JP3733164B2 - Macro lens - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a macro lens suitable for a camera having an autofocus function such as a photographic camera, a video camera, and an electronic still camera, and more particularly, from an object at infinity to an object at a short distance (photographing magnification: 1.0 ×). The present invention relates to a medium telephoto macro lens having a high angle of view of about 14 degrees and an F number of about 3.5, in which aberration correction is well performed when focusing on a wide range of objects.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a so-called macro lens or micro lens (hereinafter referred to as “macro lens”) as a photographing lens mainly intended for photographing a short distance object in a photographic camera, a video camera, an electronic still camera, and the like.
[0003]
Of these, a macro lens for a 35 mm single-lens reflex camera is often configured to be able to shoot at a wide range of object distances from an infinitely distant object to a close object with an imaging magnification of 1x or 0.5x.
[0004]
The macro lens is designed so as to obtain high optical performance particularly in a short distance object as compared with other photographing lenses such as a general standard lens and a telephoto lens. In many cases, the macro lens is used not only for a short distance object but also for a wide range of objects ranging from a short distance object to an infinite object.
[0005]
In general, when an attempt is made to expand the object distance range (imaging magnification range) in a macro lens, fluctuations in aberration associated with focus increase. For example, when the photographing magnification is increased, spherical aberration is insufficiently corrected, and a large amount of outward coma occurs.
[0006]
On the other hand, Japanese Patent Application Laid-Open No. 55-140810 comprises three lens groups of positive, negative, and positive refractive power in order from the object side, from an object at infinity. A macro lens has been proposed in which the first lens group is moved to the object side and the second lens group is moved to the image plane side when focusing on an object at a close distance, thereby favorably correcting aberration fluctuations associated with the focus.
[0007]
In Japanese Patent Application No. 4-124480, in order from the object side, the first group of positive refractive power, the first group of positive refractive power, the second group of negative refractive power, and the third group of positive refractive power. A macro lens having a configuration in which the second group is moved to the image side and the first a group is moved to draw a convex arc toward the object side during focusing from an object at infinity to a short distance object is proposed. ing.
[0008]
[Problems to be solved by the invention]
Since the macro lens can be photographed at a wide range of object distances, the amount of movement (movement amount) of the focusing lens is larger than that of a general photographing lens. In addition, as the focal length of the entire system increases, the amount of focusing lens that is fed out increases proportionally and the lens weight of the focusing lens group tends to increase.
[0009]
For example, taking an imaging lens (macro lens) of the entire extension system as a focus method, for example, when focusing on a subject having the same shooting magnification with a shooting lens having the same F number focal length of 100 mm and a focal length of 200 mm, shooting with a focal length of 200 mm The lens is doubled with respect to the photographing lens having a focal length of 100 mm, and the lens weight is considerably increased.
[0010]
In recent years, in an autofocus system camera that has been actively developed, such an increase in the focus feed amount and the lens weight has become a very big problem in realizing high-speed autofocus.
[0011]
Further, when the photographing magnification range is enlarged in the macro lens, especially when the magnification is enlarged to the higher magnification, the aberration fluctuation increases with the change of the photographing magnification, and it becomes very difficult to correct this well.
[0012]
As described above, in the macro lens, it is a big problem to satisfactorily correct various aberrations while reducing the lens weight of the focusing lens group and reducing the lens extension amount.
[0013]
In the present invention, mainly by appropriately setting the lens configuration and the distribution of refractive power, the present invention can be applied to a wide range of object distances from an infinite object to a close object, particularly an imaging magnification of approximately 1.0 times. An object of the present invention is to provide a medium telephoto macro lens having a high optical performance with an F number of about 3.5 suitable for an autofocus camera, in which aberration fluctuations at the time of focusing are well corrected.
[0014]
[Means for Solving the Problems]
Macro lens of the present invention includes, in order from the object side, the 1a lens unit of positive refractive power, a 1b lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power, and a The lens group includes only four groups, and the first group b includes , in order from the object side , only a meniscus negative first b1 lens having a concave surface on the image plane side and a positive first b2 lens as lenses . upon focusing from infinity to a close object, the second group is moved toward the image side, a further macro lens moving either the third group or the fourth group, said 1a group When the combined focal length of the first lens group and the first lens group is f1, the focal length of the first lens group is f1b, and the refractive power of the lens surface on the image surface side of the first lens lens is φ, 1.4 <| φ | · f1 < 2.6 (1)
2 <f1b / f1 <15 (2)
It is characterized by satisfying the following conditions.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
1 to 6, 9, and 10 are lens cross-sectional views of Numerical Examples 1 to 8 of the present invention, and FIGS. 7, 8, and 11 are lens cross-sectional views of Reference Examples 1 to 3, respectively. FIGS. 12 to 35 and FIGS. 44 to 51 are aberration diagrams of Numerical Examples 1 to 8 of the present invention.
