optical system manufacturing method according to the second embodiment of the present application has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A method of manufacturing an optical system having a third lens group, wherein the second lens group has at least three lenses, and the optical system satisfies the following conditional expression (2-1): In addition, the second lens group is moved along the optical axis to focus from an object at infinity to an object at a short distance. Thereby, an optical system having a small size and good optical performance can be manufactured.
(2-1) 0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

Hereinafter, an optical system, an optical device, and an optical system manufacturing method according to the third embodiment of the present application will be described.
The optical system according to the third embodiment of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. The second lens group moves along the optical axis when focusing from an object at infinity to an object at a short distance, and a part of the third lens group is orthogonal to the optical axis as a shift lens group. And the following conditional expression (3-1) is satisfied.
(3-1) -1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

As described above, the optical system according to the third embodiment of the present application has, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, and the positive refractive power. A second lens group that moves along the optical axis during focusing from an object at infinity to an object at a short distance, and a part of the third lens group serves as a shift lens group. It moves so as to include a component in a direction orthogonal to the optical axis. With this configuration, the optical system according to the third embodiment of the present application can achieve a reduction in size and weight and excellent imaging performance.

In addition, as described above, the optical system according to the third embodiment of the present application moves so that a part of the third lens group includes a component in a direction orthogonal to the optical axis as a shift lens group. With this configuration, it is possible to correct image blur due to camera shake or the like, that is, to perform image stabilization.

Conditional expression (3-1) defines an appropriate range of the so-called blur coefficient, which is the amount of movement of the shift lens group in the direction orthogonal to the optical axis with respect to the amount of movement in the direction orthogonal to the optical axis. It is. The optical system according to the third embodiment of the present application can satisfactorily correct spherical aberration, coma aberration, and field curvature by satisfying conditional expression (3-1), and suppress deterioration of optical performance during lens shift. be able to.

When the corresponding value of the conditional expression (3-1) of the optical system according to the third embodiment of the present application exceeds the upper limit value, the image movement amount relative to the movement amount of the shift lens group becomes relatively small. This is not preferable because spherical aberration and coma are insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3-1) to −0.95. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (3-1) to -1.00.

On the other hand, when the corresponding value of conditional expression (3-1) of the optical system according to the third embodiment of the present application is less than the lower limit value, the amount of movement of the image with respect to the amount of movement of the shift lens group becomes too large. This is not preferable because coma aberration and field curvature are deteriorated. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3-1) to −1.55.
With the configuration described above, it is possible to realize an optical system that corrects various aberrations satisfactorily and suppresses deterioration of optical performance during lens shift.

In the optical system according to the third embodiment of the present application, the third lens group includes a 3a lens group, a 3b lens group, and a 3c lens group in order from the object side. It is desirable for the lens group to move so as to include a component in a direction orthogonal to the optical axis as the shift lens group. With this configuration, it is possible to correct spherical aberration and coma with the 3a lens group, and it is possible to correct spherical aberration with the 3c lens group. Therefore, spherical aberration and coma aberration can be corrected well in the entire third lens group. In addition, since the third lens group is a shift lens group, it is possible to suppress deterioration in optical performance during lens shift.

In the optical system according to the third embodiment of the present application, the third lens group includes, in order from the object side, a 3a lens group, a 3b lens group, and a 3c lens group. It is desirable that the lens group includes a positive lens and a negative lens. With this configuration, it is possible to satisfactorily correct spherical aberration and coma in the 3a lens group, and it is possible to further improve the performance of the optical system according to the third embodiment of the present application. In particular, it is more desirable that the 3a lens group has a positive refractive power.

In the optical system according to the third embodiment of the present application, it is preferable that the shift lens group includes a cemented lens of a positive lens and a negative lens and a negative lens in order from the object side. With this configuration, spherical aberration can be favorably corrected in the shift lens group, and spherical aberration and coma aberration can be favorably corrected in the entire third lens group. Thereby, the optical system according to the third embodiment of the present application can more effectively suppress the deterioration of the optical performance at the time of lens shift while further improving the performance.

In the optical system according to the third embodiment of the present application, the third lens group includes, in order from the object side, a 3a lens group, a 3b lens group, and a 3c lens group. It is desirable to have an aperture stop on the object side or image side of the lens group. With this configuration, the refractive power arrangement of the optical system according to the third embodiment of the present application, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, an aperture stop, By approaching the symmetrical type of the third lens group having positive refractive power, it is possible to satisfactorily correct field curvature and distortion. Thereby, the optical system according to the third embodiment of the present application can achieve higher performance.

In the optical system according to the third embodiment of the present application, the third lens group includes a 3a lens group, a 3b lens group, and a 3c lens group in order from the object side. It is desirable that the lens group moves as the shift lens group so as to include a component in a direction orthogonal to the optical axis, and satisfies the following conditional expression (3-2).
(3-2) -0.45 <f3a / f3bc <0.40
However,
f3a: focal length of the 3a lens group f3bc: combined focal length of the 3b lens group and the 3c lens group at the time of focusing on an object at infinity

Conditional expression (3-2) defines an appropriate range of the ratio between the focal length of the 3a lens group and the combined focal length of the 3b lens group and the 3c lens group as the shift lens group. The optical system according to the third embodiment of the present application can satisfactorily correct the spherical aberration, the coma aberration, and the fluctuation of the coma aberration at the time of lens shift by satisfying the conditional expression (3-2). As a result, the optical system according to the third embodiment of the present application can suppress deterioration in optical performance during lens shift while further improving performance.

When the corresponding value of the conditional expression (3-2) of the optical system according to the third embodiment of the present application exceeds the upper limit value, the refractive power of the 3a lens group becomes relatively small and is generated by the 3a lens group alone. Spherical aberration and coma are undercorrected. Further, the refractive powers of the shift lens group and the third c lens group become relatively large. For this reason, fluctuations in coma cannot be suppressed during lens shift, and high optical performance cannot be obtained. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3-2) to 0.35. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3-2) to 0.30.

On the other hand, when the corresponding value of the conditional expression (3-2) of the optical system according to the third embodiment of the present application is less than the lower limit value, the refractive power of the 3a lens group becomes relatively large, and the 3a lens group alone A large amount of spherical aberration and coma occur. Further, the refractive powers of the shift lens group and the third c lens group become relatively small. For this reason, coma is insufficiently corrected during lens shift. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3-2) to −0.40. In order to further secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (3-2) to −0.35.

In the optical system according to the third embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b It is desirable that the air gap with the lens group is the largest among the air gaps in the first lens group, and the first lens group has the negative lens closest to the image side. With this configuration, it is possible to suppress the occurrence of spherical aberration in the first lens unit alone, and to correct spherical aberration and coma well in the entire first lens unit. Thereby, the optical system according to the third embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

In the optical system according to the third embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b It is desirable that the air gap with the lens group is the largest of the air gaps in the first lens group, and the following conditional expression (3-3) is satisfied.
(3-3) 1.40 <f1a / f1b <2.05
However,
f1a: focal length of the 1a lens group f1b: focal length of the 1b lens group

Conditional expression (3-3) defines an appropriate range of the focal length ratio of the 1a lens group and the 1b lens group. The optical system according to the third embodiment of the present application can satisfactorily correct the spherical aberration and the coma generated in the single lens unit 1a by satisfying conditional expression (3-3). Thereby, the optical system according to the third embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

When the corresponding value of the conditional expression (3-3) of the optical system according to the third embodiment of the present application exceeds the upper limit value, the refractive power of the 1a lens group becomes relatively small, and the 1a lens group alone is generated. Spherical aberration and coma are undercorrected. In addition, since the refractive power of the first-b lens group becomes relatively large and it becomes impossible to suppress the variation of spherical aberration at the time of focusing, it becomes impossible to obtain high optical performance. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (3-3) to 2.00. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3-3) to 1.95.

On the other hand, when the corresponding value of the conditional expression (3-3) of the optical system according to the third embodiment of the present application is below the lower limit value, the refractive power of the 1a lens group becomes relatively large, and the 1a lens group alone A large amount of spherical aberration and coma occur. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3-3) to 1.45. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3-3) to 1.50.

In the optical system according to the third embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b The air gap with the lens group is the largest of the air gaps in the first lens group, and the first a lens group is in order from the object side, protective glass, positive lens, positive lens, and negative lens. It is desirable to be composed of With this configuration, spherical aberration can be favorably corrected in the 1a lens group. Thereby, the optical system according to the third embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

In the optical system according to the third embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b An air gap with the lens group is the largest of the air gaps in the first lens group, and the first b lens group includes, in order from the object side, a negative meniscus lens and a positive lens with a convex surface facing the object side. It is desirable that the lens is composed of a cemented lens. With this configuration, it is possible to satisfactorily correct spherical aberration and coma in the 1b lens group. Thereby, the optical system according to the third embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

In the optical system according to the third embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b The air gap with the lens group is the largest of the air gaps in the first lens group, and the first a lens group has at least one positive lens that satisfies the following conditional expression (3-4): It is desirable.
(3-4) 90 <νdp
However,
νdp: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the 1a lens group

Conditional expression (3-4) defines the Abbe number of the glass material of the positive lens in the 1a lens group. By satisfying conditional expression (3-4), the optical system according to the third embodiment of the present application can suppress the occurrence of longitudinal chromatic aberration and lateral chromatic aberration in the first lens unit alone.

When the corresponding value of the conditional expression (3-4) of the optical system according to the third embodiment of the present application is less than the lower limit value, axial chromatic aberration and lateral chromatic aberration are greatly generated in the first lens unit alone, and the third This is not preferable because the optical performance of the optical system according to the embodiment is deteriorated.

In the optical system according to the third embodiment of the present application, the second lens group includes a plurality of negative lenses, and the negative lens arranged closest to the image side among the plurality of negative lenses is represented by the following conditional expression: It is desirable to satisfy (3-5).
(3-5) ndn <1.65
However,
ndn: Refractive index with respect to d-line (wavelength: 587.6 nm) of the glass material of the negative lens arranged on the most image side among the plurality of negative lenses in the second lens group

Conditional expression (3-5) defines the refractive index of the glass material of the negative lens arranged closest to the image among the plurality of negative lenses in the second lens group. The optical system according to the third embodiment of the present application can satisfy the conditional expression (3-5) to suppress the occurrence of lateral chromatic aberration in the second lens unit alone.

When the corresponding value of the conditional expression (3-5) of the optical system according to the third embodiment of the present application exceeds the upper limit value, a large amount of chromatic aberration of magnification occurs in the second lens unit alone, and according to the third embodiment of the present application. This is not preferable because the optical performance of the optical system deteriorates.

In the optical system according to the third embodiment of the present application, the second lens group includes a plurality of negative lenses, and the negative lens arranged closest to the object among the plurality of negative lenses is represented by the following conditional expression: It is desirable to satisfy (3-6).
(3-6) 49.7 <νdn
However,
νdn: Abbe number with respect to d-line (wavelength: 587.6 nm) of the glass material of the negative lens arranged closest to the object among the plurality of negative lenses in the second lens group

Conditional expression (3-6) defines the Abbe number of the glass material of the negative lens disposed closest to the object among the plurality of negative lenses in the second lens group. The optical system according to the third embodiment of the present application can suppress occurrence of longitudinal chromatic aberration in the second lens unit alone by satisfying conditional expression (3-6).

When the corresponding value of the conditional expression (3-6) of the optical system according to the third embodiment of the present application is less than the lower limit value, axial chromatic aberration is greatly generated in the second lens unit alone, and the third embodiment of the present application is applied. Since the optical performance of the optical system is deteriorated, it is not preferable.

Further, it is desirable that the optical system according to the third embodiment of the present application satisfies the following conditional expression (3-7).
(3-7) -3.00 <f1 / f2 <-2.00
However,
f1: Focal length of the first lens group f2: Focal length of the second lens group

Conditional expression (3-7) defines an appropriate range of the focal length ratio between the first lens group and the second lens group. By satisfying conditional expression (3-7), the optical system according to the third embodiment of the present application suppresses fluctuations in coma during focusing, and suppresses occurrence of spherical aberration in the first lens unit alone. be able to. As a result, the optical system according to the third embodiment of the present application can achieve higher performance.

When the corresponding value of the conditional expression (3-7) of the optical system according to the third embodiment of the present application exceeds the upper limit value, the refractive power of the first lens group becomes relatively small. For this reason, the first lens group cannot contribute to reducing the tele ratio, that is, the value obtained by dividing the total length of the optical system according to the third embodiment of the present application by the focal length, and the optical system according to the third embodiment of the present application. The total length of will increase. In addition, since the refractive power of the second lens group becomes relatively large, fluctuations in coma aberration cannot be suppressed during focusing, and high optical performance cannot be obtained. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3-7) to −2.15. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (3-7) to −2.30.

On the other hand, when the corresponding value of the conditional expression (3-7) of the optical system according to the third embodiment of the present application is lower than the lower limit value, the refractive power of the first lens group becomes relatively large, and the first lens group alone A large amount of spherical aberration occurs. In addition, the refractive power of the second lens group becomes relatively small, and the amount of movement of the second lens group at the time of focusing becomes great. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3-7) to −2.85. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (3-7) to −2.70.

In the optical system according to the third embodiment of the present application, the second lens group includes, in order from the object side, a negative lens having a concave surface facing the image side, and a cemented lens of a positive lens and a negative lens. It is desirable that With this configuration, coma can be favorably corrected in the second lens group. Thereby, the optical system according to the third embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

Further, it is desirable that the optical system according to the third embodiment of the present application satisfies the following conditional expression (3-8).
(3-8) 0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

Conditional expression (3-8) defines an appropriate range of the ratio between the focal length of the optical system according to the third embodiment of the present application and the combined focal length of the first lens group and the second lens group. The optical system according to the third embodiment of the present application can satisfactorily correct coma and lateral chromatic aberration generated in the first lens group and the second lens group by satisfying conditional expression (3-8). . As a result, the optical system according to the third embodiment of the present application can achieve higher performance.

When the corresponding value of the conditional expression (3-8) of the optical system according to the third embodiment of the present application exceeds the upper limit value, the refractive power of the first lens group and the second lens group becomes relatively large, and the first lens This is not preferable because coma aberration is greatly generated in the first lens group and the second lens group. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3-8) to 0.55. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (3-8) to 0.53.

On the other hand, when the corresponding value of the conditional expression (3-8) of the optical system according to the third embodiment of the present application is lower than the lower limit value, the refractive powers of the first lens group and the second lens group become relatively small, and the first This is not preferable because the lateral chromatic aberration generated in the first lens group and the second lens group is insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3-8) to 0.20. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (3-8) to 0.30.

The optical apparatus according to the present application includes the optical system according to the third embodiment having the above-described configuration. Thereby, it is possible to realize an optical device that corrects various aberrations satisfactorily and suppresses deterioration of optical performance during lens shift.

The optical system manufacturing method according to the third embodiment of the present application has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A method of manufacturing an optical system having a third lens group, wherein the second lens group moves along an optical axis when focusing from an object at infinity to an object at a short distance, and the third lens group Is moved so as to include a component in a direction perpendicular to the optical axis as a shift lens group, and the optical system satisfies the following conditional expression (3-1). Accordingly, it is possible to manufacture an optical system that corrects various aberrations satisfactorily and suppresses deterioration of optical performance during lens shift.
(3-1) -1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

Hereinafter, an optical system, an optical device, and an optical system manufacturing method according to the fourth embodiment of the present application will be described.
The optical system according to the fourth embodiment of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. The third lens group includes a 3a lens group and a 3b lens group in order from the object side, and the second lens is in focus when focusing from an infinite object to a short distance object. The group moves along the optical axis, and the 3b lens group moves as a shift lens group so as to include a component in a direction orthogonal to the optical axis, and satisfies the following conditional expression (4-1): And
(4-1) 1.70 <| fR / fF | <5.00
However,
fF: Composite focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: Nearer to the image side than the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Combined focal length of all lenses located

As described above, the optical system according to the fourth embodiment of the present application has, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, and the positive refractive power. A third lens group, and the third lens group has a 3a lens group and a 3b lens group in order from the object side, and when focusing from an infinite object to a short distance object, The second lens group moves along the optical axis. With this configuration, the optical system according to the fourth embodiment of the present application can achieve a reduction in size and weight and excellent imaging performance.

Also, as described above, the optical system according to the fourth embodiment of the present application moves, that is, shifts the lens, so that the third lens group includes a component in a direction orthogonal to the optical axis as a shift lens group. With this configuration, it is possible to correct image blur due to camera shake or the like, that is, to perform image stabilization.

Conditional expression (4-1) indicates that the combined focal length from the first lens group to the 3a lens group and the combined focal length of all the lenses located on the image side of the 3b lens group and the 3b lens group are It defines an appropriate range of ratios. If there is no lens on the image side of the 3b lens group, the corresponding value of the conditional expression (4-1) is calculated as “fR: focal length of the 3b lens group”. By satisfying conditional expression (4-1), the optical system according to the fourth embodiment of the present application can satisfactorily correct spherical aberration and coma aberration while achieving miniaturization, and obtain excellent imaging performance. Can do.

When the corresponding value of the conditional expression (4-1) of the optical system according to the fourth embodiment of the present application exceeds the upper limit value, the combined refractive power from the first lens group to the 3a lens group becomes relatively small. This is not preferable because spherical aberration and coma aberration generated from the first lens group to the 3a lens group become insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4-1) to 4.75. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4-1) to 4.25.

On the other hand, when the corresponding value of the conditional expression (4-1) of the optical system according to the fourth embodiment of the present application is below the lower limit value, the combined refractive power from the first lens group to the 3a lens group becomes relatively large. . Accordingly, a large amount of coma aberration is generated from the first lens group to the 3a lens group, which is not preferable. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4-1) to 1.71.
With the above configuration, it is possible to realize a compact optical system having excellent optical performance by correcting various aberrations.

In addition, it is desirable that the optical system according to the fourth embodiment of the present application satisfies the following conditional expression (4-2).
(4-2) -1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

Conditional expression (4-2) defines an appropriate range of the so-called blur coefficient, which is the amount of movement of the shift lens group in the direction orthogonal to the optical axis with respect to the amount of movement in the direction orthogonal to the optical axis. It is. The optical system according to the fourth embodiment of the present application can satisfactorily correct spherical aberration, coma aberration, and field curvature by satisfying conditional expression (4-2), and suppress deterioration of optical performance during lens shift. be able to.

When the corresponding value of the conditional expression (4-2) of the optical system according to the fourth embodiment of the present application exceeds the upper limit value, the image movement amount relative to the movement amount of the shift lens group becomes relatively small. This is not preferable because spherical aberration and coma are insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (4-2) to −0.95. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (4-2) to −1.00.

On the other hand, when the corresponding value of the conditional expression (4-2) of the optical system according to the fourth embodiment of the present application is lower than the lower limit value, the moving amount of the image with respect to the moving amount of the shift lens group becomes too large. This is not preferable because coma aberration and field curvature are deteriorated. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (4-2) to −1.55.

In the optical system according to the fourth embodiment of the present application, it is preferable that the third lens group is composed of a positive lens and a negative lens. With this configuration, it is possible to satisfactorily correct spherical aberration and coma in the 3a lens group, and it is possible to further improve the performance of the optical system according to the fourth embodiment of the present application. In particular, it is more desirable that the 3a lens group has a positive refractive power.

In the optical system according to the fourth embodiment of the present application, it is preferable that the third lens group is composed of a cemented lens of a positive lens and a negative lens and a negative lens in order from the object side. With this configuration, spherical aberration can be favorably corrected in the third lens group, and spherical aberration and coma aberration can be favorably corrected in the entire third lens group. Thereby, the optical system according to the fourth embodiment of the present application can more effectively suppress the deterioration of the optical performance during the lens shift while further improving the performance.

In addition, it is desirable that the optical system according to the fourth embodiment of the present application has an aperture stop on the object side or the image side of the 3a lens group. With this configuration, the refractive power arrangement of the optical system according to the fourth embodiment of the present application, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, an aperture stop, By approaching the symmetrical type of the third lens group having positive refractive power, it is possible to satisfactorily correct field curvature and distortion. Thereby, the optical system according to the fourth embodiment of the present application can be further improved in performance.

In the optical system according to the fourth embodiment of the present application, the third lens group includes, in order from the object side, the third a lens group, the third b lens group, and a third c lens group. It is desirable that the conditional expression (4-3) is satisfied.
(4-3) -0.45 <f3a / f3bc <0.40
However,
f3a: focal length of the 3a lens group f3bc: combined focal length of the 3b lens group and the 3c lens group at the time of focusing on an object at infinity

Conditional expression (4-3) defines an appropriate range of the ratio between the focal length of the 3a lens group and the combined focal length of the 3b lens group and the 3c lens group. The optical system according to the fourth embodiment of the present application can satisfactorily correct the spherical aberration, the coma aberration, and the fluctuation of the coma aberration during the lens shift by satisfying the conditional expression (4-3). Thereby, the optical system according to the fourth embodiment of the present application can suppress deterioration in optical performance during lens shift while further improving performance.

When the corresponding value of the conditional expression (4-3) of the optical system according to the fourth embodiment of the present application exceeds the upper limit value, the refractive power of the 3a lens group becomes relatively small, and the 3a lens group alone is generated. Spherical aberration and coma are undercorrected. Further, the refractive power of the third b lens group and the third c lens group becomes relatively large. For this reason, fluctuations in coma cannot be suppressed during lens shift, and high optical performance cannot be obtained. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4-3) to 0.35. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (4-3) to 0.30.

On the other hand, when the corresponding value of the conditional expression (4-3) of the optical system according to the fourth embodiment of the present application is below the lower limit value, the refractive power of the 3a lens group becomes relatively large, and the 3a lens group alone A large amount of spherical aberration and coma occur. Further, the refractive power of the third b lens group and the third c lens group becomes relatively small. For this reason, coma is insufficiently corrected during lens shift. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4-3) to −0.40. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4-3) to −0.35.

In the optical system according to the fourth embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b It is desirable that the air gap with the lens group is the largest among the air gaps in the first lens group, and the first lens group has the negative lens closest to the image side. With this configuration, it is possible to suppress the occurrence of spherical aberration in the first lens unit alone, and to correct spherical aberration and coma well in the entire first lens unit. Thereby, the optical system according to the fourth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

In the optical system according to the fourth embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b It is desirable that the air gap with the lens group is the largest of the air gaps in the first lens group and the following conditional expression (4-4) is satisfied.
(4-4) 1.40 <f1a / f1b <2.05
However,
f1a: focal length of the 1a lens group f1b: focal length of the 1b lens group

Conditional expression (4-4) defines an appropriate range of the focal length ratio of the 1a lens group and the 1b lens group. The optical system according to the fourth embodiment of the present application can satisfactorily correct spherical aberration and coma generated in the first lens group alone by satisfying conditional expression (4-4). Thereby, the optical system according to the fourth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

When the corresponding value of the conditional expression (4-4) of the optical system according to the fourth embodiment of the present application exceeds the upper limit value, the refractive power of the 1a lens group becomes relatively small, and the 1a lens group alone is generated. Spherical aberration and coma are undercorrected. In addition, since the refractive power of the first-b lens group becomes relatively large and it becomes impossible to suppress the variation of spherical aberration at the time of focusing, it becomes impossible to obtain high optical performance. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4-4) to 2.00. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4-4) to 1.95.

On the other hand, when the corresponding value of the conditional expression (4-4) of the optical system according to the fourth embodiment of the present application is below the lower limit value, the refractive power of the 1a lens group becomes relatively large, and the 1a lens group alone A large amount of spherical aberration and coma occur. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4-4) to 1.45. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4-4) to 1.50.

In the optical system according to the fourth embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b The air gap with the lens group is the largest of the air gaps in the first lens group, and the first a lens group is in order from the object side, protective glass, positive lens, positive lens, and negative lens. It is desirable to be composed of With this configuration, spherical aberration can be favorably corrected in the 1a lens group. Thereby, the optical system according to the fourth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

In the optical system according to the fourth embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b An air gap with the lens group is the largest of the air gaps in the first lens group, and the first b lens group includes, in order from the object side, a negative meniscus lens and a positive lens with a convex surface facing the object side. It is desirable that the lens is composed of a cemented lens. With this configuration, it is possible to satisfactorily correct spherical aberration and coma in the 1b lens group. Thereby, the optical system according to the fourth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

In the optical system according to the fourth embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b The air gap with the lens group is the largest of the air gaps in the first lens group, and the first a lens group has at least one positive lens that satisfies the following conditional expression (4-5) It is desirable.
(4-5) 90 <νdp
However,
νdp: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the 1a lens group

Conditional expression (4-5) defines the Abbe number of the glass material of the positive lens in the 1a lens group. By satisfying conditional expression (4-5), the optical system according to the fourth embodiment of the present application can suppress occurrence of longitudinal chromatic aberration and lateral chromatic aberration in the first lens unit alone.

When the corresponding value of the conditional expression (4-5) of the optical system according to the fourth embodiment of the present application is lower than the lower limit value, axial chromatic aberration and lateral chromatic aberration are greatly generated in the first lens unit alone, and the fourth lens of the present application. This is not preferable because the optical performance of the optical system according to the embodiment is deteriorated.

In the optical system according to the fourth embodiment of the present application, the second lens group includes a plurality of negative lenses, and the negative lens arranged closest to the image side among the plurality of negative lenses is represented by the following conditional expression: It is desirable to satisfy (4-6).
(4-6) ndn <1.65
However,
ndn: Refractive index with respect to d-line (wavelength: 587.6 nm) of the glass material of the negative lens arranged on the most image side among the plurality of negative lenses in the second lens group

Conditional expression (4-6) defines the refractive index of the glass material of the negative lens disposed closest to the image side among the plurality of negative lenses in the second lens group. The optical system according to the fourth embodiment of the present application can satisfy the conditional expression (4-6) and suppress the occurrence of lateral chromatic aberration in the second lens unit alone.

