JP2012042663A - Photographic lens, optical device, and method for adjusting photographic lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost photographic lens capable of achieving excellent optical performance, an optical device having the photographic lens, and a method for adjusting the photographic lens.SOLUTION: The photographic lens includes a first lens group G1 for positive refractive power and a second lens group G2 for positive refractive power in order from an object side. The first lens group G1 comprises a front group for negative refractive power GF and a rear group for refractive power GR in order from the object side. The photographic lens also includes an adjustment mechanism for adjusting the position, by which the front group GF is eccentrically shifted and at least one of the first lens group G1 and the second lens group G2 is eccentrically tilted after assembling the first lens group G1 and the second lens group G2.

Description

  The present invention relates to a photographing lens, an optical device having the same, and a method for adjusting the photographing lens.

  Conventionally, various photographing lenses suitable for a photographic camera, an electronic still camera, a video camera, and the like have been proposed (see, for example, Patent Document 1).

JP 2009-237542 A

  Conventional photographic lenses have a problem that imaging performance deteriorates when an eccentric error occurs during manufacture. In addition, in order to prevent deterioration in imaging performance, it was necessary to increase the shape accuracy of each lens, lens chamber, and mechanism parts to reduce the eccentric error. However, it is difficult to reduce the cost because the processing accuracy must be increased. It was.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a low-cost photographic lens that can achieve good optical performance, an optical device having the photographic lens, and a method for adjusting the photographic lens.

  In order to solve the above-described problems, the present invention includes, in order from the object side, a first lens group having a positive refractive power and a second lens group having a positive refractive power, and the first lens group is arranged from the object side. In order, the front lens group includes a front group having negative refractive power and a rear group having positive refractive power. After assembling the first lens group and the second lens group, the front group is shifted and decentered, and the first lens group and There is provided a photographing lens having an adjustment mechanism for adjusting a position of tilt decentering at least one of the second lens groups.

  In addition, the present invention provides an optical device having the photographing lens.

  Further, the present invention includes a first lens group having a positive refractive power and a second lens group having a positive refractive power in order from the object side, and the first lens group has a negative refractive power in order from the object side. A method for adjusting a photographic lens comprising a front group and a rear group having a positive refractive power, wherein the first lens group and the second lens group are assembled, and then the front group is shifted and decentered, and the first lens There is provided a method for adjusting a photographic lens, characterized in that position adjustment is performed to tilt and decenter at least one of the lens group and the second lens group.

  According to the present invention, it is possible to provide a low-cost photographic lens that can achieve good optical performance, an optical device having the photographic lens, and a method for adjusting the photographic lens.

It is sectional drawing which shows the lens structure of the photographic lens which concerns on 1st Example and 2nd Example. The coma aberration figure with respect to d line | wire (wavelength (lambda) = 587.6nm) in the infinite point focusing state of the imaging lens which concerns on 1st Example and 2nd Example when decentration error does not generate | occur | produce at the time of manufacture is shown. The coma aberration figure with respect to d line | wire (wavelength (lambda) = 587.6nm) in the infinite point focusing state of the imaging lens which concerns on 1st Example when a decentration error generate | occur | produces at the time of manufacture is shown. It is sectional drawing which shows the mechanism of the imaging lens which concerns on 1st Example. FIG. 5 is a diagram showing a mechanism for performing position adjustment for shifting and decentering the front group of the first lens group of the photographing lens shown in FIG. 4, and a mechanism for performing position adjustment for decentering the first lens group and It is the figure seen from the side. In the first embodiment, when there is a decentration error at the time of manufacturing, the image forming performance is corrected by performing position adjustment for shifting and decentering the front group of the first lens group and position adjustment for decentering the first lens group. The coma aberration diagram with respect to the d-line (wavelength λ = 587.6 nm) in the infinite focus state of the photographing lens is shown. It is sectional drawing which shows the mechanism of the imaging lens which concerns on 2nd Example. Example 2 in the case where imaging performance is corrected by performing position adjustment for shifting and decentering the front group of the first lens group and position adjustment for tilting and decentering the second lens group when there is a decentration error during manufacturing. The coma aberration diagram with respect to the d-line (wavelength λ = 587.6 nm) in the infinite focus state of the photographing lens is shown. It is a figure which shows the structure of the camera provided with the imaging lens which concerns on 1st Example.