If the corresponding value of the conditional expression (4-6) of the optical system according to the fourth embodiment of the present application exceeds the upper limit value, a large amount of chromatic aberration of magnification occurs in the second lens unit alone, and according to the fourth embodiment of the present application. This is not preferable because the optical performance of the optical system deteriorates.

In the optical system according to the fourth embodiment of the present application, the second lens group includes a plurality of negative lenses, and the negative lens arranged closest to the object among the plurality of negative lenses is represented by the following conditional expression: It is desirable to satisfy (4-7).
(4-7) 49.7 <νdn
However,
νdn: Abbe number with respect to d-line (wavelength: 587.6 nm) of the glass material of the negative lens arranged closest to the object among the plurality of negative lenses in the second lens group

Conditional expression (4-7) defines the Abbe number of the glass material of the negative lens disposed closest to the object among the plurality of negative lenses in the second lens group. The optical system according to the fourth embodiment of the present application can suppress the occurrence of longitudinal chromatic aberration in the second lens unit alone by satisfying conditional expression (4-7).

When the corresponding value of the conditional expression (4-7) of the optical system according to the fourth embodiment of the present application is less than the lower limit value, a large amount of axial chromatic aberration occurs in the second lens unit alone, and the fourth embodiment of the present application Since the optical performance of the optical system is deteriorated, it is not preferable.

In addition, it is desirable that the optical system according to the fourth embodiment of the present application satisfies the following conditional expression (4-8).
(4-8) -3.00 <f1 / f2 <-2.00
However,
f1: Focal length of the first lens group f2: Focal length of the second lens group

Conditional expression (4-8) defines an appropriate range of the focal length ratio between the first lens group and the second lens group. The optical system according to the fourth embodiment of the present application satisfies the conditional expression (4-8), thereby suppressing fluctuations in coma during focusing and suppressing occurrence of spherical aberration in the first lens unit alone. be able to. As a result, the optical system according to the fourth embodiment of the present application can achieve higher performance.

When the corresponding value of the conditional expression (4-8) of the optical system according to the fourth embodiment of the present application exceeds the upper limit value, the refractive power of the first lens group becomes relatively small. For this reason, the first lens group cannot contribute to reducing the tele ratio, that is, the value obtained by dividing the total length of the optical system according to the fourth embodiment of the present application by the focal length, and the optical system according to the fourth embodiment of the present application. The total length of will increase. In addition, since the refractive power of the second lens group becomes relatively large, fluctuations in coma aberration cannot be suppressed during focusing, and high optical performance cannot be obtained. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4-8) to −2.15. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (4-8) to −2.30.

On the other hand, when the corresponding value of the conditional expression (4-8) of the optical system according to the fourth embodiment of the present application is below the lower limit value, the refractive power of the first lens group becomes relatively large, and the first lens group alone A large amount of spherical aberration occurs. In addition, the refractive power of the second lens group becomes relatively small, and the amount of movement of the second lens group at the time of focusing becomes great. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4-8) to −2.85. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (4-8) to −2.70.

In the optical system according to the fourth embodiment of the present application, the second lens group includes, in order from the object side, a negative lens having a concave surface directed toward the image side, and a cemented lens of the positive lens and the negative lens. It is desirable that With this configuration, coma can be favorably corrected in the second lens group. Thereby, the optical system according to the fourth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

In addition, it is desirable that the optical system according to the fourth embodiment of the present application satisfies the following conditional expression (4-9).
(4-9) 0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

Conditional expression (4-9) defines an appropriate range of the ratio between the focal length of the optical system according to the fourth embodiment of the present application and the combined focal length of the first lens group and the second lens group. The optical system according to the fourth embodiment of the present application can satisfactorily correct coma and lateral chromatic aberration generated in the first lens group and the second lens group by satisfying conditional expression (4-9). . As a result, the optical system according to the fourth embodiment of the present application can achieve higher performance.

When the corresponding value of the conditional expression (4-9) of the optical system according to the fourth embodiment of the present application exceeds the upper limit value, the refractive power of the first lens group and the second lens group becomes relatively large, and the first lens This is not preferable because coma aberration is greatly generated in the first lens group and the second lens group. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4-9) to 0.55. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (4-9) to 0.53.

On the other hand, when the corresponding value of the conditional expression (4-9) of the optical system according to the fourth embodiment of the present application is less than the lower limit value, the refractive powers of the first lens group and the second lens group become relatively small, and the first This is not preferable because the lateral chromatic aberration generated in the first lens group and the second lens group is insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4-9) to 0.20. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (4-9) to 0.30.

In the optical system according to the fourth embodiment of the present application, the third lens group includes, in order from the object side, the third a lens group, the third b lens group, and a third c lens group. It is desirable. With this configuration, it is possible to correct spherical aberration and coma with the 3a lens group, and it is possible to correct spherical aberration with the 3c lens group. Therefore, spherical aberration and coma aberration can be corrected well in the entire third lens group. In addition, since at least a part of the third lens group is a shift lens group, it is possible to suppress deterioration in optical performance during lens shift.

The optical apparatus according to the present application includes the optical system according to the fourth embodiment having the above-described configuration. As a result, it is possible to realize an optical device that is compact and has excellent optical performance by satisfactorily correcting various aberrations.

The optical system manufacturing method according to the fourth embodiment of the present application has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A method of manufacturing an optical system having a third lens group, wherein the third lens group includes, in order from the object side, a 3a lens group and a 3b lens group, and a short distance from an infinite object. When focusing on an object, the second lens group is moved along the optical axis, and the third b lens group is moved as a shift lens group so as to include a component in a direction perpendicular to the optical axis, The optical system satisfies the following conditional expression (4-1). As a result, it is possible to manufacture an optical system that is small in size and corrects various aberrations and has excellent optical performance.
(4-1) 1.70 <| fR / fF | <5.00
However,
fF: Composite focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: Nearer to the image side than the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Combined focal length of all lenses located

Hereinafter, an optical system, an optical device, and an optical system manufacturing method according to the fifth embodiment of the present application will be described.
The optical system according to the fifth embodiment of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. An antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is subjected to a wet process. The third lens group includes a 3a lens group and a 3b lens group in order from the object side, from an infinite object to a close object. At the time of focusing, the second lens group moves along the optical axis, and the third b lens group moves as a shift lens group so as to include a component in a direction orthogonal to the optical axis, and the following conditional expression (5- 1) is satisfied.
(5-1) 1.70 <| fR / fF | <5.00
However,
fF: Composite focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: Nearer to the image side than the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Combined focal length of all lenses located

As described above, the optical system according to the fifth embodiment of the present application has, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, and the positive refractive power. A third lens group, and the third lens group has a 3a lens group and a 3b lens group in order from the object side, and when focusing from an infinite object to a short distance object, The second lens group moves along the optical axis. With this configuration, the optical system according to the fifth embodiment of the present application can achieve a reduction in size and weight and excellent imaging performance.

Also, as described above, the optical system according to the fifth embodiment of the present application moves, that is, shifts the lens, so that the third lens group includes a component in a direction orthogonal to the optical axis as a shift lens group. With this configuration, it is possible to correct image blur due to camera shake or the like, that is, to perform image stabilization.

Conditional expression (5-1) indicates that the combined focal length from the first lens group to the 3a lens group and the combined focal length of all the lenses located on the image side of the 3b lens group and the 3b lens group are It defines an appropriate range of ratios. If no lens is present on the image side of the 3b lens group, the corresponding value of the conditional expression (5-1) is calculated as “fR: focal length of the 3b lens group”. By satisfying conditional expression (5-1), the optical system according to the fifth embodiment of the present application can satisfactorily correct spherical aberration and coma aberration while achieving miniaturization, and obtain excellent imaging performance. Can do.

When the corresponding value of the conditional expression (5-1) of the optical system according to the fifth embodiment of the present application exceeds the upper limit value, the combined refractive power from the first lens group to the 3a lens group becomes relatively small. This is not preferable because spherical aberration and coma aberration generated from the first lens group to the 3a lens group become insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (5-1) to 4.75. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5-1) to 4.25.

On the other hand, when the corresponding value of the conditional expression (5-1) of the optical system according to the fifth embodiment of the present application is below the lower limit value, the combined refractive power from the first lens group to the 3a lens group becomes relatively large. . Accordingly, a large amount of coma aberration is generated from the first lens group to the 3a lens group, which is not preferable. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5-1) to 1.71.
With the above configuration, it is possible to realize a compact optical system having excellent optical performance by correcting various aberrations.

In the optical system according to the fifth embodiment of the present application, an antireflection film is provided on at least one of the optical surfaces in the first lens group, the second lens group, and the third lens group, The antireflection film includes at least one layer formed by a wet process. With this configuration, the optical system according to the fifth embodiment of the present application can further reduce ghosts and flares caused by reflection of light from an object on an optical surface, and achieve high imaging performance. it can.

Further, in the optical system according to the fifth embodiment of the present application, the antireflection film is a multilayer film, and the layer formed by using the wet process is the most surface side of the layers constituting the multilayer film. A layer is desirable. With this configuration, the refractive index difference between the layer formed using the wet process and air can be reduced, so that the reflection of light can be further reduced and ghosts and flares can be further reduced. Can do.

Further, in the optical system according to the fifth embodiment of the present application, when the refractive index with respect to the d line (wavelength λ = 587.6 nm) of the layer formed by using the wet process is nd, nd is 1.30 or less. It is desirable that With this configuration, the refractive index difference between the layer formed using the wet process and air can be reduced, so that the reflection of light can be further reduced and ghosts and flares can be further reduced. Can do.

In the optical system according to the fifth embodiment of the present application, it is preferable that the optical surface provided with the antireflection film is a concave lens surface when viewed from the image surface side. Of the optical surfaces in the first lens group, the second lens group, and the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image plane side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the fifth embodiment of the present application, it is desirable that the concave lens surface viewed from the image surface side is an image surface side lens surface of the lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the fifth embodiment of the present application, it is desirable that the concave lens surface when viewed from the image surface side is an image surface side lens surface of a lens in the second lens group. Of the optical surfaces in the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the fifth embodiment of the present application, it is preferable that the concave lens surface viewed from the image surface side is an object side lens surface of the lens in the third lens group. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the fifth embodiment of the present application, it is desirable that the concave lens surface when viewed from the image surface side is an image surface side lens surface of a lens in the third lens group. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the fifth embodiment of the present application, the concave lens surface viewed from the image surface side is the image surface side lens surface of the fourth lens from the object side in the third lens group. It is desirable. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the fifth embodiment of the present application, it is preferable that the optical surface provided with the antireflection film is a concave lens surface when viewed from the object side. Of the optical surfaces in the first lens group and the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the fifth embodiment of the present application, it is desirable that the concave lens surface when viewed from the object side is the object-side lens surface of the lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the fifth embodiment of the present application, it is desirable that the concave lens surface viewed from the object side is an image surface side lens surface of the lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the fifth embodiment of the present application, it is desirable that the concave lens surface when viewed from the object side is the object-side lens surface of the lens in the second lens group. Of the optical surfaces in the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

Note that the antireflection film in the optical system according to the fifth embodiment of the present application is not limited to a wet process, and may be formed by a dry process or the like. In this case, the antireflection film preferably includes at least one layer having a refractive index of 1.30 or less. With this configuration, even when the antireflection film is formed by a dry process or the like, the same effect as when the antireflection film is formed by a wet process can be obtained. Note that the layer having a refractive index of 1.30 or less is preferably the outermost layer among the layers constituting the multilayer film.

Further, it is desirable that the optical system according to the fifth embodiment of the present application satisfies the following conditional expression (5-2).
(5-2) -1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

Conditional expression (5-2) defines an appropriate range of the so-called blur coefficient, which is the amount of movement of the shift lens group in the direction orthogonal to the optical axis with respect to the amount of movement in the direction orthogonal to the optical axis. It is. The optical system according to the fifth embodiment of the present application can satisfactorily correct spherical aberration, coma aberration, and field curvature by satisfying conditional expression (5-2), and suppress deterioration of optical performance during lens shift. be able to.

When the corresponding value of the conditional expression (5-2) of the optical system according to the fifth embodiment of the present application exceeds the upper limit value, the image movement amount relative to the movement amount of the shift lens group becomes relatively small. This is not preferable because spherical aberration and coma are insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5-2) to −0.95. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (5-2) to -1.00.

On the other hand, if the corresponding value of the conditional expression (5-2) of the optical system according to the fifth embodiment of the present application is less than the lower limit value, the amount of movement of the image with respect to the amount of movement of the shift lens group becomes too large. This is not preferable because coma aberration and field curvature are deteriorated. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5-2) to −1.55.

In the optical system according to the fifth embodiment of the present application, it is desirable that the third lens group is composed of a positive lens and a negative lens. With this configuration, it is possible to satisfactorily correct spherical aberration and coma in the 3a lens group, and it is possible to further improve the performance of the optical system according to the fifth embodiment of the present application. In particular, it is more desirable that the 3a lens group has a positive refractive power.

In the optical system according to the fifth embodiment of the present application, it is desirable that the third lens group is composed of a cemented lens of a positive lens and a negative lens and a negative lens in order from the object side. With this configuration, spherical aberration can be favorably corrected in the third lens group, and spherical aberration and coma aberration can be favorably corrected in the entire third lens group. Thereby, the optical system according to the fifth embodiment of the present application can more effectively suppress the deterioration of the optical performance during the lens shift while further improving the performance.

It is desirable that the optical system according to the fifth embodiment of the present application has an aperture stop on the object side or the image side of the 3a lens group. With this configuration, the refractive power arrangement of the optical system according to the fifth embodiment of the present application, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, an aperture stop, By approaching the symmetrical type of the third lens group having positive refractive power, it is possible to satisfactorily correct field curvature and distortion. Thereby, the optical system according to the fifth embodiment of the present application can be further improved in performance.

In the optical system according to the fifth embodiment of the present application, the third lens group includes, in order from the object side, the third a lens group, the third b lens group, and a third c lens group. It is desirable that the conditional expression (5-3) is satisfied.
(5-3) -0.45 <f3a / f3bc <0.40
However,
f3a: focal length of the 3a lens group f3bc: combined focal length of the 3b lens group and the 3c lens group at the time of focusing on an object at infinity

Conditional expression (5-3) defines an appropriate range of the ratio between the focal length of the 3a lens group and the combined focal length of the 3b lens group and the 3c lens group. The optical system according to the fifth embodiment of the present application can satisfactorily correct the spherical aberration, the coma aberration, and the fluctuation of the coma aberration at the time of lens shift by satisfying the conditional expression (5-3). Thereby, the optical system according to the fifth embodiment of the present application can suppress deterioration of the optical performance during lens shift while further improving the performance.

When the corresponding value of the conditional expression (5-3) of the optical system according to the fifth embodiment of the present application exceeds the upper limit value, the refractive power of the 3a lens group becomes relatively small and is generated by the 3a lens group alone. Spherical aberration and coma are undercorrected. Further, the refractive power of the third b lens group and the third c lens group becomes relatively large. For this reason, fluctuations in coma cannot be suppressed during lens shift, and high optical performance cannot be obtained. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (5-3) to 0.35. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5-3) to 0.30.

On the other hand, when the corresponding value of the conditional expression (5-3) of the optical system according to the fifth embodiment of the present application is below the lower limit value, the refractive power of the 3a lens group becomes relatively large, and the 3a lens group alone A large amount of spherical aberration and coma occur. Further, the refractive power of the third b lens group and the third c lens group becomes relatively small. For this reason, coma is insufficiently corrected during lens shift. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5-3) to −0.40. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5-3) to −0.35.

In the optical system according to the fifth embodiment of the present application, the first lens group includes, in order from the object side, a first-a lens group and a first-b lens group. The first-a lens group and the first-b It is desirable that the air gap with the lens group is the largest among the air gaps in the first lens group, and the first lens group has the negative lens closest to the image side. With this configuration, it is possible to suppress the occurrence of spherical aberration in the first lens unit alone, and to correct spherical aberration and coma well in the entire first lens unit. Thereby, the optical system according to the fifth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

In the optical system according to the fifth embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b It is desirable that the air gap with the lens group is the largest among the air gaps in the first lens group, and the following conditional expression (5-4) is satisfied.
(5-4) 1.40 <f1a / f1b <2.05
However,
f1a: focal length of the 1a lens group f1b: focal length of the 1b lens group

Conditional expression (5-4) defines an appropriate range of the focal length ratio of the 1a lens group and the 1b lens group. The optical system according to the fifth embodiment of the present application can satisfactorily correct the spherical aberration and the coma generated in the single lens unit 1a by satisfying conditional expression (5-4). Thereby, the optical system according to the fifth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

When the corresponding value of the conditional expression (5-4) of the optical system according to the fifth embodiment of the present application exceeds the upper limit value, the refractive power of the 1a lens group becomes relatively small, and the 1a lens group alone is generated. Spherical aberration and coma are undercorrected. In addition, since the refractive power of the first-b lens group becomes relatively large and it becomes impossible to suppress the variation of spherical aberration at the time of focusing, it becomes impossible to obtain high optical performance. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5-4) to 2.00. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5-4) to 1.95.

On the other hand, when the corresponding value of the conditional expression (5-4) of the optical system according to the fifth embodiment of the present application is below the lower limit value, the refractive power of the 1a lens group becomes relatively large, and the 1a lens group alone A large amount of spherical aberration and coma occur. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5-4) to 1.45. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5-4) to 1.50.

In the optical system according to the fifth embodiment of the present application, the first lens group includes, in order from the object side, a first-a lens group and a first-b lens group. The first-a lens group and the first-b The air gap with the lens group is the largest of the air gaps in the first lens group, and the first a lens group is in order from the object side, protective glass, positive lens, positive lens, and negative lens. It is desirable to be composed of With this configuration, spherical aberration can be favorably corrected in the 1a lens group. Thereby, the optical system according to the fifth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

In the optical system according to the fifth embodiment of the present application, the first lens group includes, in order from the object side, a first-a lens group and a first-b lens group. The first-a lens group and the first-b An air gap with the lens group is the largest of the air gaps in the first lens group, and the first b lens group includes, in order from the object side, a negative meniscus lens and a positive lens with a convex surface facing the object side. It is desirable that the lens is composed of a cemented lens. With this configuration, it is possible to satisfactorily correct spherical aberration and coma in the 1b lens group. Thereby, the optical system according to the fifth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

In the optical system according to the fifth embodiment of the present application, the first lens group includes, in order from the object side, a first-a lens group and a first-b lens group. The first-a lens group and the first-b The air gap with the lens group is the largest of the air gaps in the first lens group, and the first a lens group has at least one positive lens that satisfies the following conditional expression (5-5) It is desirable.
(5-5) 90 <νdp
However,
νdp: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the 1a lens group

Conditional expression (5-5) defines the Abbe number of the glass material of the positive lens in the 1a lens group. The optical system according to the fifth embodiment of the present application can suppress occurrence of longitudinal chromatic aberration and lateral chromatic aberration in the first lens unit alone by satisfying conditional expression (5-5).

When the corresponding value of the conditional expression (5-5) of the optical system according to the fifth embodiment of the present application is lower than the lower limit value, a large amount of axial chromatic aberration and lateral chromatic aberration are generated in the first lens unit alone. This is not preferable because the optical performance of the optical system according to the embodiment is deteriorated.

In the optical system according to the fifth embodiment of the present application, the second lens group includes a plurality of negative lenses, and the negative lens arranged closest to the image side among the plurality of negative lenses is represented by the following conditional expression: It is desirable to satisfy (5-6).
(5-6) ndn <1.65
However,
ndn: Refractive index with respect to d-line (wavelength: 587.6 nm) of the glass material of the negative lens arranged on the most image side among the plurality of negative lenses in the second lens group

Conditional expression (5-6) defines the refractive index of the glass material of the negative lens arranged closest to the image among the plurality of negative lenses in the second lens group. The optical system according to the fifth embodiment of the present application can suppress the occurrence of lateral chromatic aberration in the second lens unit alone by satisfying conditional expression (5-6).

When the corresponding value of the conditional expression (5-6) of the optical system according to the fifth embodiment of the present application exceeds the upper limit value, a large amount of chromatic aberration of magnification occurs in the second lens unit alone, and according to the fifth embodiment of the present application. This is not preferable because the optical performance of the optical system deteriorates.

In the optical system according to the fifth embodiment of the present application, the second lens group includes a plurality of negative lenses, and the negative lens arranged closest to the object among the plurality of negative lenses is represented by the following conditional expression: It is desirable to satisfy (5-7).
(5-7) 49.7 <νdn
However,
νdn: Abbe number with respect to d-line (wavelength: 587.6 nm) of the glass material of the negative lens arranged closest to the object among the plurality of negative lenses in the second lens group

Conditional expression (5-7) defines the Abbe number of the glass material of the negative lens disposed closest to the object among the plurality of negative lenses in the second lens group. The optical system according to the fifth embodiment of the present application can suppress the occurrence of longitudinal chromatic aberration in the second lens unit alone by satisfying conditional expression (5-7).

When the corresponding value of the conditional expression (5-7) of the optical system according to the fifth embodiment of the present application is less than the lower limit value, a large amount of axial chromatic aberration occurs in the second lens unit alone, and the fifth embodiment of the present application Since the optical performance of the optical system is deteriorated, it is not preferable.

In addition, it is desirable that the optical system according to the fifth embodiment of the present application satisfies the following conditional expression (5-8).
(5-8) -3.00 <f1 / f2 <-2.00
However,
f1: Focal length of the first lens group f2: Focal length of the second lens group

Conditional expression (5-8) defines an appropriate range of the focal length ratio between the first lens group and the second lens group. By satisfying conditional expression (5-8), the optical system according to the fifth embodiment of the present application suppresses fluctuations in coma during focusing and suppresses occurrence of spherical aberration in the first lens unit alone. be able to. Thereby, the optical system according to the fifth embodiment of the present application can achieve higher performance.

When the corresponding value of the conditional expression (5-8) of the optical system according to the fifth embodiment of the present application exceeds the upper limit value, the refractive power of the first lens group becomes relatively small. For this reason, the first lens group cannot contribute to reducing the tele ratio, that is, the value obtained by dividing the total length of the optical system according to the fifth embodiment of the present application by the focal length, and the optical system according to the fifth embodiment of the present application. The total length of will increase. In addition, since the refractive power of the second lens group becomes relatively large, fluctuations in coma aberration cannot be suppressed during focusing, and high optical performance cannot be obtained. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5-8) to −2.15. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (5-8) to −2.30.

On the other hand, when the corresponding value of the conditional expression (5-8) of the optical system according to the fifth embodiment of the present application is lower than the lower limit value, the refractive power of the first lens group becomes relatively large, and the first lens group alone A large amount of spherical aberration occurs. In addition, the refractive power of the second lens group becomes relatively small, and the amount of movement of the second lens group at the time of focusing becomes great. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5-8) to −2.85. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (5-8) to −2.70.

In the optical system according to the fifth embodiment of the present application, the second lens group includes, in order from the object side, a negative lens having a concave surface facing the image side, and a cemented lens of a positive lens and a negative lens. It is desirable that With this configuration, coma can be favorably corrected in the second lens group. Thereby, the optical system according to the fifth embodiment of the present application can suppress deterioration of the optical performance at the time of focusing while further improving the performance.

In addition, it is desirable that the optical system according to the fifth embodiment of the present application satisfies the following conditional expression (5-9).
(5-9) 0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

Conditional expression (5-9) defines an appropriate range of the ratio between the focal length of the optical system according to the fifth embodiment of the present application and the combined focal length of the first lens group and the second lens group. The optical system according to the fifth embodiment of the present application can satisfactorily correct coma and lateral chromatic aberration generated in the first lens group and the second lens group by satisfying conditional expression (5-9). . As a result, the optical system according to the fifth embodiment of the present application can achieve higher performance.

When the corresponding value of the conditional expression (5-9) of the optical system according to the fifth embodiment of the present application exceeds the upper limit value, the refractive power of the first lens group and the second lens group becomes relatively large, and the first lens This is not preferable because coma aberration is greatly generated in the first lens group and the second lens group. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5-9) to 0.55. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (5-9) to 0.53.

On the other hand, when the corresponding value of the conditional expression (5-9) of the optical system according to the fifth embodiment of the present application is less than the lower limit value, the refractive powers of the first lens group and the second lens group become relatively small, and the first This is not preferable because the lateral chromatic aberration generated in the first lens group and the second lens group is insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5-9) to 0.20. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (5-9) to 0.30.

In the optical system according to the fifth embodiment of the present application, the third lens group includes, in order from the object side, the third a lens group, the third b lens group, and a third c lens group. It is desirable. With this configuration, it is possible to correct spherical aberration and coma with the 3a lens group, and it is possible to correct spherical aberration with the 3c lens group. Therefore, spherical aberration and coma aberration can be corrected well in the entire third lens group. In addition, since at least a part of the third lens group is a shift lens group, it is possible to suppress deterioration in optical performance during lens shift.

The optical apparatus according to the present application includes the optical system according to the fifth embodiment having the above-described configuration. As a result, it is possible to realize an optical device that is compact and has excellent optical performance by satisfactorily correcting various aberrations.