  Hereinafter, a photographing lens and an adjustment method of the photographing lens according to an embodiment of the present application will be described.

  The photographic lens according to the present embodiment includes a first lens group having a positive refractive power and a second lens group having a positive refractive power in order from the object side. The first lens group is negatively refracted in order from the object side. A front group of force and a rear group of positive refractive power, and after assembling the first lens group and the second lens group, the front group is shifted decentered, and at least one of the first lens group and the second lens group is moved This is a configuration having an adjustment mechanism for adjusting the position for tilt eccentricity.

  With this configuration, it is possible to satisfactorily correct the deterioration of the imaging performance due to the decentration aberration caused by the decentration error during manufacturing. Note that even if an attempt is made to correct only one of the shift decentration of the front group or the tilt decentering of at least one of the first lens group and the second lens group, the decentration aberration of the entire screen cannot be corrected well, and the imaging performance is deteriorated. May not be sufficiently corrected.

  In the photographic lens according to the present embodiment, it is desirable that the adjustment mechanism performs position adjustment that tilts and decenters the first lens group.

  By performing both the position adjustment for shifting and decentering the front group and the position adjustment for tilting and decentering the first lens group, a good correction of the decentration aberration of the entire screen can be realized.

In addition, it is desirable that the photographic lens according to the present embodiment satisfies the following conditional expression (1).
(1) 2.00 <f1 / f <8.00
Here, f1 is the focal length of the first lens group, and f is the focal length of the photographing lens.

  Conditional expression (1) indicates that the focal length of the first lens unit suitable for correcting the deterioration of the imaging performance due to the decentration aberration of the photographic lens by adjusting the position of tilting the first lens unit of the photographic lens. Define the range.

  If the lower limit value of conditional expression (1) is not reached, the refractive power of the first lens group becomes large. Therefore, the amount of decentering aberration generated with respect to the tilt amount of the first lens group becomes excessive, and the tilt amount of the first lens group is reduced. It becomes necessary to make precise adjustments, and it is difficult to achieve cost reduction.

  If the upper limit of conditional expression (1) is exceeded, the refractive power of the first lens group becomes small, so the amount of decentering aberration generated with respect to the tilt amount of the first lens group becomes too small, and is necessary for correcting decentration aberrations. The tilt amount of the first lens group becomes excessive, and the configuration of the photographing lens becomes difficult.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (1) to 3.00.

  In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (1) to 7.00.

  In the photographic lens according to the present embodiment, it is desirable that the adjustment mechanism perform position adjustment that tilts and decenters the second lens group.

  By performing both the position adjustment for shifting and decentering the front group and the position adjustment for tilting and decentering the second lens group, a good correction of the decentration aberration of the entire screen can be realized.

In addition, it is desirable that the photographing lens according to the present embodiment satisfies the following conditional expression (2).
(2) 0.70 <f2 / f <1.40
Here, f2 is the focal length of the second lens group, and f is the focal length of the taking lens.

  Conditional expression (2) indicates that the focal length of the second lens group suitable for correcting the deterioration of the imaging performance due to the decentration aberration of the photographing lens by adjusting the position of tilting the second lens group of the photographing lens. Define the range.

  If the lower limit value of conditional expression (2) is not reached, the refractive power of the second lens group becomes large. Therefore, the amount of decentering aberration with respect to the tilt amount of the second lens group becomes excessive, and the tilt amount of the second lens group is reduced. It becomes necessary to make precise adjustments, and it is difficult to achieve cost reduction.

  If the upper limit value of conditional expression (2) is exceeded, the refractive power of the second lens group becomes small, and therefore the amount of decentration aberration generated with respect to the tilt amount of the second lens group becomes too small, which is necessary for correcting decentration aberrations. The tilt amount of the second lens group becomes excessive, and the configuration of the taking lens becomes difficult.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (2) to 0.85.

  In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (2) to 1.20.

In addition, it is desirable that the photographing lens according to the present embodiment satisfies the following conditional expression (3).
(3) 1.00 <(− fF) / f <2.00
Here, fF is the focal length of the front group, and f is the focal length of the taking lens.

  Conditional expression (3) is a first lens group suitable for correcting deterioration in imaging performance due to decentration aberration of the photographing lens by performing position adjustment for shifting and decentering the front group of the first lens group of the photographing lens. Define the focal length range of the front group.

  If the lower limit value of conditional expression (3) is not reached, the refractive power of the first lens group front group becomes large, so that the amount of decentering aberration with respect to the shift amount of the first lens group front group becomes excessive, and the first lens group. It becomes necessary to precisely adjust the shift amount of the front group, and it is difficult to achieve cost reduction.

  If the upper limit value of conditional expression (3) is exceeded, the refractive power of the front group of the first lens group becomes small, so the amount of decentration aberration generated with respect to the shift amount of the front group of the first lens group becomes too small. The shift amount of the first lens unit front group necessary for correction becomes excessive, and the configuration of the photographing lens becomes difficult.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (3) to 1.20.

  In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (3) to 1.80.

  In the photographic lens according to the present embodiment, it is desirable that the front group is a negative meniscus lens having a convex surface facing the object side.

  With this configuration, the decentration aberration that occurs when the first lens unit front group is shifted and decentered can have characteristics suitable for canceling the decentration aberration that occurs due to manufacturing errors.

In addition, it is desirable that the photographing lens according to the present embodiment satisfies the following conditional expression (4).
(4) -1.90 <(R2 + R1) / (R2-R1) <− 1.02
Where R1 is the radius of curvature of the object side surface of the negative meniscus lens, and R2 is the radius of curvature of the image side surface of the negative meniscus lens.

  Conditional expression (4) indicates that the decentration aberration generated when the first lens group front group is shifted decentered has characteristics suitable for canceling the decentration aberration caused by the manufacturing error. This is a condition that defines the shape of the negative meniscus lens in the group.

  When either the lower limit value or the upper limit value of conditional expression (4) is exceeded, it is difficult to cancel the decentration aberration caused by the manufacturing error due to the decentration aberration generated when the first lens group front group is shifted decentered. It becomes.

  In order to secure the effect of the embodiment, it is preferable to set the lower limit of conditional expression (4) to −1.80.

  In order to secure the effect of the embodiment, it is preferable to set the upper limit of conditional expression (4) to −1.08.

  In addition, the method for adjusting a photographic lens according to the present embodiment includes, in order from the object side, a first lens group having a positive refractive power and a second lens group having a positive refractive power, and the first lens group is located on the object side. In order from the first lens group and the second lens group after assembling the first lens group and the second lens group, the front group is shifted and decentered. Position adjustment for tilt decentering at least one of the first lens group and the second lens group is performed.

  By this adjustment method, it is possible to satisfactorily correct deterioration in imaging performance due to decentration aberration caused by decentration error during manufacturing. Note that even if an attempt is made to correct only one of the shift decentration of the front group or the tilt decentering of at least one of the first lens group and the second lens group, the decentration aberration of the entire screen cannot be corrected well, and the imaging performance is deteriorated. May not be sufficiently corrected.

(Example)
Hereinafter, each example according to the present embodiment will be described with reference to the drawings.

  The photographic lenses according to the first and second examples have the same lens configuration, and are different from each other in adjustment points described later for satisfactorily correcting deterioration in imaging performance due to an eccentric error during manufacture. Therefore, overlapping portions will be described together here.

  FIG. 1 is a cross-sectional view showing the lens configuration of the taking lens according to the first and second examples.