The optical system manufacturing method according to the fifth embodiment of the present application has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A method of manufacturing an optical system having a third lens group, wherein an antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, The antireflection film includes at least one layer formed by a wet process, and the third lens group includes a 3a lens group and a 3b lens group in order from the object side, and is infinite. The second lens group is moved along the optical axis at the time of focusing from a far object to a short distance object, and the third b lens group includes a component in a direction orthogonal to the optical axis as a shift lens group. Move so that the optical system Characterized in that so as to satisfy under condition (5-1). As a result, it is possible to manufacture an optical system that is small in size and corrects various aberrations and has excellent optical performance.
(5-1) 1.70 <| fR / fF | <5.00
However,
fF: Composite focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: Nearer to the image side than the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Combined focal length of all lenses located

Next, an optical system, an optical device, and an optical system manufacturing method according to a sixth embodiment of the present application will be described.
The optical system according to the sixth embodiment of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. An antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is subjected to a wet process. The second lens group moves along the optical axis during focusing from an object at infinity to a near object, and a part of the third lens group The shift lens unit moves so as to include a component in a direction orthogonal to the optical axis, and satisfies the following conditional expression (6-1).
(6-1) −1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

As described above, the optical system according to the sixth embodiment of the present application has, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, and the positive refractive power. A second lens group that moves along the optical axis during focusing from an object at infinity to an object at a short distance, and a part of the third lens group serves as a shift lens group. It moves so as to include a component in a direction orthogonal to the optical axis. With this configuration, the optical system according to the sixth embodiment of the present application can achieve a reduction in size and weight and excellent imaging performance.

Also, as described above, the optical system according to the sixth embodiment of the present application moves so that a part of the third lens group includes a component in a direction orthogonal to the optical axis as a shift lens group. With this configuration, it is possible to correct image blur due to camera shake or the like, that is, to perform image stabilization.

Conditional expression (6-1) defines an appropriate range of the so-called blur coefficient, which is the amount of movement in the direction perpendicular to the optical axis of the image with respect to the amount of movement of the shift lens group in the direction perpendicular to the optical axis. It is. By satisfying conditional expression (6-1), the optical system according to the sixth embodiment of the present application can satisfactorily correct spherical aberration, coma aberration, and field curvature, and suppress deterioration in optical performance during lens shift. be able to.

When the corresponding value of the conditional expression (6-1) of the optical system according to the sixth embodiment of the present application exceeds the upper limit value, the moving amount of the image with respect to the moving amount of the shift lens group becomes relatively small. This is not preferable because spherical aberration and coma are insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (6-1) to −0.95. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (6-1) to −1.00.

On the other hand, when the corresponding value of conditional expression (6-1) of the optical system according to the sixth embodiment of the present application is less than the lower limit value, the amount of movement of the image with respect to the amount of movement of the shift lens group becomes too large. This is not preferable because coma aberration and field curvature are deteriorated. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (6-1) to −1.55.
With the configuration described above, it is possible to realize an optical system that corrects various aberrations satisfactorily and suppresses deterioration of optical performance during lens shift.

In the optical system according to the sixth embodiment of the present application, an antireflection film is provided on at least one of the optical surfaces in the first lens group, the second lens group, and the third lens group, The antireflection film includes at least one layer formed by a wet process. With this configuration, the optical system according to the sixth embodiment of the present application can further reduce ghosts and flares caused by reflection of light from an object on an optical surface, and achieve high imaging performance. it can.

Further, in the optical system according to the sixth embodiment of the present application, the antireflection film is a multilayer film, and the layer formed by using the wet process is the most surface side of the layers constituting the multilayer film. A layer is desirable. With this configuration, the refractive index difference between the layer formed using the wet process and air can be reduced, so that the reflection of light can be further reduced and ghosts and flares can be further reduced. Can do.

In the optical system according to the sixth embodiment of the present application, when the refractive index with respect to the d-line (wavelength λ = 587.6 nm) of the layer formed by using the wet process is nd, nd is 1.30 or less. It is desirable that With this configuration, the refractive index difference between the layer formed using the wet process and air can be reduced, so that the reflection of light can be further reduced and ghosts and flares can be further reduced. Can do.

In the optical system according to the sixth embodiment of the present application, it is preferable that the optical surface provided with the antireflection film is a concave lens surface when viewed from the image surface side. Of the optical surfaces in the first lens group, the second lens group, and the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image plane side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the sixth embodiment of the present application, it is desirable that the concave lens surface when viewed from the image surface side is an image surface side lens surface of a lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the sixth embodiment of the present application, it is desirable that the concave lens surface when viewed from the image surface side is an image surface side lens surface of the lens in the second lens group. Of the optical surfaces in the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the sixth embodiment of the present application, it is preferable that the concave lens surface as viewed from the image surface side be an object side lens surface of a lens in the third lens group. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the sixth embodiment of the present application, it is desirable that the concave lens surface when viewed from the image surface side is an image surface side lens surface of a lens in the third lens group. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the sixth embodiment of the present application, the concave lens surface viewed from the image surface side is the image surface side lens surface of the fourth lens from the object side in the third lens group. It is desirable. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the sixth embodiment of the present application, it is preferable that the optical surface provided with the antireflection film is a concave lens surface when viewed from the object side. Of the optical surfaces in the first lens group and the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the sixth embodiment of the present application, it is desirable that the concave lens surface when viewed from the object side is an object-side lens surface of the lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the sixth embodiment of the present application, it is desirable that the concave lens surface as viewed from the object side is an image surface side lens surface of the lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the sixth embodiment of the present application, it is desirable that the concave lens surface when viewed from the object side is the object-side lens surface of the lens in the second lens group. Of the optical surfaces in the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

Note that the antireflection film in the optical system according to the sixth embodiment of the present application is not limited to a wet process, and may be formed by a dry process or the like. In this case, the antireflection film preferably includes at least one layer having a refractive index of 1.30 or less. With this configuration, even when the antireflection film is formed by a dry process or the like, the same effect as when the antireflection film is formed by a wet process can be obtained. Note that the layer having a refractive index of 1.30 or less is preferably the outermost layer among the layers constituting the multilayer film.

In the optical system according to the sixth embodiment of the present application, the third lens group includes, in order from the object side, a third a lens group, a third b lens group, and a third c lens group, and the third b It is desirable for the lens group to move so as to include a component in a direction orthogonal to the optical axis as the shift lens group. With this configuration, it is possible to correct spherical aberration and coma with the 3a lens group, and it is possible to correct spherical aberration with the 3c lens group. Therefore, spherical aberration and coma aberration can be corrected well in the entire third lens group. In addition, since the third lens group is a shift lens group, it is possible to suppress deterioration in optical performance during lens shift.

In the optical system according to the sixth embodiment of the present application, the third lens group includes a 3a lens group, a 3b lens group, and a 3c lens group in order from the object side. It is desirable that the lens group includes a positive lens and a negative lens. With this configuration, it is possible to satisfactorily correct spherical aberration and coma in the 3a lens group, and it is possible to further improve the performance of the optical system according to the sixth embodiment of the present application. In particular, it is more desirable that the 3a lens group has a positive refractive power.

In the optical system according to the sixth embodiment of the present application, it is desirable that the shift lens group includes a cemented lens of a positive lens and a negative lens and a negative lens in order from the object side. With this configuration, spherical aberration can be favorably corrected in the shift lens group, and spherical aberration and coma aberration can be favorably corrected in the entire third lens group. Thereby, the optical system according to the sixth embodiment of the present application can more effectively suppress the deterioration of the optical performance at the time of lens shift while further improving the performance.

In the optical system according to the sixth embodiment of the present application, the third lens group includes a 3a lens group, a 3b lens group, and a 3c lens group in order from the object side. It is desirable to have an aperture stop on the object side or image side of the lens group. With this configuration, the refractive power arrangement of the optical system according to the sixth embodiment of the present application, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, an aperture stop, By approaching the symmetrical type of the third lens group having positive refractive power, it is possible to satisfactorily correct field curvature and distortion. Thereby, the optical system according to the sixth embodiment of the present application can be further improved in performance.

In the optical system according to the sixth embodiment of the present application, the third lens group includes, in order from the object side, a third a lens group, a third b lens group, and a third c lens group, and the third b It is desirable that the lens group moves as the shift lens group so as to include a component in a direction orthogonal to the optical axis, and satisfies the following conditional expression (6-2).
(6-2) -0.45 <f3a / f3bc <0.40
However,
f3a: focal length of the 3a lens group f3bc: combined focal length of the 3b lens group and the 3c lens group at the time of focusing on an object at infinity

Conditional expression (6-2) defines an appropriate range of the ratio between the focal length of the 3a lens group and the combined focal length of the 3b lens group and the 3c lens group as the shift lens group. The optical system according to the sixth embodiment of the present application can satisfactorily correct the spherical aberration, the coma aberration, and the fluctuation of the coma aberration at the time of lens shift by satisfying the conditional expression (6-2). Thereby, the optical system according to the sixth embodiment of the present application can suppress deterioration in optical performance during lens shift while further improving performance.

When the corresponding value of the conditional expression (6-2) of the optical system according to the sixth embodiment of the present application exceeds the upper limit value, the refractive power of the 3a lens group becomes relatively small, and the 3a lens group alone is generated. Spherical aberration and coma are undercorrected. Further, the refractive powers of the shift lens group and the third c lens group become relatively large. For this reason, fluctuations in coma cannot be suppressed during lens shift, and high optical performance cannot be obtained. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (6-2) to 0.35. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (6-2) to 0.30.

On the other hand, when the corresponding value of the conditional expression (6-2) of the optical system according to the sixth embodiment of the present application is below the lower limit value, the refractive power of the 3a lens group becomes relatively large, and the 3a lens group alone A large amount of spherical aberration and coma occur. Further, the refractive powers of the shift lens group and the third c lens group become relatively small. For this reason, coma is insufficiently corrected during lens shift. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (6-2) to −0.40. In order to further secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (6-2) to −0.35.

In the optical system according to the sixth embodiment of the present application, the first lens group includes a 1a lens group and a 1b lens group in order from the object side, and the 1a lens group and the 1b lens It is desirable that the air gap with the lens group is the largest among the air gaps in the first lens group, and the first lens group has the negative lens closest to the image side. With this configuration, it is possible to suppress the occurrence of spherical aberration in the first lens unit alone, and to correct spherical aberration and coma well in the entire first lens unit. Thereby, the optical system according to the sixth embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

In the optical system according to the sixth embodiment of the present application, the first lens group includes a 1a lens group and a 1b lens group in order from the object side, and the 1a lens group and the 1b lens It is desirable that the air gap with the lens group is the largest of the air gaps in the first lens group, and the following conditional expression (6-3) is satisfied.
(6-3) 1.40 <f1a / f1b <2.05
However,
f1a: focal length of the 1a lens group f1b: focal length of the 1b lens group

Conditional expression (6-3) defines an appropriate range of the focal length ratio of the 1a lens group and the 1b lens group. The optical system according to the sixth embodiment of the present application can satisfactorily correct the spherical aberration and the coma aberration generated in the single lens unit 1a by satisfying conditional expression (6-3). Thereby, the optical system according to the sixth embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

When the corresponding value of the conditional expression (6-3) of the optical system according to the sixth embodiment of the present application exceeds the upper limit value, the refractive power of the 1a lens group becomes relatively small, and the 1a lens group alone is generated. Spherical aberration and coma are undercorrected. In addition, since the refractive power of the first-b lens group becomes relatively large and it becomes impossible to suppress the variation of spherical aberration at the time of focusing, it becomes impossible to obtain high optical performance. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (6-3) to 2.00. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (6-3) to 1.95.

On the other hand, when the corresponding value of the conditional expression (6-3) of the optical system according to the sixth embodiment of the present application is less than the lower limit value, the refractive power of the 1a lens group becomes relatively large, and the 1a lens group alone A large amount of spherical aberration and coma occur. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (6-3) to 1.45. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (6-3) to 1.50.

In the optical system according to the sixth embodiment of the present application, the first lens group includes a 1a lens group and a 1b lens group in order from the object side, and the 1a lens group and the 1b lens The air gap with the lens group is the largest of the air gaps in the first lens group, and the first a lens group is in order from the object side, protective glass, positive lens, positive lens, and negative lens. It is desirable to be composed of With this configuration, spherical aberration can be favorably corrected in the 1a lens group. Thereby, the optical system according to the sixth embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

In the optical system according to the sixth embodiment of the present application, the first lens group includes a 1a lens group and a 1b lens group in order from the object side, and the 1a lens group and the 1b lens An air gap with the lens group is the largest of the air gaps in the first lens group, and the first b lens group includes, in order from the object side, a negative meniscus lens and a positive lens with a convex surface facing the object side. It is desirable that the lens is composed of a cemented lens. With this configuration, it is possible to satisfactorily correct spherical aberration and coma in the 1b lens group. Thereby, the optical system according to the sixth embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

In the optical system according to the sixth embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group. The first a lens group and the first b The air gap with the lens group is the largest of the air gaps in the first lens group, and the first a lens group has at least one positive lens that satisfies the following conditional expression (6-4): It is desirable.
(6-4) 90 <νdp
However,
νdp: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the 1a lens group

Conditional expression (6-4) defines the Abbe number of the glass material of the positive lens in the 1a lens group. The optical system according to the sixth embodiment of the present application can suppress occurrence of longitudinal chromatic aberration and lateral chromatic aberration in the first lens unit alone by satisfying conditional expression (6-4).

When the corresponding value of conditional expression (6-4) of the optical system according to the sixth embodiment of the present application is lower than the lower limit value, axial chromatic aberration and lateral chromatic aberration are greatly generated in the first lens unit alone, and This is not preferable because the optical performance of the optical system according to the embodiment is deteriorated.

In the optical system according to the sixth embodiment of the present application, the second lens group includes a plurality of negative lenses, and the negative lens arranged closest to the image side among the plurality of negative lenses is represented by the following conditional expression: It is desirable to satisfy (6-5).
(6-5) ndn <1.65
However,
ndn: Refractive index with respect to d-line (wavelength: 587.6 nm) of the glass material of the negative lens arranged on the most image side among the plurality of negative lenses in the second lens group

Conditional expression (6-5) defines the refractive index of the glass material of the negative lens disposed closest to the image among the plurality of negative lenses in the second lens group. The optical system according to the sixth embodiment of the present application can satisfy the conditional expression (6-5) and suppress the occurrence of lateral chromatic aberration in the second lens unit alone.

When the corresponding value of the conditional expression (6-5) of the optical system according to the sixth embodiment of the present application exceeds the upper limit value, a large amount of chromatic aberration of magnification occurs in the second lens unit alone, and according to the sixth embodiment of the present application. This is not preferable because the optical performance of the optical system deteriorates.

In the optical system according to the sixth embodiment of the present application, the second lens group includes a plurality of negative lenses, and the negative lens arranged closest to the object among the plurality of negative lenses is represented by the following conditional expression: It is desirable to satisfy (6-6).
(6-6) 49.7 <νdn
However,
νdn: Abbe number with respect to d-line (wavelength: 587.6 nm) of the glass material of the negative lens arranged closest to the object among the plurality of negative lenses in the second lens group

Conditional expression (6-6) defines the Abbe number of the glass material of the negative lens disposed closest to the object among the plurality of negative lenses in the second lens group. The optical system according to the sixth embodiment of the present application can suppress the occurrence of longitudinal chromatic aberration in the second lens unit alone by satisfying conditional expression (6-6).

When the corresponding value of the conditional expression (6-6) of the optical system according to the sixth embodiment of the present application is lower than the lower limit value, axial chromatic aberration is greatly generated in the second lens unit alone, and the sixth embodiment of the present application is applied. Since the optical performance of the optical system is deteriorated, it is not preferable.

Further, it is desirable that the optical system according to the sixth embodiment of the present application satisfies the following conditional expression (6-7).
(6-7) -3.00 <f1 / f2 <-2.00
However,
f1: Focal length of the first lens group f2: Focal length of the second lens group

Conditional expression (6-7) defines an appropriate range of the focal length ratio between the first lens group and the second lens group. The optical system according to the sixth embodiment of the present application satisfies the conditional expression (6-7), thereby suppressing fluctuations in coma during focusing and suppressing occurrence of spherical aberration in the first lens unit alone. be able to. Thereby, the optical system according to the sixth embodiment of the present application can achieve higher performance.

When the corresponding value of the conditional expression (6-7) of the optical system according to the sixth embodiment of the present application exceeds the upper limit value, the refractive power of the first lens group becomes relatively small. For this reason, the first lens group cannot contribute to reducing the tele ratio, that is, the value obtained by dividing the total length of the optical system according to the sixth embodiment of the present application by the focal length, and the optical system according to the sixth embodiment of the present application. The total length of will increase. In addition, since the refractive power of the second lens group becomes relatively large, fluctuations in coma aberration cannot be suppressed during focusing, and high optical performance cannot be obtained. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (6-7) to −2.15. In order to further secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (6-7) to −2.30.

On the other hand, when the corresponding value of the conditional expression (6-7) of the optical system according to the sixth embodiment of the present application is lower than the lower limit value, the refractive power of the first lens group becomes relatively large, and the first lens group alone A large amount of spherical aberration occurs. In addition, the refractive power of the second lens group becomes relatively small, and the amount of movement of the second lens group at the time of focusing becomes great. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (6-7) to −2.85. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (6-7) to −2.70.

In the optical system according to the sixth embodiment of the present application, the second lens group includes, in order from the object side, a negative lens having a concave surface directed toward the image side, and a cemented lens of a positive lens and a negative lens. It is desirable that With this configuration, coma can be favorably corrected in the second lens group. Thereby, the optical system according to the sixth embodiment of the present application can suppress deterioration of the optical performance during focusing while further improving the performance.

In addition, it is desirable that the optical system according to the sixth embodiment of the present application satisfies the following conditional expression (6-8).
(6-8) 0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

Conditional expression (6-8) defines an appropriate range of the ratio between the focal length of the optical system according to the sixth embodiment of the present application and the combined focal length of the first lens group and the second lens group. The optical system according to the sixth embodiment of the present application can satisfactorily correct coma and lateral chromatic aberration generated in the first lens group and the second lens group by satisfying conditional expression (6-8). . Thereby, the optical system according to the sixth embodiment of the present application can achieve higher performance.

When the corresponding value of the conditional expression (6-8) of the optical system according to the sixth embodiment of the present application exceeds the upper limit value, the refractive power of the first lens group and the second lens group becomes relatively large, and the first lens This is not preferable because coma aberration is greatly generated in the first lens group and the second lens group. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (6-8) to 0.55. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (6-8) to 0.53.

On the other hand, when the corresponding value of the conditional expression (6-8) of the optical system according to the sixth embodiment of the present application is below the lower limit value, the refractive powers of the first lens group and the second lens group become relatively small, and the first This is not preferable because the lateral chromatic aberration generated in the first lens group and the second lens group is insufficiently corrected. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (6-8) to 0.20. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (6-8) to 0.30.

The optical apparatus according to the present application includes the optical system according to the sixth embodiment having the above-described configuration. Thereby, it is possible to realize an optical device that corrects various aberrations satisfactorily and suppresses deterioration of optical performance during lens shift.

The optical system manufacturing method according to the sixth embodiment of the present application has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A method of manufacturing an optical system having a third lens group, wherein an antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, The antireflection film includes at least one layer formed by using a wet process, and the second lens group moves along the optical axis when focusing from an object at infinity to a near object, A part of the third lens group moves as a shift lens group so as to include a component in a direction orthogonal to the optical axis, and the optical system satisfies the following conditional expression (6-1): It is characterized by. Accordingly, it is possible to manufacture an optical system that corrects various aberrations satisfactorily and suppresses deterioration of optical performance during lens shift.
(6-1) −1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

Hereinafter, an optical system, an optical device, and an optical system manufacturing method according to the seventh embodiment of the present application will be described.
The optical system according to the seventh embodiment of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. An antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is subjected to a wet process. At least one layer formed by using the lens, and moving the second lens group along the optical axis performs focusing from an object at infinity to an object at a short distance. The following conditional expression (7− 1) is satisfied.
(7-1) 0.10 <f / f12 <0.55
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

As described above, the optical system according to the seventh embodiment of the present application has, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, and the positive refractive power. And a third lens group. With this configuration, the optical system according to the seventh embodiment of the present application can achieve both miniaturization and high performance while having a large focal length.

In addition, as described above, the optical system according to the seventh embodiment of the present application performs focusing from an object at infinity to a near object by moving the second lens group along the optical axis. With this configuration, the second lens group can be driven by a relatively small motor unit.

Conditional expression (7-1) defines the combined refractive power of the first lens group and the second lens group. The optical system according to the seventh embodiment of the present application can satisfactorily correct lateral chromatic aberration by satisfying conditional expression (7-1). Further, the light emitted from the second lens group becomes convergent light. For this reason, the second lens group can be disposed on the image side, and the first lens group can be disposed on the image side accordingly. Accordingly, the entire length of the optical system according to the seventh embodiment of the present application. Can be reduced. In addition, the lateral chromatic aberration can be corrected satisfactorily.

If the corresponding value of conditional expression (7-1) of the optical system according to the seventh embodiment of the present application exceeds the upper limit value, it will be difficult to correct lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-1) to 0.54. In order to further secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-1) to 0.53.

On the other hand, when the corresponding value of the conditional expression (7-1) of the optical system according to the seventh embodiment of the present application is lower than the lower limit value, the light emitted from the second lens group becomes parallel light. The overall length of the optical system according to the embodiment is increased. Therefore, if it is attempted to shorten the overall length of the optical system according to the seventh embodiment of the present application, it will be difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (7-1) to 0.20. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7-1) to 0.30.
With the above configuration, an optical system having a small size and good optical performance can be realized.

Further, in the optical system according to the seventh embodiment of the present application, an antireflection film is provided on at least one of the optical surfaces in the first lens group, the second lens group, and the third lens group, The antireflection film includes at least one layer formed by a wet process. With this configuration, the optical system according to the seventh embodiment of the present application can further reduce ghosts and flares caused by reflection of light from an object on an optical surface, and achieve high imaging performance. it can.

Further, in the optical system according to the seventh embodiment of the present application, the antireflection film is a multilayer film, and the layer formed by using the wet process is the most surface side of the layers constituting the multilayer film. A layer is desirable. With this configuration, the refractive index difference between the layer formed using the wet process and air can be reduced, so that the reflection of light can be further reduced and ghosts and flares can be further reduced. Can do.

Further, in the optical system according to the seventh embodiment of the present application, when the refractive index with respect to d line (wavelength λ = 587.6 nm) of the layer formed by using the wet process is nd, nd is 1.30 or less. It is desirable that With this configuration, the refractive index difference between the layer formed using the wet process and air can be reduced, so that the reflection of light can be further reduced and ghosts and flares can be further reduced. Can do.

In the optical system according to the seventh embodiment of the present application, it is preferable that the optical surface provided with the antireflection film is a concave lens surface when viewed from the image surface side. Of the optical surfaces in the first lens group, the second lens group, and the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image plane side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the seventh embodiment of the present application, it is desirable that the concave lens surface when viewed from the image surface side is an image surface side lens surface of a lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the seventh embodiment of the present application, it is desirable that the concave lens surface when viewed from the image surface side is an image surface side lens surface of a lens in the second lens group. Of the optical surfaces in the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the seventh embodiment of the present application, it is preferable that the concave lens surface viewed from the image surface side is an object side lens surface of a lens in the third lens group. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the seventh embodiment of the present application, it is desirable that the concave lens surface when viewed from the image surface side be an image surface side lens surface of a lens in the third lens group. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the seventh embodiment of the present application, the concave lens surface viewed from the image surface side is the image surface side lens surface of the fourth lens from the object side in the third lens group. It is desirable. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the seventh embodiment of the present application, it is preferable that the optical surface provided with the antireflection film is a concave lens surface when viewed from the object side. Of the optical surfaces in the first lens group and the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the seventh embodiment of the present application, it is desirable that the concave lens surface when viewed from the object side is an object side lens surface of the lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the seventh embodiment of the present application, it is desirable that the concave lens surface viewed from the object side is an image surface side lens surface of the lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the seventh embodiment of the present application, it is desirable that the concave lens surface viewed from the object side is an object side lens surface of the lens in the second lens group. Of the optical surfaces in the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

The antireflection film in the optical system according to the seventh embodiment of the present application is not limited to a wet process, and may be formed by a dry process or the like. In this case, the antireflection film preferably includes at least one layer having a refractive index of 1.30 or less. With this configuration, even when the antireflection film is formed by a dry process or the like, the same effect as when the antireflection film is formed by a wet process can be obtained. Note that the layer having a refractive index of 1.30 or less is preferably the outermost layer among the layers constituting the multilayer film.

In the optical system according to the seventh embodiment of the present application, it is preferable that the first lens group has at least one positive lens that satisfies the following conditional expression (7-2).
(7-2) 80 <νd1p <110
However,
νd1p: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the first lens group

Conditional expression (7-2) defines the Abbe number of the glass material of the positive lens in the first lens group. The optical system according to the seventh embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (7-2).

If the corresponding value of conditional expression (7-2) of the optical system according to the seventh embodiment of the present application exceeds the upper limit value, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-2) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-2) to 100.

On the other hand, if the corresponding value of the conditional expression (7-2) of the optical system according to the seventh embodiment of the present application is less than the lower limit value, it will be difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7-2) to 85. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7-2) to 90.

Further, in the optical system according to the seventh embodiment of the present application, the first lens group includes a plurality of positive lenses, and the positive lens arranged closest to the object among the plurality of positive lenses is represented by the following conditional expression: It is desirable to satisfy (7-3).
(7-3) 80 <νd1pf <110
However,
νd1pf: Abbe number with respect to the d-line (wavelength 587.6 nm) of the glass material of the positive lens arranged closest to the object side among the plurality of positive lenses in the first lens group

Conditional expression (7-3) defines the Abbe number of the glass material of the positive lens disposed closest to the object among the plurality of positive lenses in the first lens group. The optical system according to the seventh embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (7-3).

If the corresponding value of the conditional expression (7-3) of the optical system according to the seventh embodiment of the present application exceeds the upper limit value, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-3) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-3) to 100.

On the other hand, if the corresponding value of the conditional expression (7-3) of the optical system according to the seventh embodiment of the present application is lower than the lower limit value, it will be difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (7-3) to 85. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7-3) to 90.

In the optical system according to the seventh embodiment of the present application, it is preferable that the first lens group has at least one negative lens satisfying the following conditional expression (7-4).
(7-4) 1.50 <nd1n <1.75
However,
nd1n: refractive index with respect to d-line (wavelength 587.6 nm) of the glass material of the negative lens in the first lens group

Conditional expression (7-4) defines the refractive index of the glass material of the negative lens in the first lens group. By satisfying conditional expression (7-4), the optical system according to the seventh embodiment of the present application can favorably correct coma and curvature of field while reducing the weight.

When the corresponding value of the conditional expression (7-4) of the optical system according to the seventh embodiment of the present application exceeds the upper limit value, the specific gravity of the glass material of the negative lens in the first lens group increases. Therefore, if the specific gravity of other lenses in the first lens group is reduced in order to reduce the weight of the optical system according to the seventh embodiment of the present application, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (7-4) to 1.70. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-4) to 1.65.

On the other hand, if the corresponding value of the conditional expression (7-4) of the optical system according to the seventh embodiment of the present application is lower than the lower limit value, it becomes difficult to correct the curvature of field. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (7-4) to 1.55. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (7-4) to 1.60.

In addition, in the optical system according to the seventh embodiment of the present application, it is preferable that at least a part of the third lens group moves so as to include a component in a direction orthogonal to the optical axis. With this configuration, image blur due to camera shake or the like can be corrected, that is, image stabilization can be performed, and the occurrence of decentration aberrations during image stabilization can be suppressed to a level where there is no problem.

In the optical system according to the seventh embodiment of the present application, the third lens group includes, in order from the object side, a 3a lens group having a positive refractive power, a 3b lens group having a negative refractive power, It is desirable that the third lens unit is composed of a third lens unit having positive refractive power, and the third lens unit moves so as to include a component in a direction orthogonal to the optical axis. With this configuration, image blur due to camera shake or the like can be corrected, that is, image stabilization can be performed, and the occurrence of decentration aberrations during image stabilization can be suppressed to a level where there is no problem. In addition, since the diameter of the 3b lens group can be reduced, the mechanical unit for driving the 3b lens group during vibration isolation can be reduced in size.

In the optical system according to the seventh embodiment of the present application, it is preferable that the first lens group includes a cemented lens of a negative lens and a positive lens in order from the object side. With this configuration, the decentration aberration can be corrected satisfactorily. The cemented lens is more preferably arranged on the most image side in the first lens group.

In the optical system according to the seventh embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b It is desirable that the air gap with the lens group is the largest of the air gaps in the first lens group and the following conditional expression (7-5) is satisfied.
(7-5) 0.30 <TL1a / TL1 <0.70
However,
TL1a: length along the optical axis of the first lens group TL1: length along the optical axis of the first lens group

Conditional expression (7-5) defines the length of the first lens group with respect to the length of the first lens group. The optical system according to the seventh embodiment of the present application can satisfactorily correct the coma aberration while reducing the weight by satisfying conditional expression (7-5).

When the corresponding value of the conditional expression (7-5) of the optical system according to the seventh embodiment of the present application exceeds the upper limit value, the weight of the first lens group increases. Therefore, for example, if a glass material having a small refractive index is used for the negative lens in the first lens group in order to reduce the weight, it becomes difficult to correct curvature of field. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-5) to 0.60. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (7-5) to 0.50.

On the other hand, when the corresponding value of the conditional expression (7-5) of the optical system according to the seventh embodiment of the present application is less than the lower limit value, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7-5) to 0.35. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (7-5) to 0.40.

In the optical system according to the seventh embodiment of the present application, it is preferable that the 1a lens group includes a positive lens, a positive lens, and a negative lens in order from the object side. With this configuration, it is possible to reduce the weight of the optical system according to the seventh embodiment of the present application.
In the optical system according to the seventh embodiment of the present application, it is preferable that the first lens group has a protective filter glass on the most object side. The protective filter glass is a lens having substantially no refractive power, and the focal length thereof is preferably 10 times or more the focal length of the optical system according to the seventh embodiment of the present application. In particular, the optical system according to the seventh embodiment of the present application preferably has a negative meniscus shape in which the protective filter glass has a convex surface facing the object side. With this configuration, the ghost can be cut well.
In the optical system according to the seventh embodiment of the present application, it is preferable that the first-b lens group includes a negative lens and a positive lens in order from the object side. With this configuration, it is possible to satisfactorily correct variations in spherical aberration when focusing on a short-distance object. In particular, in the optical system according to the seventh embodiment of the present application, it is preferable that the first b lens group includes only a cemented lens of a negative lens and a positive lens in order from the object side. With this configuration, it is possible to reduce the weight of the optical system according to the seventh embodiment of the present application.

In the optical system according to the seventh embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a 1b lens group, and the first a lens group and the first b It is desirable that the air gap with the lens group is the largest of the air gaps in the first lens group, and the first b lens group has a positive lens that satisfies the following conditional expression (7-6). .
(7-6) 70 <νd1bp <110
However,
νd1bp: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the 1b lens group

Conditional expression (7-6) defines the Abbe number of the glass material of the positive lens in the 1b lens group. The optical system according to the seventh embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (7-6).

If the corresponding value of the conditional expression (7-6) of the optical system according to the seventh embodiment of the present application exceeds the upper limit, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-6) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-6) to 100.

On the other hand, if the corresponding value of the conditional expression (7-6) of the optical system according to the seventh embodiment of the present application is lower than the lower limit value, it is difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7-6) to 75. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7-6) to 80.

In the optical system according to the seventh embodiment of the present application, it is desirable that the second lens group has two negative lens components. With this configuration, coma can be corrected well. Here, in the seventh embodiment of the present application, the “lens component” refers to a cemented lens or a single lens formed by cementing two or more lenses.
In the optical system according to the seventh embodiment of the present application, the second lens group may include a negative lens, a positive lens, and a negative lens in order from the object side. The second lens group may include a positive lens, a negative lens, and a negative lens in order from the object side. With these configurations, coma can be corrected well.

In the optical system according to the seventh embodiment of the present application, it is preferable that the second lens group includes a positive lens that satisfies the following conditional expression (7-7).
(7-7) 15 <νd2p <30
However,
νd2p: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the second lens group

Conditional expression (7-7) defines the Abbe number of the glass material of the positive lens in the second lens group. The optical system according to the seventh embodiment of the present application can satisfactorily correct lateral chromatic aberration and axial chromatic aberration by satisfying conditional expression (7-7).

If the corresponding value of the conditional expression (7-7) of the optical system according to the seventh embodiment of the present application exceeds the upper limit value, it will be difficult to correct lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-7) to 27. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (7-7) to 25.

On the other hand, when the corresponding value of the conditional expression (7-7) of the optical system according to the seventh embodiment of the present application is lower than the lower limit value, in order to prevent the transmittance of light having a short wavelength from decreasing, However, it becomes impossible to use a lens made of a glass material having a large dispersion in the lens group located on the image side. This makes it difficult to correct axial chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (7-7) to 16. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (7-7) to 17.

The optical apparatus according to the present application includes the optical system according to the seventh embodiment having the above-described configuration. Thereby, an optical device having a small size and good optical performance can be realized.

The optical system manufacturing method according to the seventh embodiment of the present application has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A method of manufacturing an optical system having a third lens group, wherein an antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, The antireflection film includes at least one layer formed by a wet process, the optical system satisfies the following conditional expression (7-1), and the second lens group is moved along the optical axis. It is characterized in that focusing from an object at infinity to a near object is performed by moving the object. Thereby, an optical system having a small size and good optical performance can be manufactured.
(7-1) 0.10 <f / f12 <0.55
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

Next, an optical system, an optical device, and an optical system manufacturing method according to the eighth embodiment of the present application will be described.
The optical system according to the eighth embodiment of the present application includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. An antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is subjected to a wet process. Including at least one layer formed by using the second lens group to move from the object at infinity to the near object by moving the second lens group along the optical axis. It has at least three lenses and satisfies the following conditional expression (8-1).
(8-1) 0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

As described above, the optical system according to the eighth embodiment of the present application includes, in order from the object side, the first lens group having a positive refractive power, the second lens group having a negative refractive power, and the positive refractive power. And a third lens group. With this configuration, the optical system according to the eighth embodiment of the present application can achieve both miniaturization and high performance while having a large focal length.

Further, as described above, the optical system according to the eighth embodiment of the present application performs focusing from an infinitely distant object to a close object by moving the second lens group along the optical axis. With this configuration, the second lens group can be driven by a relatively small motor unit.
As described above, in the optical system according to the eighth embodiment of the present application, the second lens group includes at least three lenses. With this configuration, coma can be corrected well.

Conditional expression (8-1) defines the combined refractive power of the first lens group and the second lens group. The optical system according to the eighth embodiment of the present application can satisfactorily correct lateral chromatic aberration by satisfying conditional expression (8-1). Further, the light emitted from the second lens group becomes convergent light. For this reason, since the second lens group can be arranged on the image side, and the first lens group can be arranged on the image side accordingly, the entire length of the optical system according to the eighth embodiment of the present application. Can be reduced. In addition, the lateral chromatic aberration can be corrected satisfactorily.

If the corresponding value of conditional expression (8-1) of the optical system according to the eighth embodiment of the present application exceeds the upper limit value, it will be difficult to correct lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (8-1) to 0.80. In order to further secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-1) to 0.75.

On the other hand, when the corresponding value of the conditional expression (8-1) of the optical system according to the eighth embodiment of the present application is less than the lower limit value, the light emitted from the second lens group becomes parallel light. The overall length of the optical system according to the embodiment is increased. Therefore, if it is attempted to shorten the overall length of the optical system according to the eighth embodiment of the present application, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (8-1) to 0.20. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (8-1) to 0.30.
With the above configuration, an optical system having a small size and good optical performance can be realized.

In the optical system according to the eighth embodiment of the present application, an antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, The antireflection film includes at least one layer formed by a wet process. With this configuration, the optical system according to the eighth embodiment of the present application can further reduce ghosts and flares caused by reflection of light from an object on an optical surface, and achieve high imaging performance. it can.

Further, in the optical system according to the eighth embodiment of the present application, the antireflection film is a multilayer film, and the layer formed by using the wet process is the most surface side of the layers constituting the multilayer film. A layer is desirable. With this configuration, the refractive index difference between the layer formed using the wet process and air can be reduced, so that the reflection of light can be further reduced and ghosts and flares can be further reduced. Can do.

Further, in the optical system according to the eighth embodiment of the present application, when the refractive index with respect to d line (wavelength λ = 587.6 nm) of the layer formed by using the wet process is nd, nd is 1.30 or less. It is desirable that With this configuration, the refractive index difference between the layer formed using the wet process and air can be reduced, so that the reflection of light can be further reduced and ghosts and flares can be further reduced. Can do.

In the optical system according to the eighth embodiment of the present application, it is preferable that the optical surface provided with the antireflection film is a concave lens surface when viewed from the image surface side. Of the optical surfaces in the first lens group, the second lens group, and the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image plane side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the eighth embodiment of the present application, it is desirable that the concave lens surface when viewed from the image surface side be an image surface side lens surface of a lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the eighth embodiment of the present application, it is preferable that the concave lens surface viewed from the image surface side is an image surface side lens surface of a lens in the second lens group. Of the optical surfaces in the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the eighth embodiment of the present application, it is preferable that the concave lens surface viewed from the image surface side be an object side lens surface of a lens in the third lens group. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the eighth embodiment of the present application, it is preferable that the concave lens surface viewed from the image surface side be an image surface side lens surface of a lens in the third lens group. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the eighth embodiment of the present application, the concave lens surface viewed from the image surface side is the image surface side lens surface of the fourth lens from the object side in the third lens group. It is desirable. Of the optical surfaces in the third lens group, reflected light tends to be generated on a concave lens surface as viewed from the image surface side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the eighth embodiment of the present application, it is preferable that the optical surface provided with the antireflection film is a concave lens surface when viewed from the object side. Of the optical surfaces in the first lens group and the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the eighth embodiment of the present application, it is preferable that the concave lens surface viewed from the object side is an object side lens surface of the lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the eighth embodiment of the present application, it is preferable that the concave lens surface viewed from the object side is an image surface side lens surface of a lens in the first lens group. Of the optical surfaces in the first lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

In the optical system according to the eighth embodiment of the present application, it is preferable that the concave lens surface viewed from the object side is an object side lens surface of a lens in the second lens group. Of the optical surfaces in the second lens group, reflected light tends to be generated on a concave lens surface as viewed from the object side. For this reason, a ghost and flare can be effectively reduced by forming an antireflection film on such a lens surface.

Note that the antireflection film in the optical system according to the eighth embodiment of the present application is not limited to a wet process, and may be formed by a dry process or the like. In this case, the antireflection film preferably includes at least one layer having a refractive index of 1.30 or less. With this configuration, even when the antireflection film is formed by a dry process or the like, the same effect as when the antireflection film is formed by a wet process can be obtained. Note that the layer having a refractive index of 1.30 or less is preferably the outermost layer among the layers constituting the multilayer film.

In the optical system according to the eighth embodiment of the present application, it is preferable that at least two of the at least three lenses in the second lens group are negative lenses. With this configuration, coma can be corrected well.
In the optical system according to the eighth embodiment of the present application, the second lens group includes a negative lens, a positive lens, and a negative lens in order from the object side, or a positive lens in order from the object side. And a negative lens and a negative lens are more preferable. In these configurations, it is most preferable to join a positive lens and a negative lens. With the above configuration, coma aberration can be corrected more favorably.

In the optical system according to the eighth embodiment of the present application, it is preferable that the second lens group includes at least one negative lens that satisfies the following conditional expression (8-2).
(8-2) 1.45 <nd2n <1.65
However,
nd2n: refractive index with respect to d-line (wavelength 587.6 nm) of the glass material of the negative lens in the second lens group

Conditional expression (8-2) defines the refractive index of the glass material of the negative lens in the second lens group. By satisfying conditional expression (8-2), the optical system according to the eighth embodiment of the present application achieves good coma and curvature of field while reducing the weight of the second lens group that is the focusing lens group. Can be corrected.

When the corresponding value of the conditional expression (8-2) of the optical system according to the eighth embodiment of the present application exceeds the upper limit value, the specific gravity of the glass material of the negative lens in the second lens group increases. Therefore, if the specific gravity of other lenses in the second lens group is reduced in order to reduce the weight of the optical system according to the eighth embodiment of the present application, it will be difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-2) to 1.64. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (8-2) to 1.63.

On the other hand, if the corresponding value of the conditional expression (8-2) of the optical system according to the eighth embodiment of the present application is less than the lower limit value, it becomes difficult to correct the curvature of field. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-2) to 1.48. In order to further secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (8-2) to 1.50.

In the optical system according to the eighth embodiment of the present application, it is preferable that the second lens group includes a positive lens that satisfies the following conditional expression (8-3).
(8-3) 15 <νd2p <30
However,
νd2p: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the second lens group

Conditional expression (8-3) defines the Abbe number of the glass material of the positive lens in the second lens group. The optical system according to the eighth embodiment of the present application can satisfactorily correct lateral chromatic aberration and axial chromatic aberration by satisfying conditional expression (8-3).

If the corresponding value of the conditional expression (8-3) of the optical system according to the eighth embodiment of the present application exceeds the upper limit value, it will be difficult to correct lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (8-3) to 27. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-3) to 25.

On the other hand, when the corresponding value of the conditional expression (8-3) of the optical system according to the eighth embodiment of the present application is less than the lower limit value, in order to prevent the transmittance of light having a short wavelength from decreasing, However, it becomes impossible to use a lens made of a glass material having a large dispersion in the lens group located on the image side. This makes it difficult to correct axial chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (8-3) to 16. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-3) to 17.

In the optical system according to the eighth embodiment of the present application, it is desirable that the first lens group has at least one positive lens that satisfies the following conditional expression (8-4).
(8-4) 80 <νd1p <110
However,
νd1p: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the first lens group

Conditional expression (8-4) defines the Abbe number of the glass material of the positive lens in the first lens group. The optical system according to the eighth embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (8-4).

If the corresponding value of the conditional expression (8-4) of the optical system according to the eighth embodiment of the present application exceeds the upper limit value, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit value of conditional expression (8-4) to 105. In order to further secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-4) to 100.

On the other hand, if the corresponding value of the conditional expression (8-4) of the optical system according to the eighth embodiment of the present application is less than the lower limit value, it will be difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-4) to 85. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-4) to 90.

In the optical system according to the eighth embodiment of the present application, the first lens group includes a plurality of positive lenses, and the positive lens arranged closest to the object among the plurality of positive lenses is represented by the following conditional expression: It is desirable to satisfy (8-5).
(8-5) 80 <νd1pf <110
However,
νd1pf: Abbe number with respect to the d-line (wavelength 587.6 nm) of the glass material of the positive lens arranged closest to the object side among the plurality of positive lenses in the first lens group

Conditional expression (8-5) defines the Abbe number of the glass material of the positive lens disposed closest to the object among the plurality of positive lenses in the first lens group. The optical system according to the eighth embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (8-5).

If the corresponding value of the conditional expression (8-5) of the optical system according to the eighth embodiment of the present application exceeds the upper limit value, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-5) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-5) to 100.

On the other hand, when the corresponding value of the conditional expression (8-5) of the optical system according to the eighth embodiment of the present application is lower than the lower limit value, it becomes difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-5) to 85. In order to further secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-5) to 90.

In the optical system according to the eighth embodiment of the present application, it is preferable that the first lens group has at least one negative lens satisfying the following conditional expression (8-6).
(8-6) 1.50 <nd1n <1.75
However,
nd1n: refractive index with respect to d-line (wavelength 587.6 nm) of the glass material of the negative lens in the first lens group

Conditional expression (8-6) defines the refractive index of the glass material of the negative lens in the first lens group. The optical system according to the eighth embodiment of the present application can satisfactorily correct coma and curvature of field while reducing the weight by satisfying conditional expression (8-6).

When the corresponding value of the conditional expression (8-6) of the optical system according to the eighth embodiment of the present application exceeds the upper limit value, the specific gravity of the glass material of the negative lens in the first lens group increases. Therefore, if the specific gravity of other lenses in the first lens group is reduced in order to reduce the weight of the optical system according to the eighth embodiment of the present application, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-6) to 1.70. In order to further secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-6) to 1.65.

On the other hand, when the corresponding value of the conditional expression (8-6) of the optical system according to the eighth embodiment of the present application is less than the lower limit value, it becomes difficult to correct the curvature of field. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (8-6) to 1.55. In order to secure the effect of the present application, it is more preferable to set the lower limit value of conditional expression (8-6) to 1.60.

In addition, in the optical system according to the eighth embodiment of the present application, it is preferable that at least a part of the third lens group moves so as to include a component in a direction orthogonal to the optical axis. With this configuration, image blur due to camera shake or the like can be corrected, that is, image stabilization can be performed, and the occurrence of decentration aberrations during image stabilization can be suppressed to a level where there is no problem.

Further, in the optical system according to the eighth embodiment of the present application, the third lens group includes, in order from the object side, a 3a lens group having a positive refractive power, a 3b lens group having a negative refractive power, It is desirable that the third lens unit is composed of a third lens unit having positive refractive power, and the third lens unit moves so as to include a component in a direction orthogonal to the optical axis. With this configuration, image blur due to camera shake or the like can be corrected, that is, image stabilization can be performed, and the occurrence of decentration aberrations during image stabilization can be suppressed to a level where there is no problem. In addition, since the diameter of the 3b lens group can be reduced, the mechanical unit for driving the 3b lens group during vibration isolation can be reduced in size.

In the optical system according to the eighth embodiment of the present application, it is preferable that the first lens group includes a cemented lens of a negative lens and a positive lens in order from the object side. With this configuration, the decentration aberration can be corrected satisfactorily. The cemented lens is more preferably arranged on the most image side in the first lens group.

In the optical system according to the eighth embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a first b lens group. The first a lens group and the first b It is desirable that the air gap with the lens group is the largest among the air gaps in the first lens group, and the following conditional expression (8-7) is satisfied.
(8-7) 0.30 <TL1a / TL1 <0.70
However,
TL1a: length along the optical axis of the first lens group TL1: length along the optical axis of the first lens group

Conditional expression (8-7) defines the length of the first lens group with respect to the length of the first lens group. By satisfying conditional expression (8-7), the optical system according to the eighth embodiment of the present application can correct coma favorably while achieving weight reduction.

When the corresponding value of the conditional expression (8-7) of the optical system according to the eighth embodiment of the present application exceeds the upper limit value, the weight of the first lens group increases. Therefore, for example, if a glass material having a small refractive index is used for the negative lens in the first lens group in order to reduce the weight, it becomes difficult to correct curvature of field. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-7) to 0.60. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-7) to 0.50.

On the other hand, when the corresponding value of the conditional expression (8-7) of the optical system according to the eighth embodiment of the present application is less than the lower limit value, it becomes difficult to correct coma. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-7) to 0.35. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-7) to 0.40.

In the optical system according to the eighth embodiment of the present application, it is preferable that the first-a lens group includes a positive lens, a positive lens, and a negative lens in order from the object side. With this configuration, it is possible to reduce the weight of the optical system according to the eighth embodiment of the present application.

In the optical system according to the eighth embodiment of the present application, it is preferable that the first lens group has a protective filter glass on the most object side. The protective filter glass is a lens having substantially no refractive power, and its focal length is preferably 10 times or more of the focal length of the optical system according to the eighth embodiment of the present application. In particular, the optical system according to the eighth embodiment of the present application preferably has a negative meniscus shape in which the protective filter glass has a convex surface facing the object side. With this configuration, the ghost can be cut well.

In the optical system according to the eighth embodiment of the present application, it is preferable that the first-b lens group includes a negative lens and a positive lens in order from the object side. With this configuration, it is possible to satisfactorily correct variations in spherical aberration when focusing on a short-distance object. In particular, in the optical system according to the eighth embodiment of the present application, it is preferable that the 1b lens group includes only a cemented lens of a negative lens and a positive lens in order from the object side. With this configuration, it is possible to reduce the weight of the optical system according to the eighth embodiment of the present application.

In the optical system according to the eighth embodiment of the present application, the first lens group includes, in order from the object side, a first a lens group and a first b lens group. The first a lens group and the first b It is desirable that the air gap with the lens group is the largest of the air gaps in the first lens group, and the first b lens group has a positive lens that satisfies the following conditional expression (8-8). .
(8-8) 70 <νd1bp <110
However,
νd1bp: Abbe number with respect to d-line (wavelength 587.6 nm) of the glass material of the positive lens in the 1b lens group

Conditional expression (8-8) defines the Abbe number of the glass material of the positive lens in the 1b lens group. The optical system according to the eighth embodiment of the present application can satisfactorily correct axial chromatic aberration and lateral chromatic aberration by satisfying conditional expression (8-8).

If the corresponding value of the conditional expression (8-8) of the optical system according to the eighth embodiment of the present application exceeds the upper limit value, it is not preferable because axial chromatic aberration and lateral chromatic aberration are excessively corrected. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-8) to 105. In order to secure the effect of the present application, it is more preferable to set the upper limit of conditional expression (8-8) to 100.

On the other hand, when the corresponding value of the conditional expression (8-8) of the optical system according to the eighth embodiment of the present application is lower than the lower limit value, it becomes difficult to correct axial chromatic aberration and lateral chromatic aberration. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-8) to 75. In order to secure the effect of the present application, it is more preferable to set the lower limit of conditional expression (8-8) to 80.

The optical apparatus according to the present application includes the optical system according to the eighth embodiment having the above-described configuration. Thereby, an optical device having a small size and good optical performance can be realized.

The optical system manufacturing method according to the eighth embodiment of the present application has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power. A method of manufacturing an optical system having a third lens group, wherein an antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, The antireflection film includes at least one layer formed by a wet process, the second lens group includes at least three lenses, and the optical system has the following conditional expression (8-1) And the second lens group is moved along the optical axis to focus from an object at infinity to an object at close distance. Thereby, an optical system having a small size and good optical performance can be manufactured.
(8-1) 0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity

Hereinafter, optical systems according to numerical examples of the first to eighth embodiments of the present application will be described with reference to the accompanying drawings. The first to sixth examples are examples common to the first to eighth embodiments, and the seventh to ninth examples are examples common to the third to sixth embodiments.
(First embodiment)
FIG. 1 is a sectional view showing a lens arrangement at the time of focusing on an object at infinity in an optical system according to a first example common to the first to eighth embodiments of the present application.
The optical system according to this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. And G3. An aperture stop S is provided between the second lens group G2 and the third lens group G3, and a filter FL is provided between the third lens group G3 and the image plane I.

The first lens group G1 includes, in order from the object side, a first a lens group G1a having a positive refractive power and a first b lens group G1b having a positive refractive power.
The first-a lens group G1a includes, in order from the object side, a protective filter glass FLG, a biconvex positive lens L11, a biconvex positive lens L12, and a biconcave negative lens L13. The protective filter glass FLG has a negative meniscus shape with a convex surface facing the object side, and has substantially no refractive power.
The first-b lens group G1b includes, in order from the object side, a cemented lens of a negative meniscus lens L14 having a convex surface facing the object side and a positive meniscus lens L15 having a convex surface facing the object side.