  As shown in FIG. 1, the lens system of the photographing lenses according to the first and second examples includes, in order from the object side along the optical axis, a first lens group G1 having positive refractive power, an aperture S, and the like. And a second lens group G2 having positive refractive power.

  The first lens group G1 includes, in order from the object side along the optical axis, a front group GF including a negative meniscus lens L11 having a convex surface directed toward the object side, a negative meniscus having a convex surface directed toward the object side and the biconvex positive lens L12. The rear group GR includes a lens L13 and a positive refractive power.

  The second lens group G2 includes, in order from the object side along the optical axis, a cemented negative lens of a negative meniscus lens L21 having a concave surface facing the object side and a positive meniscus lens L22 having a concave surface facing the object side, and an object side. The lens comprises a positive meniscus lens L23 having a concave surface and a positive meniscus lens L24 having a concave surface on the object side. The positive meniscus lens L23 has a thin resin layer on the object side and has a resin surface aspherical. is there.

  The image plane I is formed on an image sensor (not shown), and the image sensor is composed of a CCD, a CMOS, or the like.

  Table 1 below lists specifications of the lens systems of the photographing lenses according to the first and second examples.

  In (surface data) in the table, the object surface is the object surface, the surface number is the surface number from the object side, r is the radius of curvature, d is the surface spacing, and nd is the refraction at the d-line (wavelength λ = 587.6 nm). The ratio, νd represents the Abbe number in the d-line (wavelength λ = 587.6 nm), (stop) represents the aperture stop S, and the image plane represents the image plane I. Note that the refractive index of air nd = 1.000 000 is omitted. Further, “∞” in the radius of curvature r column indicates a plane.

In (Aspheric data), the aspheric surface is expressed by the following equation.
X (y) = (y ² / r) / [1+ [1-κ (y ² / r ² )] ^1/2 ]
+ A4 × y ⁴ + A6 × y ⁶ + A8 × y ⁸ + A10 × y ¹⁰
Here, the height in the direction perpendicular to the optical axis is y, and the amount of displacement in the optical axis direction at the height y (the distance along the optical axis from the tangential plane of each aspheric surface to each aspheric surface) is X ( y) Let r be the radius of curvature (paraxial radius of curvature) of the reference sphere, κ be the conic coefficient, and An be the n-th aspherical coefficient. “En” represents “× 10 ⁻ⁿ ”, for example “1.234E-05” represents “1.234 × 10 ⁻⁵ ”. An aspherical surface is indicated by adding “*” to the right side of the surface number in (surface data).

  In (various data), f represents a focal length, FNO represents an F number, 2ω represents an angle of view (unit: “°”), Y represents an image height, TL represents a total length of the lens system, and Bf represents a back focus.

  (Lens group data) indicates the start surface number and end surface number of each lens group, and the focal length of the lens group.

  In all the following specification values, “mm” is generally used as the focal length f, radius of curvature r, surface interval d and other lengths, etc. unless otherwise specified, but the optical system is proportional. Even if it is enlarged or proportionally reduced, the same optical performance can be obtained. Further, the unit is not limited to “mm”, and other appropriate units may be used.

(Table 1)

(Surface data)
Surface number rd nd νd
Object ∞ ∞
1 132.7002 1.4000 1.589130 61.18
2 25.8526 9.5887
3 29.7335 5.0921 1.772500 49.61
4 -801.6732 0.1000
5 20.3542 4.6491 1.834000 37.17
6 15.3218 5.9701
7 (Aperture) ∞ 11.2452
8 -15.0395 1.5000 1.846660 23.78
9 -662.9579 4.5000 1.804000 46.58
10 -27.5128 0.6896
11 * -100.0000 0.0500 1.553890 38.09
12 -100.0000 4.3863 1.804000 46.58
13 -29.2280 0.1000
14 -289.2477 3.7290 1.804000 46.58
15 -38.0644 (Bf)
Image plane ∞