The second lens group G2 includes, in order from the object side, a biconcave negative lens L21, and a cemented negative lens of a positive meniscus lens L22 having a concave surface facing the object side and a biconcave negative lens L23.

The third lens group G3 includes, in order from the object side, a third a lens group G3a having a positive refractive power, a third b lens group G3b having a negative refractive power, and a third c lens group G3c having a positive refractive power. It is composed of
The third-a lens group G3a is composed of, in order from the object side, a biconvex positive lens L31 and a negative meniscus lens L32 having a concave surface facing the object side.
The third-b lens group G3b includes, in order from the object side, a cemented lens of a biconvex positive lens L33 and a biconcave negative lens L34, and a biconcave negative lens L35.
The third c lens group G3c includes, in order from the object side, a biconvex positive lens L36, and a cemented lens of a biconvex positive lens L37 and a biconcave negative lens L38.

The optical system according to this example includes an object of the image side lens surface (surface number 24) of the biconcave negative lens L34 of the third lens group G3 and the biconvex positive lens L36 of the third lens group G3. An antireflection film described later is formed on the side lens surface (surface number 27).

Under the above configuration, in the optical system according to the present embodiment, the second lens group G2 is moved to the image side along the optical axis, thereby focusing from an object at infinity to a near object. Note that the position of the aperture stop S is fixed with respect to the image plane I during focusing. In addition, the shooting distance of the optical system according to the present embodiment when focusing on a short-distance object is 2.6 m.
In the optical system according to the present embodiment, the third lens group G3b in the third lens group G3 is shifted so as to include a component in a direction orthogonal to the optical axis as a shift lens group, that is, an anti-vibration lens group. .
On the image plane I, an image sensor (not shown) constituted by a CCD, a CMOS, or the like is disposed. The same applies to each embodiment described later.

Table 1 below lists values of specifications of the optical system according to the present example.
In Table 1, f indicates the focal length, and Bf indicates the back focus, that is, the distance on the optical axis between the filter FL and the image plane I.
In [Surface data], m is the order of the optical surfaces counted from the object side, r is the radius of curvature, d is the surface spacing (the space between the nth surface (n is an integer) and the (n + 1) th surface), and nd is d. The refractive index for the line (wavelength 587.6 nm) and νd indicate the Abbe number for the d line (wavelength 587.6 nm), respectively. Further, OP represents the object plane, variable represents the variable surface interval, S represents the aperture stop S, and I represents the image plane I. The radius of curvature r = ∞ indicates a plane. Further, the description of the refractive index nd of air = 1.0000 is omitted.

In [various data], FNO is the F number, 2ω is the angle of view (unit is “°”), Y is the image height, TL is the total length of the optical system according to the present embodiment, that is, from the first surface to the image surface I. A distance on the optical axis, dn, indicates a variable distance between the nth surface and the (n + 1) th surface. Here, β represents the photographing magnification, and d0 represents the distance from the object to the first surface.
[Lens Group Data] indicates the start surface ST and focal length f of each lens group.
[Conditional Expression Corresponding Value] indicates the corresponding value of each conditional expression of the optical system according to the present example.

Here, the focal length f, the radius of curvature r, and other length units listed in Table 1 are generally “mm”. However, the optical system is not limited to this because an equivalent optical performance can be obtained even when proportionally enlarged or proportionally reduced.
In addition, the code | symbol of Table 1 described above shall be similarly used also in the table | surface of each Example mentioned later.

(Table 1) First Example
[Surface data]
m r d nd νd
OP ∞ ∞

1 1200.3704 5.00 1.51680 63.88
2 1199.7897 1.00
3 208.5821 17.50 1.43385 95.25
4 -1176.6338 45.00
5 180.4147 18.00 1.43385 95.25
6 -380.1711 3.00
7 -348.9527 6.00 1.61266 44.46
8 384.9936 90.00
9 67.5463 4.00 1.79500 45.31
10 46.6351 15.00 1.49782 82.57
11 1089.9704 Variable
12 -1616.0869 2.50 1.77250 49.62
13 118.0496 3.35
14 -285.3999 3.50 1.84666 23.80
15 -87.3702 2.40 1.51823 58.82
16 63.6357 Variable
17 (S) ∞ 2.00

18 84.6009 8.00 1.48749 70.31
19 -63.3175 0.60
20 -66.2548 1.90 1.84666 23.80
21 -116.1778 5.00
22 433.7902 3.50 1.84666 23.80
23 -123.0826 1.90 1.59319 67.90
24 51.3275 3.60
25 -293.4310 1.90 1.75500 52.34
26 110.9976 4.00
27 130.2260 3.50 1.77250 49.62
28 -326.0207 0.10
29 67.6197 4.50 1.64000 60.20
30 -391.1361 1.90 1.84666 23.80
31 276.0025 9.00

32 ∞ 2.00 1.51680 63.88
33 ∞ Bf

I ∞

[Various data]
f 392.00
FNO 2.88
2ω 6.27
Y 21.60
TL 396.95
Bf 71.551

When focusing on an object at infinity When focusing on a near object f or β 392.003 -0.173
d0 ∞ 2201.931
d11 19.530 34.930
d16 36.219 20.820
Bf 71.551 71.575

[Lens group data]
ST f
G1 1 179.9884
G2 12 -67.9431
G3 18 163.6612

[Conditional expression values]
fF = 322.0136
fR = -760.8459
f = 392.0028
f1 = 179.9884
f1a = 355.6752
f1b = 194.3600
f2 = -67.9431
f12 = 1030.4247
f3a = 125.9727
f3bc = -760.8459
νdp = 95.25 (L11), 95.25 (L12)
ndn = 1.51823
νdn = 58.82
βs = -4.8884
βr = −0.2490

(First embodiment)
(1-1) f / f12 = 0.38
(1-2) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(1-3) νd1pf = 95.25
(1-4) nd1n = 1.61
(1-5) TL1a / TL1 = 0.47
(1-6) νd1bp = 82.57
(1-7) νd2p = 23.80

(Second Embodiment)
(2-1) f / f12 = 0.38
(2-2) nd2n = 1.52
(2-3) νd2p = 23.80
(2-4) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(2-5) νd1pf = 95.25
(2-6) nd1n = 1.61
(2-7) TL1a / TL1 = 0.47
(2-8) νd1bp = 82.57

(Third embodiment)
(3-1) βr × (1-βs) = − 1.4664
(3-2) f3a / f3bc = -0.1656
(3-3) f1a / f1b = 1.8300
(3-4) νdp = 95.25 (L11), 95.25 (L12)
(3-5) ndn = 1.51823
(3-6) νdn = 58.82
(3-7) f1 / f2 = -2.6491
(3-8) f / f12 = 0.3804

(Fourth embodiment)
(4-1) | fR / fF | = 2.3628
(4-2) βr × (1-βs) = − 1.4664
(4-3) f3a / f3bc = -0.1656
(4-4) f1a / f1b = 1.8300
(4-5) νdp = 95.25 (L11), 95.25 (L12)
(4-6) ndn = 1.51823
(4-7) νdn = 58.82
(4-8) f1 / f2 = -2.6491
(4-9) f / f12 = 0.3804

(Fifth embodiment)
(5-1) | fR / fF | = 2.3628
(5-2) βr × (1-βs) = − 1.4664
(5-3) f3a / f3bc = -0.1656
(5-4) f1a / f1b = 1.8300
(5-5) νdp = 95.25 (L11), 95.25 (L12)
(5-6) ndn = 1.51823
(5-7) νdn = 58.82
(5-8) f1 / f2 = -2.6491
(5-9) f / f12 = 0.3804

(Sixth embodiment)
(6-1) βr × (1-βs) = − 1.4664
(6-2) f3a / f3bc = -0.1656
(6-3) f1a / f1b = 1.8300
(6-4) νdp = 95.25 (L11), 95.25 (L12)
(6-5) ndn = 1.51823
(6-6) νdn = 58.82
(6-7) f1 / f2 = -2.6491
(6-8) f / f12 = 0.3804

(Seventh embodiment)
(7-1) f / f12 = 0.38
(7-2) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(7-3) νd1pf = 95.25
(7-4) nd1n = 1.61
(7-5) TL1a / TL1 = 0.47
(7-6) νd1bp = 82.57
(7-7) νd2p = 23.80

(Eighth embodiment)
(8-1) f / f12 = 0.38
(8-2) nd2n = 1.52
(8-3) νd2p = 23.80
(8-4) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(8-5) νd1pf = 95.25
(8-6) nd1n = 1.61
(8-7) TL1a / TL1 = 0.47
(8-8) νd1bp = 82.57

2A and 2B are graphs showing various aberrations when the optical system according to the first example of the present application is focused on an object at infinity and focused on a short distance object, respectively.
FIG. 3 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the first example of the present application. The shift amount in the direction orthogonal to the optical axis of the shift lens group in FIG. 3 is 1.40 mm.

In each aberration diagram, FNO represents an F number, and Y represents an image height. d indicates the aberration at the d-line (wavelength 587.6 nm), and g indicates the aberration at the g-line (wavelength 435.8 nm). In the astigmatism diagram, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. The coma aberration diagram shows coma aberration at each image height Y. Note that the same reference numerals as in this embodiment are used in the aberration diagrams of each embodiment described later.
From the respective aberration diagrams, it can be seen that the optical system according to the present embodiment corrects various aberrations well and has excellent imaging performance, and also has excellent imaging performance during lens shift.

Here, the cause of the occurrence of ghost and flare in the optical system according to the present embodiment will be described.
FIG. 30 is a diagram illustrating an example of a state in which light rays incident on the optical system according to the present embodiment are reflected by the first reflecting surface and the second reflecting surface to form ghosts and flares on the image plane I. is there.
In FIG. 30, when a light beam BM from the object side enters the optical system as shown, a part of the light beam BM is an object side lens surface (surface number 27, 27) of the biconvex positive lens L36 in the third lens group G3. It is reflected by the first reflecting surface where the reflected light that becomes ghost or flare is generated, and further the image side lens surface (surface number 24, ghost or flare) of the biconcave negative lens L34 in the third lens group G3. The second reflected surface where the reflected light is generated is reflected again, and finally reaches the image plane I to generate ghost and flare. The first reflecting surface is a concave lens surface when viewed from the image surface side, and the second reflecting surface is a concave lens surface when viewed from the image surface side.
Therefore, the optical system according to the present embodiment suppresses the generation of reflected light by effectively forming ghosts and flares by forming an antireflection film corresponding to light rays having a wide incident angle in a wide wavelength range on the lens surface. Can be reduced.

(Second embodiment)
FIG. 4 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a second example common to the first to eighth embodiments of the present application.
The optical system according to this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. And G3. An aperture stop S is provided between the second lens group G2 and the third lens group G3, and a filter FL is provided between the third lens group G3 and the image plane I.

In the optical system according to the present example, an antireflection film described later is formed on the image surface side lens surface (surface number 24) of the biconcave negative lens L34 of the third lens group G3.

Under the above configuration, in the optical system according to the present embodiment, the second lens group G2 is moved to the image side along the optical axis, thereby focusing from an object at infinity to a near object. Note that the position of the aperture stop S is fixed with respect to the image plane I during focusing. In addition, the shooting distance of the optical system according to the present embodiment when focusing on a short-distance object is 2.6 m.
In the optical system according to the present example, the third lens group G3 in the third lens group G3 is shifted to include a component in a direction orthogonal to the optical axis as a shift lens group, thereby performing image stabilization.
Table 2 below lists values of specifications of the optical system according to the present example.

(Table 2) Second Example
[Surface data]
m r d nd νd
OP ∞ ∞

1 1200.3704 5.00 1.51680 63.88
2 1199.7897 1.00
3 205.7091 17.50 1.43385 95.25
4 -1134.8251 45.00
5 173.6014 18.00 1.43385 95.25
6 -417.4854 3.07
7 -374.6983 6.00 1.61266 44.46
8 347.6771 90.00
9 66.1559 4.00 1.79500 45.31
10 45.7808 15.00 1.49782 82.57
11 874.9561 Variable
12 -2545.8867 2.50 1.77250 49.62
13 114.9779 3.35
14 -271.4306 3.50 1.84666 23.80
15 -87.3926 2.40 1.51823 58.82
16 63.5469 Variable
17 (S) ∞ 2.00

18 87.7161 7.60 1.48749 70.31
19 -64.5076 1.20
20 -66.7841 1.90 1.84666 23.80
21 -116.0392 5.00
22 325.4187 3.50 1.84666 23.80
23 -134.7294 1.90 1.59319 67.90
24 52.9625 3.60
25 -331.8219 1.90 1.75500 52.34
26 98.9972 4.00
27 117.6253 3.50 1.77250 49.62
28 -402.3365 0.10
29 67.6197 4.50 1.64000 60.20
30 -391.1361 1.90 1.84666 23.80
31 264.8450 9.00

32 ∞ 2.00 1.51680 63.88
33 ∞ Bf

I ∞

[Various data]
f 391.99
FNO 2.88
2ω 6.29
Y 21.63
TL 397.00
Bf 71.300

When focusing on an object at infinity When focusing on a near object f or β 391.991 -0.174
d0 ∞ 2203.000
d11 18.344 33.670
d16 37.438 22.112
Bf 71.300 71.300

[Lens group data]
ST f
G1 1 179.8867
G2 12 -67.1696
G3 18 160.1914

[Conditional expression values]
fF = 331.5552
fR = -976.6517
f = 391.9914
f1 = 179.8867
f1a = 354.4332
f1b = 193.1145
f2 = -67.1696
f12 = 1088.5976
f3a = 129.0469
f3bc = -976.6517
νdp = 95.25 (L11), 95.25 (L12)
ndn = 1.51823
νdn = 58.82
βs = -4.6800
βr = −0.2526

(First embodiment)
(1-1) f / f12 = 0.36
(1-2) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(1-3) νd1pf = 95.25
(1-4) nd1n = 1.61
(1-5) TL1a / TL1 = 0.47
(1-6) νd1bp = 82.57
(1-7) νd2p = 23.80

(Second Embodiment)
(2-1) f / f12 = 0.36
(2-2) nd2n = 1.52
(2-3) νd2p = 23.80
(2-4) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(2-5) νd1pf = 95.25
(2-6) nd1n = 1.61
(2-7) TL1a / TL1 = 0.47
(2-8) νd1bp = 82.57

(Third embodiment)
(3-1) βr × (1-βs) = − 1.4349
(3-2) f3a / f3bc = -0.1321
(3-3) f1a / f1b = 1.8354
(3-4) νdp = 95.25 (L11), 95.25 (L12)
(3-5) ndn = 1.51823
(3-6) νdn = 58.82
(3-7) f1 / f2 = -2.6781
(3-8) f / f12 = 0.3601

(Fourth embodiment)
(4-1) | fR / fF | = 2.9457
(4-2) βr × (1-βs) = − 1.4349
(4-3) f3a / f3bc = -0.1321
(4-4) f1a / f1b = 1.8354
(4-5) νdp = 95.25 (L11), 95.25 (L12)
(4-6) ndn = 1.51823
(4-7) νdn = 58.82
(4-8) f1 / f2 = -2.6781
(4-9) f / f12 = 0.3601

(Fifth embodiment)
(5-1) | fR / fF | = 2.9457
(5-2) βr × (1-βs) = − 1.4349
(5-3) f3a / f3bc = -0.1321
(5-4) f1a / f1b = 1.8354
(5-5) νdp = 95.25 (L11), 95.25 (L12)
(5-6) ndn = 1.51823
(5-7) νdn = 58.82
(5-8) f1 / f2 = -2.6781
(5-9) f / f12 = 0.3601

(Sixth embodiment)
(6-1) βr × (1-βs) = − 1.4349
(6-2) f3a / f3bc = -0.1321
(6-3) f1a / f1b = 1.8354
(6-4) νdp = 95.25 (L11), 95.25 (L12)
(6-5) ndn = 1.51823
(6-6) νdn = 58.82
(6-7) f1 / f2 = -2.6781
(6-8) f / f12 = 0.3601

(Seventh embodiment)
(7-1) f / f12 = 0.36
(7-2) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(7-3) νd1pf = 95.25
(7-4) nd1n = 1.61
(7-5) TL1a / TL1 = 0.47
(7-6) νd1bp = 82.57
(7-7) νd2p = 23.80

(Eighth embodiment)
(8-1) f / f12 = 0.36
(8-2) nd2n = 1.52
(8-3) νd2p = 23.80
(8-4) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(8-5) νd1pf = 95.25
(8-6) nd1n = 1.61
(8-7) TL1a / TL1 = 0.47
(8-8) νd1bp = 82.57

FIGS. 5A and 5B are graphs showing various aberrations when the optical system according to Example 2 of the present application is focused on an object at infinity and focused on a short distance object, respectively.
FIG. 6 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the second example of the present application. The shift amount in the direction orthogonal to the optical axis of the shift lens group in FIG. 6 is 1.40 mm.
From the respective aberration diagrams, it can be seen that the optical system according to the present embodiment corrects various aberrations well and has excellent imaging performance, and also has excellent imaging performance during lens shift.

(Third embodiment)
FIG. 7 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a third example common to the first to eighth embodiments of the present application.
The optical system according to this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. And G3. An aperture stop S is provided between the second lens group G2 and the third lens group G3, and a filter FL is provided between the third lens group G3 and the image plane I.

The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface directed toward the object side, and a cemented negative lens composed of a positive meniscus lens L22 having a concave surface directed toward the object side and a biconcave negative lens L23. Consists of.

In the optical system according to the present example, an antireflection film described later is formed on the image surface side lens surface (surface number 11) of the positive meniscus lens L15 of the first lens group G1.

Under the above configuration, in the optical system according to the present embodiment, the second lens group G2 is moved to the image side along the optical axis, thereby focusing from an object at infinity to a near object. Note that the position of the aperture stop S is fixed with respect to the image plane I during focusing. In addition, the shooting distance of the optical system according to the present embodiment when focusing on a short-distance object is 2.6 m.
In the optical system according to the present example, the third lens group G3 in the third lens group G3 is shifted to include a component in a direction orthogonal to the optical axis as a shift lens group, thereby performing image stabilization.
Table 3 below lists values of specifications of the optical system according to the present example.

(Table 3) Third Example
[Surface data]
m r d nd νd
OP ∞ ∞

1 1200.3704 5.00 1.51680 63.88
2 1199.7897 1.00
3 207.0795 17.50 1.43384 95.26
4 -1127.5309 44.90
5 175.9698 18.00 1.43384 95.26
6 -397.2708 3.07
7 -360.2396 6.00 1.61266 44.46
8 353.1837 90.00
9 66.4844 4.00 1.79500 45.32
10 45.9182 15.00 1.49782 82.54
11 1114.1067 Variable
12 2992.5492 2.50 1.75500 52.34
13 118.0399 3.35
14 -241.6942 3.50 1.84668 23.83
15 -86.4136 2.40 1.53996 59.52
16 64.2643 Variable
17 (S) ∞ 1.50

18 90.0336 7.60 1.48749 70.43
19 -63.8039 1.20
20 -65.9768 1.90 1.84668 23.83
21 -114.8763 5.00
22 300.3587 3.50 1.84668 23.83
23 -128.0558 1.90 1.59319 67.94
24 53.9004 3.10
25 -347.5421 1.90 1.75500 52.33
26 94.5337 4.19
27 118.3533 3.50 1.77250 49.68
28 -384.3825 0.10
29 67.4622 4.50 1.64000 60.14
30 -340.4206 1.90 1.84668 23.83
31 246.6417 6.50

32 ∞ 1.50 1.51680 63.88
33 ∞ Bf

I ∞

[Various data]
f 392.00
FNO 2.89
2ω 6.28
Y 21.63
TL 396.91
Bf 74.220

When focusing on an object at infinity When focusing on a near object f or β 392.000 -0.173
d0 ∞ 2203.010
d11 18.503 33.773
d16 38.179 22.909
Bf 74.220 73.906

[Lens group data]
ST f
G1 1 179.1160
G2 12 -67.4099
G3 18 162.8784

[Conditional expression values]
fF = 332.9301
fR = -963.3744
f = 392.0000
f1 = 179.1160
f1a = 358.2095
f1b = 190.5264
f2 = -67.4099
f12 = 1061.9447
f3a = 131.3711
f3bc = -963.3744
νdp = 95.26 (L11), 95.26 (L12)
ndn = 1.53996
νdn = 59.52
βs = -4.9878
βr = −0.2361

(First embodiment)
(1-1) f / f12 = 0.37
(1-2) νd1p = 95.26 (L11), 95.26 (L12), 82.54 (L15)
(1-3) νd1pf = 95.26
(1-4) nd1n = 1.61
(1-5) TL1a / TL1 = 0.47
(1-6) νd1bp = 82.54
(1-7) νd2p = 23.83

(Second Embodiment)
(2-1) f / f12 = 0.37
(2-2) nd2n = 1.54
(2-3) νd2p = 23.83
(2-4) νd1p = 95.26 (L11), 95.26 (L12), 82.54 (L15)
(2-5) νd1pf = 95.26
(2-6) nd1n = 1.61
(2-7) TL1a / TL1 = 0.47
(2-8) νd1bp = 82.54

(Third embodiment)
(3-1) βr × (1-βs) = − 1.4135
(3-2) f3a / f3bc = -0.1364
(3-3) f1a / f1b = 1.8801
(3-4) νdp = 95.26 (L11), 95.26 (L12)
(3-5) ndn = 1.53996
(3-6) νdn = 59.52
(3-7) f1 / f2 = -2.6571
(3-8) f / f12 = 0.3691

(Fourth embodiment)
(4-1) | fR / fF | = 2.8936
(4-2) βr × (1-βs) = − 1.4135
(4-3) f3a / f3bc = -0.1364
(4-4) f1a / f1b = 1.8801
(4-5) νdp = 95.26 (L11), 95.26 (L12)
(4-6) ndn = 1.53996
(4-7) νdn = 59.52
(4-8) f1 / f2 = -2.6571
(4-9) f / f12 = 0.3691

(Fifth embodiment)
(5-1) | fR / fF | = 2.8936
(5-2) βr × (1-βs) = − 1.4135
(5-3) f3a / f3bc = -0.1364
(5-4) f1a / f1b = 1.8801
(5-5) νdp = 95.26 (L11), 95.26 (L12)
(5-6) ndn = 1.53996
(5-7) νdn = 59.52
(5-8) f1 / f2 = -2.6571
(5-9) f / f12 = 0.3691

(Sixth embodiment)
(6-1) βr × (1-βs) = − 1.4135
(6-2) f3a / f3bc = -0.1364
(6-3) f1a / f1b = 1.8801
(6-4) νdp = 95.26 (L11), 95.26 (L12)
(6-5) ndn = 1.53996
(6-6) νdn = 59.52
(6-7) f1 / f2 = -2.6571
(6-8) f / f12 = 0.3691

(Seventh embodiment)
(7-1) f / f12 = 0.37
(7-2) νd1p = 95.26 (L11), 95.26 (L12), 82.54 (L15)
(7-3) νd1pf = 95.26
(7-4) nd1n = 1.61
(7-5) TL1a / TL1 = 0.47
(7-6) νd1bp = 82.54
(7-7) νd2p = 23.83

(Eighth embodiment)
(8-1) f / f12 = 0.37
(8-2) nd2n = 1.54
(8-3) νd2p = 23.83
(8-4) νd1p = 95.26 (L11), 95.26 (L12), 82.54 (L15)
(8-5) νd1pf = 95.26
(8-6) nd1n = 1.61
(8-7) TL1a / TL1 = 0.47
(8-8) νd1bp = 82.54

8A and 8B are graphs showing various aberrations when the optical system according to Example 3 of the present application is focused on an object at infinity and focused on a short distance object, respectively.
FIG. 9 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the third example of the present application. In the figure, the shift amount in the direction orthogonal to the optical axis of the shift lens group is 1.43 mm.
From the respective aberration diagrams, it can be seen that the optical system according to the present embodiment corrects various aberrations well and has excellent imaging performance, and also has excellent imaging performance during lens shift.

(Fourth embodiment)
FIG. 10 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a fourth example common to the first to eighth embodiments of the present application.
The optical system according to this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. And G3. An aperture stop S is provided between the second lens group G2 and the third lens group G3, and a filter FL is provided between the third lens group G3 and the image plane I.

In the optical system according to the present example, an antireflection film described later is formed on the image surface side lens surface (surface number 13) of the negative meniscus lens L21 of the second lens group G2.

Under the above configuration, in the optical system according to the present embodiment, the second lens group G2 is moved to the image side along the optical axis, thereby focusing from an object at infinity to a near object. Note that the position of the aperture stop S is fixed with respect to the image plane I during focusing. In addition, the shooting distance of the optical system according to the present embodiment when focusing on a short-distance object is 2.6 m.
In the optical system according to the present example, the third lens group G3 in the third lens group G3 is shifted to include a component in a direction orthogonal to the optical axis as a shift lens group, thereby performing image stabilization.
Table 4 below lists values of specifications of the optical system according to the present example.

(Table 4) Fourth Example
[Surface data]
m r d nd νd
OP ∞ ∞

1 1200.3704 5.00 1.51680 63.88
2 1199.7897 1.00
3 210.9074 17.50 1.43384 95.26
4 -1135.2477 44.90
5 173.4175 18.00 1.43384 95.26
6 -413.8140 3.07
7 -375.4223 6.00 1.61266 44.46
8 358.4435 90.00
9 66.9574 4.00 1.79500 45.32
10 46.1708 15.00 1.49782 82.54
11 1030.2823 Variable
12 10236.2589 2.50 1.77250 49.68
13 110.7581 3.35
14 -289.4383 3.50 1.84668 23.83
15 -96.1712 2.40 1.51680 63.88
16 65.0724 Variable
17 (S) ∞ 1.50

18 86.8540 7.60 1.48749 70.43
19 -62.9408 1.20
20 -65.5511 1.90 1.84668 23.83
21 -118.4244 5.00
22 300.3217 3.50 1.84668 23.83
23 -128.4546 1.90 1.59319 67.94
24 53.9974 3.10
25 -348.7023 1.90 1.75500 52.33
26 93.3844 4.19
27 119.2828 3.50 1.77250 49.68
28 -375.3153 0.10
29 68.1234 4.50 1.64000 60.14
30 -426.6037 1.90 1.84668 23.83
31 243.3294 6.50

32 ∞ 1.50 1.51680 63.88
33 ∞ Bf

I ∞

[Various data]
f 392.00
FNO 2.89
2ω 6.28
Y 21.63
TL 396.91
Bf 74.220

When focusing on an object at infinity When focusing on a near object f or β 392.000 -0.174
d0 ∞ 2203.010
d11 18.503 33.773
d16 38.179 22.909
Bf 74.220 74.374

[Lens group data]
ST f
G1 1 179.5793
G2 12 -68.1638
G3 18 164.8495

[Conditional expression values]
fF = 330.4625
fR = -882.8393
f = 392.0002
f1 = 179.5793
f1a = 354.4299
f1b = 193.6583
f2 = -68.1638
f12 = 1047.8286
f3a = 131.2421
f3bc = -882.8393
νdp = 95.26 (L11), 95.26 (L12)
ndn = 1.51680
νdn = 63.88
βs = -5.0707
βr = −0.2339

(First embodiment)
(1-1) f / f12 = 0.37
(1-2) νd1p = 95.26 (L11), 95.26 (L12), 82.54 (L15)
(1-3) νd1pf = 95.26
(1-4) nd1n = 1.61
(1-5) TL1a / TL1 = 0.47
(1-6) νd1bp = 82.54
(1-7) νd2p = 23.83

(Second Embodiment)
(2-1) f / f12 = 0.37
(2-2) nd2n = 1.52
(2-3) νd2p = 23.83
(2-4) νd1p = 95.26 (L11), 95.26 (L12), 82.54 (L15)
(2-5) νd1pf = 95.26
(2-6) nd1n = 1.61
(2-7) TL1a / TL1 = 0.47
(2-8) νd1bp = 82.54

(Third embodiment)
(3-1) βr × (1-βs) = − 1.4202
(3-2) f3a / f3bc = -0.1487
(3-3) f1a / f1b = 1.8302
(3-4) νdp = 95.26 (L11), 95.26 (L12)
(3-5) ndn = 1.51680
(3-6) νdn = 63.88
(3-7) f1 / f2 = -2.6345
(3-8) f / f12 = 0.3741

(Fourth embodiment)
(4-1) | fR / fF | = 2.6715
(4-2) βr × (1-βs) = − 1.4202
(4-3) f3a / f3bc = -0.1487
(4-4) f1a / f1b = 1.8302
(4-5) νdp = 95.26 (L11), 95.26 (L12)
(4-6) ndn = 1.51680
(4-7) νdn = 63.88
(4-8) f1 / f2 = -2.6345
(4-9) f / f12 = 0.3741

(Fifth embodiment)
(5-1) | fR / fF | = 2.6715
(5-2) βr × (1-βs) = − 1.4202
(5-3) f3a / f3bc = -0.1487
(5-4) f1a / f1b = 1.8302
(5-5) νdp = 95.26 (L11), 95.26 (L12)
(5-6) ndn = 1.51680
(5-7) νdn = 63.88
(5-8) f1 / f2 = -2.6345
(5-9) f / f12 = 0.3741

(Sixth embodiment)
(6-1) βr × (1-βs) = − 1.4202
(6-2) f3a / f3bc = -0.1487
(6-3) f1a / f1b = 1.8302
(6-4) νdp = 95.26 (L11), 95.26 (L12)
(6-5) ndn = 1.51680
(6-6) νdn = 63.88
(6-7) f1 / f2 = -2.6345
(6-8) f / f12 = 0.3741

(Seventh embodiment)
(7-1) f / f12 = 0.37
(7-2) νd1p = 95.26 (L11), 95.26 (L12), 82.54 (L15)
(7-3) νd1pf = 95.26
(7-4) nd1n = 1.61
(7-5) TL1a / TL1 = 0.47
(7-6) νd1bp = 82.54
(7-7) νd2p = 23.83

(Eighth embodiment)
(8-1) f / f12 = 0.37
(8-2) nd2n = 1.52
(8-3) νd2p = 23.83
(8-4) νd1p = 95.26 (L11), 95.26 (L12), 82.54 (L15)
(8-5) νd1pf = 95.26
(8-6) nd1n = 1.61
(8-7) TL1a / TL1 = 0.47
(8-8) νd1bp = 82.54

11A and 11B are graphs showing various aberrations when the optical system according to Example 4 of the present application is focused on an object at infinity and focused on a short distance object, respectively.
FIG. 12 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the fourth example of the present application. The shift amount in the direction orthogonal to the optical axis of the shift lens group in FIG. 12 is 1.43 mm.
From the respective aberration diagrams, it can be seen that the optical system according to the present embodiment corrects various aberrations well and has excellent imaging performance, and also has excellent imaging performance during lens shift.

(5th Example)
FIG. 13 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a fifth example common to the first to eighth embodiments of the present application.
The optical system according to this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. And G3. An aperture stop S is provided between the second lens group G2 and the third lens group G3, and a filter FL is provided between the third lens group G3 and the image plane I.

The optical system according to this example includes an object of the image side lens surface (surface number 6) of the biconvex positive lens L12 of the first lens group G1 and the biconcave negative lens L13 of the first lens group G1. An antireflection film described later is formed on the side lens surface (surface number 7).

Under the above configuration, in the optical system according to the present embodiment, the second lens group G2 is moved to the image side along the optical axis, thereby focusing from an object at infinity to a near object. Note that the position of the aperture stop S is fixed with respect to the image plane I during focusing. In addition, the shooting distance of the optical system according to the present embodiment when focusing on a short-distance object is 2.6 m.
In the optical system according to the present example, the third lens group G3 in the third lens group G3 is shifted to include a component in a direction orthogonal to the optical axis as a shift lens group, thereby performing image stabilization.
Table 5 below lists values of specifications of the optical system according to the present example.

(Table 5) Fifth Example
[Surface data]
m r d nd νd
OP ∞ ∞

1 1200.3704 5.00 1.51680 63.88
2 1199.7897 1.00
3 237.4785 15.50 1.43385 95.25
4 -1507.8850 45.00
5 198.3323 19.00 1.43385 95.25
6 -342.1796 3.00
7 -327.8324 6.00 1.61266 44.46
8 772.9939 93.00
9 70.7391 5.40 1.79952 42.09
10 47.9832 16.00 1.49782 82.57
11 1681.9346 Variable
12 -2709.1390 3.00 1.77250 49.62
13 136.3998 3.50
14 -487.1729 4.00 1.84666 23.80
15 -108.0510 2.50 1.51742 52.20
16 59.4298 Variable
17 (S) ∞ 2.00

18 228.1074 5.25 1.59319 67.90
19 -85.4981 0.60
20 -124.4314 1.90 2.00069 25.46
21 -295.5719 3.85
22 294.4912 3.30 1.84666 23.80
23 -171.7558 1.90 1.59319 67.90
24 54.4393 4.05
25 -281.8305 1.90 1.69680 55.52
26 152.6451 2.94
27 104.2002 3.00 1.77250 49.62
28 -1538.2155 0.10
29 71.9218 4.80 1.57957 53.74
30 -155.3605 1.90 1.84666 23.80
31 1092.5548 11.00

32 ∞ 2.00 1.51680 63.88
33 ∞ Bf

I ∞

[Various data]
f 391.99
FNO 2.88
2ω 6.27
Y 21.60
TL 399.38
Bf 70.081

When focusing on an object at infinity When focusing on a near object f or β 391.990 -0.172
d0 ∞ 2203.007
d11 16.500 31.900
d16 40.401 25.001
Bf 70.081 70.033

[Lens group data]
ST f
G1 1 177.7760
G2 12 -73.1720
G3 18 187.9179

[Conditional expression values]
fF = 393.5513
fR = 1215.0131
f = 391.9899
f1 = 177.7760
f1a = 340.8186
f1b = 201.6693
f2 = -73.1720
f12 = 774.8291
f3a = 204.7509
f3bc = 1215.0131
νdp = 95.25 (L11), 95.25 (L12)
ndn = 1.51742
νdn = 52.20
βs = -5.2108
βr = −0.1912

(First embodiment)
(1-1) f / f12 = 0.51
(1-2) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(1-3) νd1pf = 95.25
(1-4) nd1n = 1.61
(1-5) TL1a / TL1 = 0.45
(1-6) νd1bp = 82.57
(1-7) νd2p = 23.80

(Second Embodiment)
(2-1) f / f12 = 0.51
(2-2) nd2n = 1.52
(2-3) νd2p = 23.80
(2-4) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(2-5) νd1pf = 95.25
(2-6) nd1n = 1.61
(2-7) TL1a / TL1 = 0.45
(2-8) νd1bp = 82.57

(Third embodiment)
(3-1) βr × (1-βs) =-1.1872
(3-2) f3a / f3bc = 0.1685
(3-3) f1a / f1b = 1.6900
(3-4) νdp = 95.25 (L11), 95.25 (L12)
(3-5) ndn = 1.51742
(3-6) νdn = 52.20
(3-7) f1 / f2 = -2.4296
(3-8) f / f12 = 0.5059

(Fourth embodiment)
(4-1) | fR / fF | = 3.0873
(4-2) βr × (1-βs) = − 1.1872
(4-3) f3a / f3bc = 0.1685
(4-4) f1a / f1b = 1.6900
(4-5) νdp = 95.25 (L11), 95.25 (L12)
(4-6) ndn = 1.51742
(4-7) νdn = 52.20
(4-8) f1 / f2 = -2.4296
(4-9) f / f12 = 0.5059

(Fifth embodiment)
(5-1) | fR / fF | = 3.0873
(5-2) βr × (1-βs) = − 1.1872
(5-3) f3a / f3bc = 0.1685
(5-4) f1a / f1b = 1.6900
(5-5) νdp = 95.25 (L11), 95.25 (L12)
(5-6) ndn = 1.51742
(5-7) νdn = 52.20
(5-8) f1 / f2 = -2.4296
(5-9) f / f12 = 0.5059

(Sixth embodiment)
(6-1) βr × (1-βs) =-1.1872
(6-2) f3a / f3bc = 0.1685
(6-3) f1a / f1b = 1.6900
(6-4) νdp = 95.25 (L11), 95.25 (L12)
(6-5) ndn = 1.51742
(6-6) νdn = 52.20
(6-7) f1 / f2 = -2.4296
(6-8) f / f12 = 0.5059

(Seventh embodiment)
(7-1) f / f12 = 0.51
(7-2) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(7-3) νd1pf = 95.25
(7-4) nd1n = 1.61
(7-5) TL1a / TL1 = 0.45
(7-6) νd1bp = 82.57
(7-7) νd2p = 23.80

(Eighth embodiment)
(8-1) f / f12 = 0.51
(8-2) nd2n = 1.52
(8-3) νd2p = 23.80
(8-4) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(8-5) νd1pf = 95.25
(8-6) nd1n = 1.61
(8-7) TL1a / TL1 = 0.45
(8-8) νd1bp = 82.57

FIGS. 14A and 14B are graphs showing various aberrations when the optical system according to Example 5 of the present application is focused on an object at infinity and focused on a short distance object, respectively.
FIG. 15 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to Example 5 of the present application. The shift amount in the direction orthogonal to the optical axis of the shift lens group in FIG. 15 is 1.68 mm.
From the respective aberration diagrams, it can be seen that the optical system according to the present embodiment corrects various aberrations well and has excellent imaging performance, and also has excellent imaging performance during lens shift.

(Sixth embodiment)
FIG. 16 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a sixth example common to the first to eighth embodiments of the present application.
The optical system according to this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. And G3. An aperture stop S is provided between the second lens group G2 and the third lens group G3, and a filter FL is provided between the third lens group G3 and the image plane I.

The second lens group G2 includes, in order from the object side, a negative meniscus lens L21 having a convex surface facing the object side, a positive meniscus lens L22 having a concave surface facing the object side, and a negative meniscus lens L23 having a concave surface facing the object side. It consists of a cemented negative lens.

The third lens group G3 includes, in order from the object side, a third a lens group G3a having a positive refractive power, a third b lens group G3b having a negative refractive power, and a third c lens group G3c having a positive refractive power. It is composed of
The third-a lens group G3a is composed of, in order from the object side, a biconvex positive lens L31 and a negative meniscus lens L32 having a concave surface facing the object side.
The third lens group G3b includes, in order from the object side, a cemented lens of a positive meniscus lens L33 having a concave surface directed toward the object side and a biconcave negative lens L34, and a negative meniscus lens L35 having a convex surface directed toward the object side. Become.
The third c lens group G3c includes, in order from the object side, a biconvex positive lens L36, and a cemented lens of a biconvex positive lens L37 and a biconcave negative lens L38.

In the optical system according to the present example, an antireflection film described later is formed on the object side lens surface (surface number 14) of the positive meniscus lens L22 of the second lens group G2.

Under the above configuration, in the optical system according to the present embodiment, the second lens group G2 is moved to the image side along the optical axis, thereby focusing from an object at infinity to a near object. Note that the position of the aperture stop S is fixed with respect to the image plane I during focusing. In addition, the shooting distance of the optical system according to the present embodiment when focusing on a short-distance object is 2.6 m.
In the optical system according to the present example, the third lens group G3 in the third lens group G3 is shifted to include a component in a direction orthogonal to the optical axis as a shift lens group, thereby performing image stabilization.
Table 6 below lists values of specifications of the optical system according to the present example.

(Table 6) Sixth Example
[Surface data]
m r d nd νd
OP ∞ ∞

1 1200.3704 5.00 1.51680 63.88
2 1199.7897 1.50
3 217.9147 15.50 1.43385 95.25
4 -2272.2650 45.00
5 191.4672 18.50 1.43385 95.25
6 -388.7337 3.24
7 -366.9736 6.00 1.61266 44.46
8 692.0557 90.02
9 65.4296 5.20 1.80610 40.97
10 45.0727 15.00 1.49782 82.57
11 760.0090 Variable
12 2386.5723 2.50 1.81600 46.59
13 64.7944 6.50
14 -159.3202 4.50 1.80809 22.74
15 -67.3666 2.00 1.61772 49.81
16 -4529.1486 Variable
17 (S) ∞ 2.00

18 128.3829 8.00 1.59319 67.90
19 -58.5025 0.60
20 -58.7397 1.90 1.79504 28.69
21 -122.7539 5.79
22 -216.6393 3.30 1.84666 23.80
23 -61.9303 1.90 1.59319 67.90
24 59.0225 3.00
25 728.9238 1.90 1.81600 46.59
26 93.0674 4.00
27 141.2086 3.00 1.77250 49.62
28 -1505.6719 0.15
29 69.4894 4.80 1.74320 49.26
30 -136.7089 1.90 1.84666 23.80
31 672.4408 9.00

32 ∞ 2.00 1.51680 63.88
33 ∞ Bf

I ∞

[Various data]
f 392.00
FNO 2.88
2ω 6.27
Y 21.60
TL 400.00
Bf 71.300

When focusing on an object at infinity When focusing on a near object f or β 392.000 -0.173
d0 ∞ 2200.000
d11 17.463 31.763
d16 37.536 23.236
Bf 71.300 71.260

[Lens group data]
ST f
G1 1 172.5113
G2 12 -69.4949
G3 18 175.8293

[Conditional expression values]
fF = 315.0175
fR = -754.0300
f = 391.9996
f1 = 172.5113
f1a = 329.5860
f1b = 194.9749
f2 = -69.4949
f12 = 859.4613
f3a = 130.1736
f3bc = -754.0300
νdp = 95.25 (L11), 95.25 (L12)
ndn = 1.61772
νdn = 49.81
βs = -4.6014
βr = −0.2704

(First embodiment)
(1-1) f / f12 = 0.46
(1-2) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(1-3) νd1pf = 95.25
(1-4) nd1n = 1.61
(1-5) TL1a / TL1 = 0.46
(1-6) νd1bp = 82.57
(1-7) νd2p = 22.74

(Second Embodiment)
(2-1) f / f12 = 0.46
(2-2) nd2n = 1.62
(2-3) νd2p = 22.74
(2-4) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(2-5) νd1pf = 95.25
(2-6) nd1n = 1.61
(2-7) TL1a / TL1 = 0.46
(2-8) νd1bp = 82.57

(Third embodiment)
(3-1) βr × (1-βs) = − 1.5148
(3-2) f3a / f3bc = -0.1726
(3-3) f1a / f1b = 1.6904
(3-4) νdp = 95.25 (L11), 95.25 (L12)
(3-5) ndn = 1.61772
(3-6) νdn = 49.81
(3-7) f1 / f2 = -2.4824
(3-8) f / f12 = 0.4561

(Fourth embodiment)
(4-1) | fR / fF | = 2.3936
(4-2) βr × (1-βs) = − 1.5148
(4-3) f3a / f3bc = -0.1726
(4-4) f1a / f1b = 1.6904
(4-5) νdp = 95.25 (L11), 95.25 (L12)
(4-6) ndn = 1.61772
(4-7) νdn = 49.81
(4-8) f1 / f2 = -2.4824
(4-9) f / f12 = 0.4561

(Fifth embodiment)
(5-1) | fR / fF | = 2.3936
(5-2) βr × (1-βs) = − 1.5148
(5-3) f3a / f3bc = -0.1726
(5-4) f1a / f1b = 1.6904
(5-5) νdp = 95.25 (L11), 95.25 (L12)
(5-6) ndn = 1.61772
(5-7) νdn = 49.81
(5-8) f1 / f2 = -2.4824
(5-9) f / f12 = 0.4561

(Sixth embodiment)
(6-1) βr × (1-βs) = − 1.5148
(6-2) f3a / f3bc = -0.1726
(6-3) f1a / f1b = 1.6904
(6-4) νdp = 95.25 (L11), 95.25 (L12)
(6-5) ndn = 1.61772
(6-6) νdn = 49.81
(6-7) f1 / f2 = -2.4824
(6-8) f / f12 = 0.4561

(Seventh embodiment)
(7-1) f / f12 = 0.46
(7-2) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(7-3) νd1pf = 95.25
(7-4) nd1n = 1.61
(7-5) TL1a / TL1 = 0.46
(7-6) νd1bp = 82.57
(7-7) νd2p = 22.74

(Eighth embodiment)
(8-1) f / f12 = 0.46
(8-2) nd2n = 1.62
(8-3) νd2p = 22.74
(8-4) νd1p = 95.25 (L11), 95.25 (L12), 82.57 (L15)
(8-5) νd1pf = 95.25
(8-6) nd1n = 1.61
(8-7) TL1a / TL1 = 0.46
(8-8) νd1bp = 82.57

FIGS. 17A and 17B are graphs showing various aberrations when the optical system according to Example 6 of the present application is focused on an object at infinity and focused on a short distance object, respectively.
FIG. 18 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the sixth example of the present application. The shift amount in the direction orthogonal to the optical axis of the shift lens group in FIG. 18 is 1.35 mm.
From the respective aberration diagrams, it can be seen that the optical system according to the present embodiment corrects various aberrations well and has excellent imaging performance, and also has excellent imaging performance during lens shift.

(Seventh embodiment)
FIG. 19 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to a seventh example common to the third to sixth embodiments of the present application.
The optical system according to this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. And G3. An aperture stop S is provided between the second lens group G2 and the third lens group G3, and a filter FL is provided between the third lens group G3 and the image plane I.

Under the above configuration, in the optical system according to the present embodiment, the second lens group G2 is moved to the image side along the optical axis, thereby focusing from an object at infinity to a near object. Note that the position of the aperture stop S is fixed with respect to the image plane I during focusing. In addition, the shooting distance of the optical system according to the present embodiment when focusing on a short-distance object is 2.6 m.
In the optical system according to the present example, the third lens group G3 in the third lens group G3 is shifted to include a component in a direction orthogonal to the optical axis as a shift lens group, thereby performing image stabilization.
Table 7 below lists values of specifications of the optical system according to the present example.

(Table 7) Seventh Example
[Surface data]
m r d nd νd
OP ∞ ∞

1 1200.3704 5.00 1.51680 63.88
2 1199.7897 1.00
3 205.8380 17.50 1.43385 95.25
4 -3344.1817 45.00
5 195.7037 18.50 1.43385 95.25
6 -339.8777 3.00
7 -326.8303 6.00 1.61266 44.46
8 717.5240 90.00
9 66.8199 5.00 1.79952 42.09
10 45.8756 14.00 1.49782 82.57
11 533.8513 Variable
12 -1418.6433 2.50 1.80100 34.92
13 69.1598 5.00
14 -669.4067 4.50 1.84666 23.80
15 -70.8153 2.00 1.69680 55.52
16 269.4654 Variable
17 (S) ∞ 2.00

18 111.8330 8.00 1.59319 67.90
19 -67.7933 0.60
20 -69.4674 1.90 1.79504 28.69
21 -144.5287 7.60
22 -307.1811 3.30 1.84666 23.80
23 -70.7922 1.90 1.59319 67.90
24 58.1065 3.00
25 2403.0294 1.90 1.75500 52.34
26 93.8065 4.00
27 118.1336 3.00 1.77250 49.62
28 -440.5940 0.10
29 66.8592 4.80 1.77250 49.62
30 -269.8337 1.90 1.84666 23.80
31 146.9087 9.00

32 ∞ 2.00 1.51680 63.88
33 ∞ Bf

I ∞

[Various data]
f 392.00
FNO 2.93
2ω 6.27
Y 21.60
TL 400.89
Bf 71.811

When focusing on an object at infinity When focusing on a near object f or β 391.998 -0.174
d0 ∞ 2203.000
d11 17.408 32.808
d16 37.666 22.266
Bf 71.811 71.696

[Lens group data]
ST f
G1 1 179.2995
G2 12 -71.1930
G3 18 172.8661

[Conditional expression values]
fF = 309.4988
fR = -531.9883
f = 391.9977
f1 = 179.2995
f1a = 329.8985
f1b = 210.3126
f2 = -71.1930
f12 = 993.1645
f3a = 123.9352
f3bc = -531.9883
νdp = 95.25 (L11), 95.25 (L12)
ndn = 1.69680
νdn = 55.52
βs = -5.1022
βr = −0.2482

(Third embodiment)
(3-1) βr × (1-βs) = − 1.5148
(3-2) f3a / f3bc = -0.2330
(3-3) f1a / f1b = 1.5686
(3-4) νdp = 95.25 (L11), 95.25 (L12)
(3-5) ndn = 1.69680
(3-6) νdn = 55.52
(3-7) f1 / f2 = -2.5185
(3-8) f / f12 = 0.3947

(Fourth embodiment)
(4-1) | fR / fF | = 1.7189
(4-2) βr × (1-βs) = − 1.5148
(4-3) f3a / f3bc = -0.2330
(4-4) f1a / f1b = 1.5686
(4-5) νdp = 95.25 (L11), 95.25 (L12)
(4-6) ndn = 1.69680
(4-7) νdn = 55.52
(4-8) f1 / f2 = -2.5185
(4-9) f / f12 = 0.3947

(Fifth embodiment)
(5-1) | fR / fF | = 1.7189
(5-2) βr × (1-βs) = − 1.5148
(5-3) f3a / f3bc = -0.2330
(5-4) f1a / f1b = 1.5686
(5-5) νdp = 95.25 (L11), 95.25 (L12)
(5-6) ndn = 1.69680
(5-7) νdn = 55.52
(5-8) f1 / f2 = -2.5185
(5-9) f / f12 = 0.3947

(Sixth embodiment)
(6-1) βr × (1-βs) = − 1.5148
(6-2) f3a / f3bc = -0.2330
(6-3) f1a / f1b = 1.5686
(6-4) νdp = 95.25 (L11), 95.25 (L12)
(6-5) ndn = 1.69680
(6-6) νdn = 55.52
(6-7) f1 / f2 = -2.5185
(6-8) f / f12 = 0.3947

20A and 20B are graphs showing various aberrations when the optical system according to Example 7 of the present application is focused on an object at infinity and focused on a short distance object, respectively.
FIG. 21 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the seventh example of the present application. Note that the shift amount in the direction orthogonal to the optical axis of the shift lens group in FIG. 21 is 1.35 mm.
From the respective aberration diagrams, it can be seen that the optical system according to the present embodiment corrects various aberrations well and has excellent imaging performance, and also has excellent imaging performance during lens shift.

(Eighth embodiment)
FIG. 22 is a cross-sectional view showing a lens arrangement at the time of focusing on an object at infinity of an optical system according to an eighth example common to the third to sixth embodiments of the present application.
The optical system according to this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. And G3. An aperture stop S is provided between the second lens group G2 and the third lens group G3, and a filter FL is provided between the third lens group G3 and the image plane I.