(Aspheric data)
11th surface κ = 1.0
A4 = -8.70710E-06
A6 = 5.02240E-09
A8 = -4.59940E-12
A10 = 0.00000E + 00

(Various data)
f = 36.00
FNO = 1.85
2ω = 44.1
Y = 14.20
TL = 91.49
Bf = 38.49

(Lens group data)
Group Start surface End surface Focal length 1 1 6 160.38
F 1 2 -54.77
R 3 6 42.77
2 8 15 36.59

  FIG. 2 is a coma aberration diagram with respect to the d-line (wavelength λ = 587.6 nm) in the infinitely focused state of the photographing lenses according to the first and second examples when no decentering error occurs during manufacturing. Indicates.

  FIG. 3 is a coma aberration diagram with respect to the d-line (wavelength λ = 587.6 nm) in the infinitely focused state of the photographing lenses according to the first and second embodiments when an eccentric error occurs during manufacturing. .

  In each aberration diagram, Y represents an image height (unit: “mm”), and coma aberration is shown at image heights of 10 mm, 0 mm (center), and −10 mm. The same applies to other aberration diagrams referred to in the following description.

(First embodiment)
Next, the adjusting mechanism for the taking lens according to the first embodiment will be described. In the first embodiment, in order to satisfactorily correct deterioration in imaging performance due to an eccentric error during manufacturing, position adjustment for shifting and decentering the front group GF of the first lens group G1 and tilt decentering of the first lens group G1 are performed. An adjustment mechanism for adjusting the position is provided.

  FIG. 4 is a cross-sectional view showing the mechanism of the taking lens according to the first embodiment.

  FIG. 5 is a diagram showing a mechanism for adjusting the position for shifting and decentering the front group of the first lens group of the photographing lens shown in FIG. 4 and a mechanism for adjusting the position for decentering the first lens group. It is the figure seen from the object side.

  As shown in FIG. 4, in the taking lens 1 according to the first example, the front group GF of the first lens group G1 is held by an annular first holding member 31. The rear group GR of the first lens group G1 is held by an annular second holding member 32. The second lens group G2 is held by a cylindrical third holding member 33. Further, the aperture stop S is held by an aperture stop mechanism 34 for changing the aperture diameter. The third holding member 33 and the aperture stop mechanism 34 are supported by the support member 37 by a mechanism (not shown). The support member 37 is attached to a camera body (not shown) via a mount member (not shown).

  As shown in FIGS. 4 and 5, the first holding member 31 is provided with three protrusions 31a protruding to the outer periphery, and the protrusion 31a is provided with a hole 31b. The first holding member 31 is fixed to the second holding member 32 with a screw 36 that is inserted through the hole 31b via a washer 35. Here, the diameters of the three holes 31 b are formed larger than the shaft diameter of the screw 36.

  With this configuration, the three screws 36 are loosened to adjust the position of the first holding member 31 in the direction substantially perpendicular to the optical axis of the first holding member 31, and then the screws 36 are tightened and fixed. That is, it is possible to adjust the position by shifting the front group GF of the first lens group G1 in a direction substantially orthogonal to the optical axis.

  Further, by replacing the washer 35 with a washer having a different thickness in the optical axis direction, the air gap between the front group GF and the rear group GR in the first lens group G1 can be changed, and thereby the curvature of the lens, It is possible to satisfactorily correct variations in various aberrations caused by manufacturing errors in the lens thickness and the air gap.

  The second holding member 32 is fixed to the end surface of the support member 37 at three locations by an adjustment screw 39 via a coil spring 38. The coil spring 38 urges the second holding member 32 to repel the support member 37 in the object side direction, and a spring washer or a wave washer can be used instead.

  With this configuration, the inclination of the second holding member 32 with respect to the support member 37 is adjusted by tightening or loosening the three adjustment screws 39. That is, it is possible to adjust the position of tilting the entire first lens group G1 with respect to the optical axis.