The third lens group G3 includes, in order from the object side, a third a lens group G3a having a positive refractive power, a third b lens group G3b having a negative refractive power, and a third c lens group G3c having a positive refractive power. It is composed of
The third-a lens group G3a is composed of, in order from the object side, a biconvex positive lens L31 and a negative meniscus lens L32 having a concave surface facing the object side.
The third lens group G3b is composed of, in order from the object side, a cemented lens of a positive meniscus lens L33 having a concave surface directed toward the object side and a biconcave negative lens L34, and a biconcave negative lens L35.
The third c lens group G3c includes, in order from the object side, a biconvex positive lens L36, and a cemented lens of a biconvex positive lens L37 and a biconcave negative lens L38.

Under the above configuration, in the optical system according to the present embodiment, the second lens group G2 is moved to the image side along the optical axis, thereby focusing from an object at infinity to a near object. Note that the position of the aperture stop S is fixed with respect to the image plane I during focusing. In addition, the shooting distance of the optical system according to the present embodiment when focusing on a short-distance object is 2.6 m.
In the optical system according to the present example, the third lens group G3 in the third lens group G3 is shifted to include a component in a direction orthogonal to the optical axis as a shift lens group, thereby performing image stabilization.
Table 8 below provides values of specifications of the optical system according to the present example.

(Table 8) Eighth Example
[Surface data]
m r d nd νd
OP ∞ ∞

1 1200.3704 5.00 1.51680 63.88
2 1199.7897 1.50
3 232.9803 15.50 1.43385 95.25
4 -1439.6122 45.00
5 181.4353 18.50 1.43385 95.25
6 -403.8411 3.27
7 -381.3927 6.00 1.61266 44.46
8 616.0014 91.44
9 68.9182 5.40 1.80610 40.97
10 47.0662 15.50 1.49782 82.57
11 783.4341 Variable
12 -1054.8550 2.50 1.80100 34.92
13 73.2883 5.00
14 -1414.1001 4.50 1.84666 23.80
15 -76.6008 2.00 1.69100 54.93
16 209.5153 Variable
17 (S) ∞ 2.00

18 158.0460 8.00 1.59319 67.90
19 -62.8829 0.60
20 -64.4824 1.90 1.79504 28.69
21 -131.7441 7.60
22 -544.1422 3.30 1.84666 23.80
23 -78.4731 1.90 1.59319 67.90
24 60.2986 4.15
25 -1406.4760 1.90 1.75500 52.34
26 91.4315 4.00
27 97.5172 3.00 1.77250 49.62
28 -457.9700 0.50
29 73.3485 4.80 1.74400 44.81
30 -160.3113 1.90 1.84666 23.80
31 190.4630 9.00

32 ∞ 2.00 1.51680 63.88
33 ∞ Bf

I ∞

[Various data]
f 392.00
FNO 2.88
2ω 6.28
Y 21.63
TL 400.00
Bf 71.30

When focusing on an object at infinity When focusing on a near object f or β 392.000 -0.173
d0 ∞ 2200.000
d11 15.740 31.040
d16 35.300 20.000
Bf 71.300 71.300

[Lens group data]
ST f
G1 1 177.9658
G2 12 -72.7082
G3 18 181.1444

[Conditional expression values]
fF = 332.3433
fR = -1237.2508
f = 392.0000
f1 = 177.9658
f1a = 326.9111
f1b = 208.4317
f2 = -72.7082
f12 = 870.7966
f3a = 145.4495
f3bc = -1237.2508
νdp = 95.25 (L11), 95.25 (L12)
ndn = 1.69100
νdn = 54.93
βs = -3.8225
βr = -0.3086

(Third embodiment)
(3-1) βr × (1-βs) =-1.4881
(3-2) f3a / f3bc = -0.1176
(3-3) f1a / f1b = 1.5684
(3-4) νdp = 95.25 (L11), 95.25 (L12)
(3-5) ndn = 1.69100
(3-6) νdn = 54.93
(3-7) f1 / f2 = -2.4477
(3-8) f / f12 = 0.4502

(Fourth embodiment)
(4-1) | fR / fF | = 3.7228
(4-2) βr × (1-βs) =-1.4881
(4-3) f3a / f3bc = -0.1176
(4-4) f1a / f1b = 1.5684
(4-5) νdp = 95.25 (L11), 95.25 (L12)
(4-6) ndn = 1.69100
(4-7) νdn = 54.93
(4-8) f1 / f2 = -2.4477
(4-9) f / f12 = 0.4502

(Fifth embodiment)
(5-1) | fR / fF | = 3.7228
(5-2) βr × (1-βs) =-1.4881
(5-3) f3a / f3bc = -0.1176
(5-4) f1a / f1b = 1.5684
(5-5) νdp = 95.25 (L11), 95.25 (L12)
(5-6) ndn = 1.69100
(5-7) νdn = 54.93
(5-8) f1 / f2 = -2.4477
(5-9) f / f12 = 0.4502

(Sixth embodiment)
(6-1) βr × (1-βs) =-1.4881
(6-2) f3a / f3bc = -0.1176
(6-3) f1a / f1b = 1.5684
(6-4) νdp = 95.25 (L11), 95.25 (L12)
(6-5) ndn = 1.69100
(6-6) νdn = 54.93
(6-7) f1 / f2 = -2.4477
(6-8) f / f12 = 0.4502

FIGS. 23A and 23B are graphs showing various aberrations when the optical system according to Example 8 of the present application is focused on an object at infinity and focused on a short distance object, respectively.
FIG. 24 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to the eighth example of the present application. Note that the shift amount in the direction perpendicular to the optical axis of the shift lens group in FIG. 24 is 1.35 mm.
From the respective aberration diagrams, it can be seen that the optical system according to the present embodiment corrects various aberrations well and has excellent imaging performance, and also has excellent imaging performance during lens shift.

(Ninth embodiment)
FIG. 25 is a cross-sectional view showing the lens arrangement at the time of focusing on an object at infinity in the optical system according to Example 9 common to Embodiments 3 to 6 of the present application.
The optical system according to this example includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group having a positive refractive power. And G3. An aperture stop S is provided between the second lens group G2 and the third lens group G3, and a filter FL is provided between the third lens group G3 and the image plane I.

The third lens group G3 includes, in order from the object side, a third a lens group G3a having a positive refractive power, a third b lens group G3b having a negative refractive power, and a third c lens group G3c having a positive refractive power. It is composed of
The third-a lens group G3a is composed of, in order from the object side, a biconvex positive lens L31 and a negative meniscus lens L32 having a concave surface facing the object side.
The third lens group G3b includes, in order from the object side, a cemented lens of a positive meniscus lens L33 having a concave surface directed toward the object side and a biconcave negative lens L34, and a negative meniscus lens L35 having a convex surface directed toward the object side. Become.
The third c lens group G3c includes, in order from the object side, a biconvex positive lens L36, a cemented lens of a biconvex positive lens L37, and a negative meniscus lens L38 having a concave surface facing the object side.

Under the above configuration, in the optical system according to the present embodiment, the second lens group G2 is moved to the image side along the optical axis, thereby focusing from an object at infinity to a near object. Note that the position of the aperture stop S is fixed with respect to the image plane I during focusing. In addition, the shooting distance of the optical system according to the present embodiment when focusing on a short-distance object is 2.6 m.
In the optical system according to the present example, the third lens group G3 in the third lens group G3 is shifted to include a component in a direction orthogonal to the optical axis as a shift lens group, thereby performing image stabilization.
Table 9 below provides values of specifications of the optical system according to the present example.

(Table 9) Ninth Example
[Surface data]
m r d nd νd
OP ∞ ∞

1 1200.3704 5.00 1.51680 63.88
2 1199.7897 1.50
3 223.9540 15.50 1.43385 95.25
4 -5879.6456 45.00
5 188.6739 18.50 1.43385 95.25
6 -344.9762 3.24
7 -334.2849 6.00 1.61266 44.46
8 1087.7540 90.02
9 66.7379 5.20 1.80610 40.97
10 45.7359 15.00 1.49782 82.57
11 678.5295 Variable
12 -1447.2643 2.50 1.80100 34.92
13 63.6827 5.00
14 -302.0700 4.50 1.84666 23.80
15 -62.4763 2.00 1.69100 54.93
16 764.0825 Variable
17 (S) ∞ 2.00

18 125.7848 8.00 1.59319 67.90
19 -59.6174 0.60
20 -60.3570 1.90 1.79504 28.69
21 -122.9210 5.79
22 -208.0839 3.30 1.84666 23.80
23 -61.6159 1.90 1.59319 67.90
24 57.2685 3.00
25 880.2836 1.90 1.81600 46.59
26 100.1330 4.00
27 123.7087 3.00 1.77250 49.62
28 1021.0401 0.15
29 75.9029 4.80 1.74320 49.26
30 -107.4055 1.90 1.84666 23.80
31 -5070.3090 9.00

32 ∞ 2.00 1.51680 63.88
33 ∞ Bf

I ∞

[Various data]
f 392.00
FNO 2.88
2ω 6.27
Y 21.60
TL 400.00
Bf 71.300

When focusing on an object at infinity When focusing on a near object f or β 392.000 -0.173
d0 ∞ 2200.000
d11 17.726 32.026
d16 38.772 24.472
Bf 71.300 71.381

[Lens group data]
ST f
G1 1 172.5113
G2 12 -69.4949
G3 18 175.8293

[Conditional expression values]
fF = 308.6113
fR = -645.0699
f = 391.9996
f1 = 172.5113
f1a = 318.0791
f1b = 203.8595
f2 = -69.4949
f12 = 859.4613
f3a = 126.0854
f3bc = -645.0699
νdp = 95.25 (L11), 95.25 (L12)
ndn = 1.69100
νdn = 54.93
βs = -5.1901
βr = −0.2447

(Third embodiment)
(3-1) βr × (1-βs) = − 1.5150
(3-2) f3a / f3bc = -0.1955
(3-3) f1a / f1b = 1.5603
(3-4) νdp = 95.25 (L11), 95.25 (L12)
(3-5) ndn = 1.69100
(3-6) νdn = 54.93
(3-7) f1 / f2 = -2.4824
(3-8) f / f12 = 0.4561

(Fourth embodiment)
(4-1) | fR / fF | = 2.0902
(4-2) βr × (1-βs) = − 1.5150
(4-3) f3a / f3bc = -0.1955
(4-4) f1a / f1b = 1.5603
(4-5) νdp = 95.25 (L11), 95.25 (L12)
(4-6) ndn = 1.69100
(4-7) νdn = 54.93
(4-8) f1 / f2 = -2.4824
(4-9) f / f12 = 0.4561

(Fifth embodiment)
(5-1) | fR / fF | = 2.0902
(5-2) βr × (1-βs) = − 1.5150
(5-3) f3a / f3bc = -0.1955
(5-4) f1a / f1b = 1.5603
(5-5) νdp = 95.25 (L11), 95.25 (L12)
(5-6) ndn = 1.69100
(5-7) νdn = 54.93
(5-8) f1 / f2 = -2.4824
(5-9) f / f12 = 0.4561

(Sixth embodiment)
(6-1) βr × (1-βs) = − 1.5150
(6-2) f3a / f3bc = -0.1955
(6-3) f1a / f1b = 1.5603
(6-4) νdp = 95.25 (L11), 95.25 (L12)
(6-5) ndn = 1.69100
(6-6) νdn = 54.93
(6-7) f1 / f2 = -2.4824
(6-8) f / f12 = 0.4561

FIGS. 26A and 26B are graphs showing various aberrations when the optical system according to Example 9 of the present application is focused on an object at infinity and focused on a short distance object, respectively.
FIG. 27 is a coma aberration diagram when the lens is shifted at the time of focusing on an object at infinity of the optical system according to Example 9 of the present application. The shift amount in the direction orthogonal to the optical axis of the shift lens group in FIG. 27 is 1.35 mm.
From the respective aberration diagrams, it can be seen that the optical system according to the present embodiment corrects various aberrations well and has excellent imaging performance, and also has excellent imaging performance during lens shift.

Here, an antireflection film (also referred to as a multilayer broadband antireflection film) used in the optical system according to the fifth to eighth embodiments of the present application will be described. FIG. 31 is a diagram illustrating an example of a film configuration of an antireflection film. The antireflection film 101 is composed of seven layers and is formed on the optical surface of the optical member 102 such as a lens. The first layer 101a is formed of aluminum oxide deposited by a vacuum deposition method. Further, a second layer 101b made of a mixture of titanium oxide and zirconium oxide deposited by a vacuum deposition method is further formed on the first layer 101a. Further, a third layer 101c made of aluminum oxide deposited by a vacuum deposition method is formed on the second layer 101b, and titanium oxide and zirconium oxide deposited by a vacuum deposition method are formed on the third layer 101c. A fourth layer 101d made of the mixture is formed. Furthermore, a fifth layer 101e made of aluminum oxide deposited by vacuum deposition is formed on the fourth layer 101d, and titanium oxide and zirconium oxide deposited by vacuum deposition on the fifth layer 101e. A sixth layer 101f made of the mixture is formed.

Then, on the sixth layer 101f thus formed, a seventh layer 101g made of a mixture of magnesium fluoride and silica is formed by a wet process to form the antireflection film 101 of this embodiment. For the formation of the seventh layer 101g, a sol-gel method which is a kind of wet process is used. The sol-gel method is a method in which a sol obtained by mixing raw materials is made into a non-flowable gel by hydrolysis / polycondensation reaction, etc., and the gel is heated and decomposed to obtain a product. In the production of an optical thin film, a film can be formed by applying an optical thin film material sol on the optical surface of an optical member and forming a gel film by drying and solidifying. The wet process is not limited to the sol-gel method, and a method of obtaining a solid film without going through a gel state may be used.

As described above, the first layer 101a to the sixth layer 101f of the antireflection film 101 are formed by electron beam evaporation which is a dry process, and the seventh layer 101g which is the uppermost layer is prepared by a hydrofluoric acid / magnesium acetate method. It is formed by the following procedure by a wet process using the prepared sol solution. First, an aluminum oxide layer that becomes the first layer 101a, a titanium oxide-zirconium oxide mixed layer that becomes the second layer 101b, a third layer on the optical surface of the optical member 102 that is a lens film formation surface in advance by using a vacuum evaporation apparatus, An aluminum oxide layer to be the layer 101c, a titanium oxide-zirconium oxide mixed layer to be the fourth layer 101d, an aluminum oxide layer to be the fifth layer 101e, and a titanium oxide-zirconium oxide mixed layer to be the sixth layer 101f are formed in this order. And after taking out the optical member 102 from a vapor deposition apparatus, the thing which added the silicon alkoxide to the sol liquid prepared by the hydrofluoric acid / magnesium acetate method is apply | coated by the spin coat method, The magnesium fluoride used as the 7th layer 101g A layer made of a mixture of silica and silica is formed. The reaction formula when prepared by the hydrofluoric acid / magnesium acetate method is shown in the following formula (a).

(A) 2HF + Mg (CH3COO) 2 → MgF2 + 2CH3COOH

The sol solution used for this film formation is used for film formation after mixing raw materials and subjecting it to high temperature and pressure aging treatment at 140 ° C. for 24 hours in an autoclave. The optical member 102 is completed by heat treatment at 160 ° C. for 1 hour in the air after the seventh layer 101g is formed. By using such a sol-gel method, the seventh layer 101g is formed by depositing particles having a size of several nm to several tens of nm leaving a void.

The optical performance of the optical member having the antireflection film 101 formed in this way will be described using the spectral characteristics shown in FIG.

The lens which is an optical member having the antireflection film according to the fifth to eighth embodiments of the present application is formed under the conditions shown in Table 10 below. Here, Table 10 shows that the reference wavelength is λ and the refractive index of the optical member as the substrate is 1.62, 1.74, and 1.85, the layers 101a (first layer) to 101g (seventh layer) of the antireflection film 101. The optical film thickness of each layer is determined. In Table 10, aluminum oxide is represented by Al2O3, a mixture of titanium oxide and zirconium oxide is represented by ZrO2 + TiO2, and a mixture of magnesium fluoride and silica is represented by MgF2 + SiO2. In Tables 10 to 12, N represents the refractive index and D represents the optical film thickness.

(Table 10)
Substance N D D D
Medium air 1
7th layer MgF2 + SiO2 1.26 0.268λ 0.271λ 0.269λ
6th layer ZrO2 + TiO2 2.12 0.057λ 0.054λ 0.059λ
5th layer Al2O3 1.65 0.171λ 0.178λ 0.162λ
4th layer ZrO2 + TiO2 2.12 0.127λ 0.13λ 0.158λ
3rd layer Al2O3 1.65 0.122λ 0.107λ 0.08λ
Second layer ZrO2 + TiO2 2.12 0.059λ 0.075λ 0.105λ
1st layer Al2O3 1.65 0.257λ 0.03λ 0.03λ
Refractive index of substrate 1.62 1.74 1.85

FIG. 32 shows spectral characteristics when a light beam is vertically incident on an optical member in which the reference wavelength λ is 550 nm in Table 10 and the optical film thickness of each layer of the antireflection film 101 is designed.

32, it can be seen that the optical member having the antireflection film 101 designed with the reference wavelength λ of 550 nm can suppress the reflectance to 0.2% or less over the entire wavelength range of 420 nm to 720 nm. Further, even in the optical member having the antireflection film 101 in which each optical film thickness is designed with the reference wavelength λ as d line (wavelength 587.6 nm) in Table 10, the spectral characteristics are hardly affected, and the reference shown in FIG. Spectral characteristics substantially equivalent to those when the wavelength λ is 550 nm.

Next, a modified example of the antireflection film will be described. This antireflection film consists of five layers, and similarly to Table 10, the optical film thickness of each layer with respect to the reference wavelength λ is designed under the conditions shown in Table 11 below. In this modification, the above-described sol-gel method is used for forming the fifth layer.

(Table 11)
Substance N D D
Medium air 1
5th layer MgF2 + SiO2 1.26 0.275λ 0.269λ
4th layer ZrO2 + TiO2 2.12 0.045λ 0.043λ
3rd layer Al2O3 1.65 0.212λ 0.217λ
Second layer ZrO2 + TiO2 2.12 0.077λ 0.066λ
1st layer Al2O3 1.65 0.288λ 0.290λ
Refractive index of substrate 1.46 1.52

FIG. 33 shows the spectral characteristics when light rays are perpendicularly incident on an optical member having an antireflection film in which the optical film thickness is designed with the refractive index of the substrate being 1.52 and the reference wavelength λ being 550 nm in Table 11. Yes. From FIG. 33, it can be seen that the antireflection film of this modification has a reflectance of 0.2% or less over the entire wavelength range of 420 nm to 720 nm. In Table 11, even an optical member having an antireflection film whose optical film thickness is designed with the reference wavelength λ as the d-line (wavelength 587.6 nm) hardly affects the spectral characteristics, and the spectral characteristics shown in FIG. Has almost the same characteristics.

FIG. 34 shows the spectral characteristics when the incident angle of the light beam to the optical member having the spectral characteristics shown in FIG. 33 is 30, 45, and 60 degrees, respectively. 33 and 34 do not show the spectral characteristics of the optical member having the antireflection film whose refractive index of the substrate shown in Table 11 is 1.46, but the refractive index of the substrate is almost equal to 1.52. Needless to say, it has the following spectral characteristics.

For comparison, FIG. 35 shows an example of an antireflection film formed only by a dry process such as a conventional vacuum deposition method. FIG. 36 shows spectral characteristics when a light beam is perpendicularly incident on an optical member designed with an antireflection film configured under the conditions shown in Table 12 below with a refractive index of 1.52 of the same substrate as in Table 11. FIG. 36 shows the spectral characteristics when the incident angles of the light rays to the optical member having the spectral characteristics shown in FIG. 35 are 30, 45, and 60 degrees, respectively.

(Table 12)
Substance N D
Medium air 1
7th layer MgF2 1.39 0.243λ
6th layer ZrO2 + TiO2 2.12 0.119λ
5th layer Al2O3 1.65 0.057λ
4th layer ZrO2 + TiO2 2.12 0.220λ
3rd layer Al2O3 1.65 0.064λ
Second layer ZrO2 + TiO2 2.12 0.057λ
1st layer Al2O3 1.65 0.193λ
Refractive index of substrate 1.52

When the spectral characteristics of the optical member having the antireflection film according to the fifth to eighth embodiments of the present application shown in FIGS. 32 to 34 are compared with the spectral characteristics of the conventional example shown in FIGS. It can be clearly seen that the antireflection films according to the fifth to eighth embodiments have a lower reflectance at any incident angle and a lower reflectance in a wider band.

Next, an example in which the antireflection film shown in Table 10 and Table 11 is applied to the first to ninth embodiments of the present application will be described.

In the optical system of Example 1 of the present application, the refractive index of the biconcave negative lens L34 of the third lens group G3 is nd = 1.59319, as shown in Table 1, and the third lens group G3 has the refractive index. Since the refractive index of the biconvex positive lens L36 is nd = 1.77250, the antireflection film corresponding to the refractive index of the substrate of 1.62 on the image surface side lens surface of the biconcave negative lens L34. 101 (see Table 11), and an antireflection film (see Table 11) corresponding to a refractive index of the substrate of 1.74 is used on the object-side lens surface of the biconvex positive lens L36. The amount of reflected light can be reduced, and ghost and flare can be reduced.

In the optical system of the second example of the present application, the refractive index of the biconcave negative lens L34 of the third lens group G3 is nd = 1.59319 as shown in Table 2, so By using an antireflection film 101 (see Table 11) having a substrate refractive index of 1.62 on the lens surface on the image plane side of the lens L34, reflected light from each lens surface can be reduced, and ghost and flare can be reduced. can do.

In the optical system of the third example of the present application, the refractive index of the positive meniscus lens L15 of the first lens group G1 is nd = 1.49782 as shown in Table 3, so that the image plane side of the positive meniscus lens L15 is By using the antireflection film 101 (see Table 10) corresponding to the refractive index of the substrate of 1.52 on the lens surface, the reflected light from each lens surface can be reduced, and ghost and flare can be reduced.

In the optical system of the fourth example of the present application, the refractive index of the negative meniscus lens L21 of the second lens group G2 is nd = 1.77250 as shown in Table 4, so that the image plane side of the negative meniscus lens L21 is By using the antireflection film 101 (see Table 11) corresponding to the refractive index of the substrate of 1.74 on the lens surface, the reflected light from each lens surface can be reduced, and ghost and flare can be reduced.

In the optical system of Example 5 of the present application, the refractive index of the biconvex positive lens L12 of the first lens group G1 is nd = 1.43385, as shown in Table 5, and the refractive index of the first lens group G1 Since the refractive index of the biconcave negative lens L13 is nd = 1.66266, the antireflective film corresponding to the refractive index of the substrate corresponding to the refractive index of 1.46 on the image surface side lens surface of the biconvex positive lens L12. 101 (see Table 10), and an antireflection film (see Table 11) corresponding to a refractive index of the substrate of 1.62 is used on the object-side lens surface of the biconcave negative lens L13. The amount of reflected light can be reduced, and ghost and flare can be reduced.

In the optical system of the sixth example of the present application, the refractive index of the positive meniscus lens L22 of the second lens group G2 is nd = 1.80809 as shown in Table 6, so that the object side of the positive meniscus lens L22 has an object side. By using an antireflection film 101 (see Table 11) corresponding to a refractive index of the substrate of 1.85 on the lens surface, reflected light from each lens surface can be reduced, and ghost and flare can be reduced.

In the optical system of the seventh example of the present application, the refractive index of the biconcave negative lens L34 of the third lens group G3 is nd = 1.59319 as shown in Table 7, and the refractive index of the third lens group G3 Since the refractive index of the biconvex positive lens L36 is nd = 1.77250, the antireflection film corresponding to the refractive index of the substrate of 1.62 on the image surface side lens surface of the biconcave negative lens L34. 101 (see Table 11), and an antireflection film (see Table 11) corresponding to a refractive index of the substrate of 1.74 is used on the object-side lens surface of the biconvex positive lens L36. The amount of reflected light can be reduced, and ghost and flare can be reduced.

In the optical system of the eighth example of the present application, the refractive index of the biconvex positive lens L12 of the first lens group G1 is nd = 1.43385, as shown in Table 8, and the refractive index of the first lens group G1 Since the refractive index of the biconcave negative lens L13 is nd = 1.66266, the antireflective film corresponding to the refractive index of the substrate corresponding to the refractive index of 1.46 on the image surface side lens surface of the biconvex positive lens L12. 101 (see Table 10), and an antireflection film (see Table 11) corresponding to a refractive index of the substrate of 1.62 is used on the object-side lens surface of the biconcave negative lens L13. The amount of reflected light can be reduced, and ghost and flare can be reduced.

In the optical system of the ninth example of the present application, the refractive index of the positive meniscus lens L22 of the second lens group G2 is nd = 1.84666 as shown in Table 9, so that the object side of the positive meniscus lens L22 has an object side. By using an antireflection film 101 (see Table 11) corresponding to a refractive index of the substrate of 1.85 on the lens surface, reflected light from each lens surface can be reduced, and ghost and flare can be reduced.

According to the examples of the fourth and fifth embodiments, it is possible to realize an optical system that is small and light, corrects various aberrations favorably, and has excellent optical performance. In particular, the optical systems according to the examples of the fourth and fifth embodiments have an angle of view of 4 to 9 degrees, and can suppress deterioration of optical performance during lens shift.
Further, according to each of the first to third and sixth to eighth embodiments, it has a field angle of 4 to 9 degrees, is small and light, corrects various aberrations satisfactorily, and optically shifts the lens. It is possible to realize an optical system that suppresses deterioration in performance.
In addition, each said Example has shown one specific example of this invention, and this invention is not limited to these. The following contents can be appropriately adopted as long as the optical performance of the optical system according to the first to eighth embodiments of the present application is not impaired.

Although a three-group configuration is shown as a numerical example of the optical system according to the first to eighth embodiments of the present application, the present application is not limited to this, and optical elements of other group configurations (for example, the fourth group and the fifth group) A system can also be constructed. Specifically, a configuration in which a lens or a lens group is added to the most object side or the most image side of the optical system according to the first to eighth embodiments of the present application may be used. In addition, although the optical system according to each of the above embodiments includes the protective filter glass on the most object side in the first lens group, the optical system may be configured without this.

The optical systems according to the first to eighth embodiments of the present application include a part of a lens group, an entire lens group, or a plurality of lens groups in order to perform focusing from an object at infinity to a near object. The focusing lens group may be moved in the optical axis direction. In particular, it is preferable that at least a part of the second lens group is a focusing lens group. Such a focusing lens group can be applied to autofocus, and is also suitable for driving by an autofocus motor such as an ultrasonic motor.

Further, in the optical systems according to the first to eighth embodiments of the present application, either the entire lens group or a part thereof is moved as a vibration-proof lens group so as to include a component in a direction perpendicular to the optical axis, Or it can also be set as the structure which shake-proofs by carrying out rotational movement (oscillation) to the in-plane direction containing an optical axis. In particular, in the optical systems according to the first to eighth embodiments of the present application, it is preferable that at least a part of the third lens group is an anti-vibration lens group.

Further, the lens surface of the lens constituting the optical system according to the first to eighth embodiments of the present application may be a spherical surface, a flat surface, or an aspheric surface. When the lens surface is a spherical surface or a flat surface, it is preferable because lens processing and assembly adjustment are easy, and deterioration of optical performance due to errors in lens processing and assembly adjustment can be prevented. Further, even when the image plane is deviated, it is preferable because there is little deterioration in drawing performance. When the lens surface is aspherical, any of aspherical surface by grinding, glass mold aspherical surface in which glass is molded into an aspherical shape, or composite aspherical surface in which resin provided on the glass surface is formed in an aspherical shape Good. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

In the optical systems according to the first to eighth embodiments of the present application, it is preferable that the aperture stop is disposed in the vicinity of the object side of the third lens group, and the role of the aperture stop is replaced by a lens frame without providing a member. It is good also as composition to do.

Further, an antireflection film having a high transmittance in a wide wavelength region may be applied to the lens surface of the lens constituting the optical system according to the first to eighth embodiments of the present application. Thereby, flare and ghost can be reduced, and high optical performance with high contrast can be achieved.

Next, a camera including an optical system according to the first to eighth embodiments of the present application will be described with reference to FIG.
FIG. 28 is a diagram showing a configuration of a camera including an optical system according to the first to eighth embodiments of the present application.
The camera 1 is a lens-interchangeable digital single-lens reflex camera provided with the optical system according to the first embodiment as the photographing lens 2.
In the present camera 1, light from an object (not shown) that is a subject is collected by the photographing lens 2 and imaged on the focusing screen 4 via the quick return mirror 3. The light imaged on the focusing screen 4 is reflected in the pentaprism 5 a plurality of times and guided to the eyepiece lens 6. Thus, the photographer can observe the subject image as an erect image through the eyepiece 6.

Further, when a release button (not shown) is pressed by the photographer, the quick return mirror 3 is retracted out of the optical path, and light from the subject (not shown) reaches the image sensor 7. Thereby, the light from the subject is picked up by the image pickup device 7 and recorded as a subject image in a memory (not shown). In this way, the photographer can shoot the subject with the camera 1.

Here, the optical system according to the first example mounted on the camera 1 as the photographing lens 2 is small as described above, and has excellent optical performance by satisfactorily correcting various aberrations. That is, the camera 1 can achieve downsizing and high performance. Even if a camera having the optical system according to the second to ninth embodiments mounted as the taking lens 2 is configured, the same effect as the camera 1 can be obtained. Further, even when the optical system according to each of the above embodiments is mounted on a camera having a configuration that does not include the quick return mirror 3, the same effect as the camera 1 can be obtained.

Finally, an outline of the optical system manufacturing method according to the first to eighth embodiments of the present application will be described with reference to FIGS.
FIG. 38 is a diagram showing an outline of the method of manufacturing the optical system according to the first embodiment of the present application.
The optical system manufacturing method according to the first embodiment of the present application shown in FIG. 38 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive A method of manufacturing an optical system having a third lens group having refractive power, which includes the following steps S11 and S12.

Step S11: First to third lens groups are prepared so that the optical system satisfies the following conditional expression (1-1), and each lens group is sequentially arranged in the lens barrel from the object side.
(1-1) 0.10 <f / f12 <0.55
However,
f: Focal length of optical system f12: Composite focal length of first lens group and second lens group at the time of focusing on an object at infinity

Step S12: By providing a known moving mechanism, the second lens group is moved along the optical axis, thereby focusing from an object at infinity to an object at a short distance.

According to the method of manufacturing an optical system according to the first embodiment of the present application, it is possible to manufacture an optical system that is small and has good optical performance.

FIG. 39 is a diagram showing an outline of a method for manufacturing an optical system according to the second embodiment of the present application.
The optical system manufacturing method according to the second embodiment of the present application shown in FIG. 39 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive A method of manufacturing an optical system having a third lens group having refractive power, which includes the following steps S21 to S23.

Step S21: The second lens group has at least three lenses.
Step S22: First to third lens groups are prepared so that the optical system satisfies the following conditional expression (2-1), and each lens group is sequentially arranged in the barrel from the object side.
(2-1) 0.10 <f / f12 <0.85
However,
f: Focal length of optical system f12: Composite focal length of first lens group and second lens group at the time of focusing on an object at infinity

Step S23: By providing a known moving mechanism, the second lens group is moved along the optical axis so as to focus from an object at infinity to a near object.

According to the method for manufacturing an optical system according to the second embodiment of the present application, it is possible to manufacture an optical system having a small size and good optical performance.

FIG. 40 is a diagram showing an outline of the manufacturing method of the optical system according to the third embodiment of the present application.
The optical system manufacturing method according to the third embodiment of the present application shown in FIG. 40 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive A method of manufacturing an optical system having a third lens group having refractive power, which includes the following steps S31 to S33.

Step S31: First to third lens groups are prepared, and each lens group is sequentially arranged in the lens barrel from the object side. Then, by providing a known moving mechanism, the second lens group moves along the optical axis when focusing from an object at infinity to an object at a short distance.

Step S32: By providing a known moving mechanism, a part of the third lens group moves as a shift lens group so as to include a component in a direction orthogonal to the optical axis.

Step S33: The optical system is made to satisfy the following conditional expression (3-1).
(3-1) -1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

According to the optical system manufacturing method according to the third embodiment of the present application, it is possible to manufacture an optical system that corrects various aberrations satisfactorily and suppresses deterioration in optical performance during lens shift.

FIG. 41 is a diagram showing an outline of a method of manufacturing an optical system according to the fourth embodiment of the present application.
The manufacturing method of the optical system according to the fourth embodiment of the present application shown in FIG. 41 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive A method of manufacturing an optical system having a third lens group having refractive power, which includes the following steps S41 to S44.

Step S41: First to third lens groups are prepared, and the third lens group has a 3a lens group and a 3b lens group in order from the object side. Then, each lens group is arranged in the lens barrel in order from the object side.

Step S42: By providing a known moving mechanism, the second lens group is moved along the optical axis when focusing from an object at infinity to an object at a short distance.

Step S43: By providing a known moving mechanism, the 3b lens group is moved as a shift lens group so as to include a component in a direction orthogonal to the optical axis.

Step S44: The optical system is made to satisfy the following conditional expression (4-1).
(4-1) 1.70 <| fR / fF | <5.00
However,
fF: Combined focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: All the positions located on the image side from the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Synthetic focal length of the lens

According to the method of manufacturing an optical system according to the fourth embodiment of the present application, it is possible to manufacture a small optical system having excellent optical performance by satisfactorily correcting various aberrations.

FIG. 29 is a diagram showing an outline of a method of manufacturing an optical system according to the fifth embodiment of the present application.
The optical system manufacturing method according to the fifth embodiment shown in FIG. 29 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive A method for manufacturing an optical system having a third lens group having refractive power, which includes the following steps S51 to S55.

Step S51: First to third lens groups are prepared, and an antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is wet. At least one layer formed using the process is included, and each lens group is arranged in the lens barrel in order from the object side.

Step S52: The third lens group has a 3a lens group and a 3b lens group in order from the object side.

Step S53: By providing a known moving mechanism, the second lens group is moved along the optical axis when focusing from an object at infinity to an object at a short distance.

Step S54: By providing a known moving mechanism, the 3b lens group is moved as a shift lens group so as to include a component in a direction orthogonal to the optical axis.

Step S55: The optical system is made to satisfy the following conditional expression (5-1).
(5-1) 1.70 <| fR / fF | <5.00
However,
fF: Combined focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: All the positions located on the image side from the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Synthetic focal length of the lens

According to the method of manufacturing an optical system according to the fifth embodiment of the present application, it is possible to manufacture a small optical system having excellent optical performance by satisfactorily correcting various aberrations.

FIG. 37 is a diagram showing an outline of a method of manufacturing an optical system according to the sixth embodiment of the present application.
The optical system manufacturing method according to the sixth embodiment of the present application shown in FIG. 37 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive A method of manufacturing an optical system having a third lens group having refractive power, which includes the following steps S61 to S64.

Step S61: First to third lens groups are prepared, and an antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is wet. At least one layer formed using the process is included, and each lens group is arranged in the lens barrel in order from the object side.

Step S62: By providing a known moving mechanism, the second lens group is moved along the optical axis when focusing from an object at infinity to an object at a short distance.

Step S63: By providing a known moving mechanism, a part of the third lens group moves as a shift lens group so as to include a component in a direction orthogonal to the optical axis.

Step S64: The optical system is made to satisfy the following conditional expression (6-1).
(6-1) −1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group

According to the method of manufacturing an optical system according to the sixth embodiment of the present application, it is possible to manufacture an optical system that corrects various aberrations satisfactorily and suppresses deterioration of optical performance during lens shift.

FIG. 42 is a diagram showing an outline of the method of manufacturing the optical system according to the seventh embodiment of the present application.
The optical system manufacturing method according to the seventh embodiment of the present application shown in FIG. 42 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive A method of manufacturing an optical system having a third lens group having refractive power, which includes the following steps S71 to S73.

Step S71: An antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film has at least one layer formed using a wet process. Each lens group is arranged in the lens barrel in order from the object side.

Step S72: First to third lens groups are prepared so that the optical system satisfies the following conditional expression (7-1).
(7-1) 0.10 <f / f12 <0.55
However,
f: Focal length of optical system f12: Composite focal length of first lens group and second lens group at the time of focusing on an object at infinity

Step S73: By providing a known moving mechanism, the second lens group is moved along the optical axis, thereby focusing from an object at infinity to an object at a short distance.

According to the optical system manufacturing method according to the seventh embodiment of the present application, it is possible to manufacture an optical system that is small and has good optical performance.

FIG. 43 is a diagram showing an outline of the manufacturing method of the optical system according to the eighth embodiment of the present application.
The optical system manufacturing method according to the eighth embodiment of the present application shown in FIG. 43 includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive A method of manufacturing an optical system having a third lens group having refractive power, which includes the following steps S81 to S84.

Step S81: An antireflection film is provided on at least one of the optical surfaces in the first lens group, the second lens group, and the third lens group, and the antireflection film has at least one layer formed by using a wet process. Each lens group is arranged in the lens barrel in order from the object side.

Step S82: The second lens group has at least three lenses.
Step S83: First to third lens groups are prepared so that the optical system satisfies the following conditional expression (8-1):
(8-1) 0.10 <f / f12 <0.85
However,
f: Focal length of optical system f12: Composite focal length of first lens group and second lens group at the time of focusing on an object at infinity

Step S84: By providing a known moving mechanism, the second lens group is moved along the optical axis so as to focus from an object at infinity to an object at short distance.

According to the method of manufacturing an optical system according to the eighth embodiment of the present application, it is possible to manufacture an optical system having a small size and good optical performance.

Claims

In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
By moving the second lens group along the optical axis, focusing from an object at infinity to an object at a short distance,
An optical system satisfying the following conditional expression:
0.10 <f / f12 <0.55
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity
The optical system according to claim 1, wherein the first lens group includes at least one positive lens that satisfies the following conditional expression.
80 <νd1p <110
However,
νd1p: Abbe number with respect to d-line of the glass material of the positive lens in the first lens group
The first lens group includes a plurality of positive lenses;
The optical system according to claim 1, wherein a positive lens disposed closest to the object among the plurality of positive lenses satisfies the following conditional expression.
80 <νd1pf <110
However,
νd1pf: Abbe number with respect to d-line of the glass material of the positive lens arranged closest to the object side among the plurality of positive lenses in the first lens group
The optical system according to claim 1, wherein the first lens group includes at least one negative lens that satisfies the following conditional expression.
1.50 <nd1n <1.75
However,
nd1n: Refractive index with respect to d-line of the glass material of the negative lens in the first lens group
The optical system according to claim 1, wherein at least a part of the third lens group moves so as to include a component in a direction orthogonal to the optical axis.
The third lens group includes, in order from the object side, a 3a lens group having a positive refractive power, a 3b lens group having a negative refractive power, and a third c lens group having a positive refractive power. ,
2. The optical system according to claim 1, wherein the third lens group moves so as to include a component in a direction orthogonal to the optical axis.
The optical system according to claim 1, wherein the first lens group includes a cemented lens of a negative lens and a positive lens in order from the object side.
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 1, wherein the following conditional expression is satisfied.
0.30 <TL1a / TL1 <0.70
However,
TL1a: length along the optical axis of the first lens group TL1: length along the optical axis of the first lens group
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 1, wherein the first b lens group includes a positive lens that satisfies the following conditional expression.
70 <νd1bp <110
However,
νd1bp: Abbe number with respect to d-line of the glass material of the positive lens in the 1b lens group
The optical system according to claim 1, wherein the second lens group has two negative lens components.
The optical system according to claim 1, wherein the second lens group includes a positive lens that satisfies the following conditional expression.
15 <νd2p <30
However,
νd2p: Abbe number with respect to d-line of the glass material of the positive lens in the second lens group
An antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is a layer formed using a wet process. The optical system according to claim 1, wherein at least one layer is included.
An optical apparatus comprising the optical system according to claim 1.
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
By moving the second lens group along the optical axis, focusing from an object at infinity to an object at a short distance,
The second lens group has at least three lenses;
An optical system satisfying the following conditional expression:
0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity
The optical system according to claim 14, wherein at least two of the at least three lenses in the second lens group are negative lenses.
The optical system according to claim 14, wherein the second lens group includes at least one negative lens that satisfies the following conditional expression.
1.45 <nd2n <1.65
However,
nd2n: refractive index with respect to d-line of the glass material of the negative lens in the second lens group
The optical system according to claim 14, wherein the second lens group includes a positive lens that satisfies the following conditional expression.
15 <νd2p <30
However,
νd2p: Abbe number with respect to d-line of the glass material of the positive lens in the second lens group
The optical system according to claim 14, wherein the first lens group includes at least one positive lens that satisfies the following conditional expression.
80 <νd1p <110
However,
νd1p: Abbe number with respect to d-line of the glass material of the positive lens in the first lens group
The first lens group includes a plurality of positive lenses;
The optical system according to claim 14, wherein a positive lens disposed closest to the object among the plurality of positive lenses satisfies the following conditional expression.
80 <νd1pf <110
However,
νd1pf: Abbe number with respect to d-line of the glass material of the positive lens arranged closest to the object side among the plurality of positive lenses in the first lens group
The optical system according to claim 14, wherein the first lens group includes at least one negative lens that satisfies the following conditional expression.
1.50 <nd1n <1.75
However,
nd1n: Refractive index with respect to d-line of the glass material of the negative lens in the first lens group
15. The optical system according to claim 14, wherein at least a part of the third lens group moves so as to include a component in a direction orthogonal to the optical axis.
The third lens group includes, in order from the object side, a 3a lens group having a positive refractive power, a 3b lens group having a negative refractive power, and a third c lens group having a positive refractive power. ,
The optical system according to claim 14, wherein the third lens group group moves so as to include a component in a direction orthogonal to the optical axis.
The optical system according to claim 14, wherein the first lens group includes a cemented lens of a negative lens and a positive lens in order from the object side.
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 14, wherein the following conditional expression is satisfied.
0.30 <TL1a / TL1 <0.70
However,
TL1a: length along the optical axis of the first lens group TL1: length along the optical axis of the first lens group
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 14, wherein the first-b lens group includes a positive lens that satisfies the following conditional expression.
70 <νd1bp <110
However,
νd1bp: Abbe number with respect to d-line of the glass material of the positive lens in the 1b lens group
An antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is a layer formed using a wet process. The optical system according to claim 14, comprising at least one layer.
An optical apparatus comprising the optical system according to claim 14.
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
When focusing from an object at infinity to a near object, the second lens group moves along the optical axis;
A part of the third lens group moves as a shift lens group so as to include a component in a direction orthogonal to the optical axis;
An optical system satisfying the following conditional expression:
−1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group
The third lens group includes, in order from the object side, a 3a lens group, a 3b lens group, and a 3c lens group,
29. The optical system according to claim 28, wherein the third lens group is moved so as to include a component in a direction orthogonal to the optical axis as the shift lens group.
The third lens group includes, in order from the object side, a 3a lens group, a 3b lens group, and a 3c lens group,
The optical system according to claim 28, wherein the 3a lens group includes a positive lens and a negative lens.
The optical system according to claim 28, wherein the shift lens group includes a cemented lens of a positive lens and a negative lens and a negative lens in order from the object side.
The third lens group includes, in order from the object side, a 3a lens group, a 3b lens group, and a 3c lens group,
The optical system according to claim 28, further comprising an aperture stop on the object side or the image side of the third-a lens group.
The third lens group includes, in order from the object side, a 3a lens group, a 3b lens group, and a 3c lens group,
The third lens group moves as the shift lens group so as to include a component in a direction orthogonal to the optical axis,
The optical system according to claim 28, wherein the following conditional expression is satisfied:
−0.45 <f3a / f3bc <0.40
However,
f3a: focal length of the 3a lens group f3bc: combined focal length of the 3b lens group and the 3c lens group at the time of focusing on an object at infinity
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 28, wherein the first-a lens group has a negative lens closest to the image side.
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 28, wherein the following conditional expression is satisfied:
1.40 <f1a / f1b <2.05
However,
f1a: focal length of the 1a lens group f1b: focal length of the 1b lens group
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 28, wherein the first-a lens group includes a protective glass, a positive lens, a positive lens, and a negative lens in order from the object side.
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 28, wherein the first-b lens group includes a cemented lens of a negative meniscus lens having a convex surface directed toward the object side and a positive lens in order from the object side.
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 28, wherein the first-a lens group has at least one positive lens that satisfies the following conditional expression.
90 <νdp
However,
νdp: Abbe number with respect to d-line of the glass material of the positive lens in the 1a lens group
The second lens group includes a plurality of negative lenses;
29. The optical system according to claim 28, wherein a negative lens arranged closest to the image side among the plurality of negative lenses satisfies the following conditional expression.
ndn <1.65
However,
ndn: Refractive index with respect to d-line of the glass material of the negative lens arranged closest to the image among the plurality of negative lenses in the second lens group
The second lens group includes a plurality of negative lenses;
29. The optical system according to claim 28, wherein a negative lens arranged closest to the object among the plurality of negative lenses satisfies the following conditional expression.
49.7 <νdn
However,
νdn: Abbe number with respect to d-line of the glass material of the negative lens arranged closest to the object among the plurality of negative lenses in the second lens group
The optical system according to claim 28, wherein the following conditional expression is satisfied:
-3.00 <f1 / f2 <-2.00
However,
f1: Focal length of the first lens group f2: Focal length of the second lens group
The optical system according to claim 28, wherein the second lens group includes, in order from the object side, a negative lens having a concave surface facing the image side, and a cemented lens of a positive lens and a negative lens. system.
The optical system according to claim 28, wherein the following conditional expression is satisfied:
0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity
An antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is a layer formed using a wet process. The optical system according to claim 28, comprising at least one layer.
An optical apparatus comprising the optical system according to claim 28.
In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
The third lens group includes, in order from the object side, a 3a lens group and a 3b lens group,
When focusing from an object at infinity to a near object, the second lens group moves along the optical axis;
The third lens group moves as a shift lens group so as to include a component in a direction perpendicular to the optical axis,
An optical system satisfying the following conditional expression:
1.70 <| fR / fF | <5.00
However,
fF: Composite focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: Nearer to the image side than the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Combined focal length of all lenses located
47. The optical system according to claim 46, wherein the following conditional expression is satisfied.
−1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group
The optical system according to claim 46, wherein the third-a lens group includes a positive lens and a negative lens.
The optical system according to claim 46, wherein the 3b lens group includes a cemented lens of a positive lens and a negative lens and a negative lens in order from the object side.
The optical system according to claim 46, further comprising an aperture stop on the object side or the image side of the third-a lens group.
The third lens group includes, in order from the object side, the third a lens group, the third b lens group, and a third c lens group.
47. The optical system according to claim 46, wherein the following conditional expression is satisfied.
−0.45 <f3a / f3bc <0.40
However,
f3a: focal length of the 3a lens group f3bc: combined focal length of the 3b lens group and the 3c lens group at the time of focusing on an object at infinity
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
47. The optical system according to claim 46, wherein the first lens group has a negative lens closest to the image side.
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
47. The optical system according to claim 46, wherein the following conditional expression is satisfied.
1.40 <f1a / f1b <2.05
However,
f1a: focal length of the 1a lens group f1b: focal length of the 1b lens group
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
47. The optical system according to claim 46, wherein the first-a lens group includes a protective glass, a positive lens, a positive lens, and a negative lens in order from the object side.
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 46, wherein the first-b lens group includes a cemented lens of a negative meniscus lens having a convex surface facing the object side and a positive lens in order from the object side.
The first lens group is composed of a 1a lens group and a 1b lens group in order from the object side,
An air space between the first lens group and the first lens group is the largest of the air spaces in the first lens group;
The optical system according to claim 46, wherein the first-a lens group includes at least one positive lens that satisfies the following conditional expression.
90 <νdp
However,
νdp: Abbe number with respect to d-line of the glass material of the positive lens in the 1a lens group
The second lens group includes a plurality of negative lenses;
47. The optical system according to claim 46, wherein a negative lens arranged closest to the image side among the plurality of negative lenses satisfies the following conditional expression.
ndn <1.65
However,
ndn: Refractive index with respect to d-line of the glass material of the negative lens arranged closest to the image among the plurality of negative lenses in the second lens group
The second lens group includes a plurality of negative lenses;
47. The optical system according to claim 46, wherein a negative lens arranged closest to the object among the plurality of negative lenses satisfies the following conditional expression.
49.7 <νdn
However,
νdn: Abbe number with respect to d-line of the glass material of the negative lens arranged closest to the object among the plurality of negative lenses in the second lens group
47. The optical system according to claim 46, wherein the following conditional expression is satisfied.
-3.00 <f1 / f2 <-2.00
However,
f1: Focal length of the first lens group f2: Focal length of the second lens group
The optical system according to claim 46, wherein the second lens group includes, in order from the object side, a negative lens having a concave surface directed toward the image side, and a cemented lens of a positive lens and a negative lens. system.
47. The optical system according to claim 46, wherein the following conditional expression is satisfied.
0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity
The optical system according to claim 46, wherein the third lens group includes the third a lens group, the third b lens group, and a third c lens group in order from the object side.
An antireflection film is provided on at least one of the optical surfaces of the first lens group, the second lens group, and the third lens group, and the antireflection film is a layer formed using a wet process. The optical system according to claim 46, comprising at least one layer.
An optical device comprising the optical system according to claim 46.
A method of manufacturing an optical system having, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. ,
The optical system satisfies the following conditional expression,
A method of manufacturing an optical system, wherein focusing is performed from an object at infinity to a near object by moving the second lens group along an optical axis.
0.10 <f / f12 <0.55
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity
A method of manufacturing an optical system having, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. ,
The second lens group includes at least three lenses;
The optical system satisfies the following conditional expression,
A method of manufacturing an optical system, wherein focusing is performed from an object at infinity to a near object by moving the second lens group along an optical axis.
0.10 <f / f12 <0.85
However,
f: Focal length of the optical system f12: Composite focal length of the first lens group and the second lens group at the time of focusing on an object at infinity
A method of manufacturing an optical system having, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. ,
The second lens group moves along the optical axis when focusing from an object at infinity to an object at a short distance;
A part of the third lens group moves as a shift lens group so as to include a component in a direction orthogonal to the optical axis;
A method for manufacturing an optical system, characterized in that the optical system satisfies the following conditional expression.
−1.60 <βr × (1-βs) <− 0.85
However,
βs: lateral magnification of the shift lens group βr: lateral magnification of all lenses located on the image side of the shift lens group
A method of manufacturing an optical system having, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. ,
The third lens group has a 3a lens group and a 3b lens group in order from the object side,
The second lens group moves along the optical axis when focusing from an object at infinity to an object at a short distance;
The third lens group is moved so as to include a component in a direction orthogonal to the optical axis as a shift lens group,
A method for manufacturing an optical system, characterized in that the optical system satisfies the following conditional expression.
1.70 <| fR / fF | <5.00
However,
fF: Composite focal length from the first lens group to the 3a lens group at the time of focusing on an object at infinity fR: Nearer to the image side than the 3b lens group and the 3b lens group at the time of focusing on an object at infinity Combined focal length of all lenses located