  Table 2 below lists corresponding values of conditional expressions (1), (3), and (4) in the photographing lens 1 according to the first example.

(Table 2)
(Values for conditional expressions)
(1) f1 / f = 4.46
(3) (−fF) /f=1.52
(4) (R2 + R1) / (R2-R1) = − 1.48

  FIG. 6 shows a case where the imaging performance is corrected by performing position adjustment for shifting and decentering the front group of the first lens group and position adjustment for tilt decentering of the first lens group when there is an eccentricity error during manufacturing. The coma aberration figure with respect to d line | wire (wavelength (lambda) = 587.6nm) in the infinite point focusing state of the imaging lens which concerns on one Example is shown.

  Comparing the aberration diagrams of FIGS. 2, 3, and 6, it can be seen that in FIG. 6, the deterioration of the imaging performance due to the decentration error at the time of manufacture is satisfactorily corrected from the central portion to the peripheral portion.

(Second embodiment)
Next, the adjustment mechanism for the taking lens according to the second embodiment will be described. In the second embodiment, in order to satisfactorily correct deterioration in imaging performance due to decentration error during manufacturing, position adjustment for shifting and decentering the front group GF of the first lens group G1 and tilt decentering of the second lens group G2 are performed. An adjustment mechanism for adjusting the position is provided. Parts having the same structure as the first embodiment will be described using the same reference numerals, or the same reference numerals are shown in the drawings and description thereof is omitted.

  FIG. 7 is a cross-sectional view showing the mechanism of the taking lens according to the second embodiment.

  As shown in FIG. 7, in the photographing lens 2 according to the second example, the front group GF of the first lens group G1 is held by an annular first holding member 31. The rear group GR of the first lens group G1 is held by an annular second holding member 40. The second lens group G2 is held by a cylindrical third holding member 41. Further, the aperture stop S is held by an aperture stop mechanism 34 for changing the aperture diameter. The aperture stop mechanism 34 is supported by the support member 42 by a mechanism (not shown). The support member 42 is attached to a camera body (not shown) via a mount member (not shown).

  Since the structure for fixing the first holding member 31 to the second holding member 40 is the same as that of the first embodiment, the same reference numerals are shown in FIG. By the method, the first holding member 31 can be moved and fixed in the direction perpendicular to the optical axis with respect to the second holding member 40. That is, it is possible to adjust the position of the front lens group GF of the first lens group G1 that is decentered in the direction orthogonal to the optical axis.

  Similarly to the first embodiment, the air gap between the front group GF and the rear group GR in the first lens group G1 can be changed by replacing the washer 35 with a washer having a different thickness in the optical axis direction. As a result, it is possible to satisfactorily correct variations in various aberrations caused by manufacturing errors in lens curvature, lens thickness, and air spacing.

  The second holding member 40 is fixed to the end surface of the support member 42 by three screws 43.

  The third holding member 41 is fixed at three places with an adjustment screw 45 via a coil spring 44 to a flange portion 42 a provided on the inner peripheral portion of the support member 42. The coil spring 44 urges the third holding member 41 to repel the support member 42 in the image side direction, and a spring washer or a wave washer can be used instead.

  With this configuration, the inclination of the third holding member 41 with respect to the support member 42 is adjusted by tightening or loosening the three adjustment screws 45. That is, it is possible to adjust the position by tilting the entire second lens group G2 with respect to the optical axis.

  Table 3 below lists corresponding values of conditional expressions (2), (3), and (4) in the photographic lens 2 according to the second example.

(Table 3)
(Values for conditional expressions)
(2) f2 / f = 1.02
(3) (−fF) /f=1.52
(4) (R2 + R1) / (R2-R1) = − 1.48

  FIG. 8 is a diagram illustrating a case where the imaging performance is corrected by performing position adjustment for shifting and decentering the front group of the first lens group and position adjustment for tilting and decentering the second lens group when there is an eccentricity error during manufacturing. The coma aberration figure with respect to d line (wavelength (lambda) = 587.6nm) in the infinite point focusing state of the imaging lens which concerns on 2nd Example is shown.

  Comparing the aberration diagrams of FIGS. 2, 3, and 8, it can be seen that in FIG. 8, the deterioration of the imaging performance due to the decentration error at the time of manufacture is well corrected from the central part to the peripheral part.

  As described above, according to this embodiment, it is possible to provide a low-cost photographic lens that can achieve good optical performance and an adjustment method thereof.

  Next, a camera equipped with the taking lens according to the present embodiment will be described. Although the case where the taking lens 1 according to the first embodiment is mounted will be described, the same applies to other embodiments.

  FIG. 9 is a diagram illustrating a configuration of a camera including the photographing lens according to the first example.

  In FIG. 9, a camera 63 is a digital single-lens reflex camera provided with the taking lens 1 according to the first embodiment. In the camera 63, light from an object (subject) (not shown) is collected by the taking lens 1 and focused on the focusing screen 67 through the quick return mirror 65. The light imaged on the focusing screen 67 is reflected a plurality of times in the pentaprism 69 and guided to the eyepiece lens 71. Thus, the photographer can observe the subject image as an erect image through the eyepiece lens 71.

  When the release button (not shown) is pressed by the photographer, the quick return mirror 65 is retracted out of the optical path, and light from the subject (not shown) reaches the image sensor 73. As a result, light from the subject is picked up by the image sensor 73 and recorded as a subject image in a memory (not shown). In this way, the photographer can shoot the subject with the camera 63.

  By mounting the photographic lens 1 according to the first embodiment on the camera 63, a camera having high performance can be realized.

  In addition, in order to explain the present invention in an easy-to-understand manner, the configuration requirements of the embodiment have been described, but the present invention is not limited to this.

G1 1st lens group S Aperture stop G2 2nd lens group GF Front group GR Rear group L11 Negative meniscus lens I Image plane 1, 2 Shooting lens 36 Screw 39, 45 Adjustment screw 63 Camera

Claims (10)

In order from the object side, it has a first lens group having positive refractive power and a second lens group having positive refractive power,
The first lens group includes, in order from the object side, a front group having negative refractive power and a rear group having positive refractive power,
An adjustment mechanism that performs position adjustment that shifts and decenters the front group and tilts and decenters at least one of the first lens group and the second lens group after assembling the first lens group and the second lens group; A photographic lens comprising:   The photographic lens according to claim 1, wherein the adjustment mechanism performs position adjustment for tilting the first lens group. The photographing lens according to claim 1, wherein the following condition is satisfied.
2.00 <f1 / f <8.00
However,
f1: Focal length of the first lens group f: Focal length of the photographing lens   The photographing lens according to claim 1, wherein the adjustment mechanism performs position adjustment for decentering the second lens group. The photographic lens according to claim 1, wherein the following condition is satisfied.
0.70 <f2 / f <1.40
However,
f2: focal length of the second lens group f: focal length of the photographing lens The photographing lens according to claim 1, wherein the following condition is satisfied.
1.00 <(− fF) / f <2.00
However,
fF: focal length of the front group f: focal length of the taking lens   The photographic lens according to claim 1, wherein the front group includes a negative meniscus lens having a convex surface facing the object side. The photographing lens according to claim 7, wherein the following condition is satisfied.
-1.90 <(R2 + R1) / (R2-R1) <− 1.02
However,
R1: radius of curvature of the object side surface of the negative meniscus lens R2: radius of curvature of the image side surface of the negative meniscus lens   An optical apparatus comprising the photographing lens according to claim 1. In order from the object side, it has a first lens group having positive refractive power and a second lens group having positive refractive power,
The first lens group, in order from the object side, is a method for adjusting a photographic lens including a front group having negative refractive power and a rear group having positive refractive power,
After assembling the first lens group and the second lens group, the front group is shifted decentered, and position adjustment is performed to tilt at least one of the first lens group and the second lens group. Adjustment method of the taking lens.

Images