36 to 43 and FIGS. 52 to 55 are aberration diagrams of Reference Examples 1 to 3. FIG.
In the aberration diagrams, an object at infinity and photographing magnifications of 0.1x, 0.5x, and 1.0x are shown in order .
[0016]
In the lens cross-sectional view, L1a is a first group of positive refractive power, L1b is a first group of positive refractive power, L2 is a second group of negative refractive power, L3 is a third group of positive refractive power, and L4. Is a fourth group having positive or negative refractive power, and SP is a stop, which is disposed between the second group L2 and the third group L3.
[0017]
In each embodiment, the first group 1b is configured to have a meniscus negative first b1 lens and a positive first b2 lens having a concave surface facing the image plane side. When focusing from an infinitely distant object to a close object, the second lens unit L2 is moved to the image plane side as indicated by an arrow. The third lens unit L3 is moved to the object side as necessary, but may be fixed.
[0018]
In the present embodiment, as described above, the lens configuration is specified, and the refractive power of the lens surface on the image surface side of the first b group, the first group, and the first b1 lens is expressed by the conditional expressions (1) and (2). Thus, aberration variation due to a change in photographing magnification is reduced, and good aberration correction can be performed for a wide range of objects ranging from an object at infinity to a near object. In particular, good aberration correction is possible for a wide range of objects ranging from an object at infinity to a short distance object with a photographing magnification of 1.0.
[0019]
Next, features of aberration correction of the macro lens of the present invention will be described. In the macro lens according to the present invention, focusing is performed over a wide range of object distance, and fluctuations of various aberrations accompanying the focusing at this time will be described using the paraxial refractive power arrangement of FIG.
[0020]
FIG. 56 shows three of the four lens groups constituting the macro lens of the present invention: a first refractive power 1a group L1a, a positive refractive power first b group L1b, and a negative refractive power second group L2. It is explanatory drawing which showed the optical path state when a lens group is extracted and a light ray passes through this lens system.
[0021]
FIG. 56 (A) shows a state in which an object at infinity is focused, and FIG. 56 (B) shows a state in which the second lens unit L2 is moved to the image plane side as shown by an arrow and focused on a short-distance object. . As described above, since the macro lens has a photographing range with a wide object distance, various aberrations are liable to occur during focusing. In particular, the basic spherical aberration tends to be significantly insufficiently corrected. This will be described with reference to the passage diagram of the axial light beam in FIG.
[0022]
First, in the focused state on the object at infinity in FIG. 56 (A), it is assumed that the spherical aberration as the combined system from the first a group L1a group to the second group L2 is in a corrected state. The internal cancellation state is that a negative spherical aberration occurs in the first lens unit L1a and the first lens unit L1b having a positive refractive power and a negative spherical aberration occurs in the second lens unit having a negative refractive power. Correct with good balance by canceling each other.
[0023]
However, in the in-focus state with respect to the short-distance object in FIG. 56 (B), the second group L2 moves to the image plane side, so the incident height of the axial light beam into the second group becomes low. For this reason, the amount of positive spherical aberration generated from the second lens unit L2 is reduced.
[0024]
As a result, the spherical aberration tends to be remarkably insufficiently corrected in the combined system of the first group L1a to the second group L2. Therefore, in the macro lens having such a lens configuration, in order to prevent the spherical aberration from being significantly undercorrected during focusing, the negative aberration of the second group of spherical aberration is reduced as the subject distance becomes shorter. It is necessary to configure the spherical aberration to be displaced in the positive direction in the combined system of the first group 1a and the first group 1b so as to cancel the displacement.
[0025]
Therefore, in the present invention, the 1b group is configured to include a meniscus negative lens (first b1 lens) and a positive lens (first b2 lens) having concave surfaces directed in order from the object side to the image side, thereby increasing spherical aberration. It is displaced in the positive direction.
[0026]
In other words, paying attention to the incidence height to the 1b lens group axial rays becomes higher in the short-distance focusing state in FIG. 56 (B) than the infinity in-focus state in FIG. 56 (A), it The spherical aberration is largely displaced in the positive direction mainly on the lens surface on the image side of the meniscus-shaped negative lens disposed there. The subsequent positive lens is used especially to maintain the first group b as a positive refractive power as a whole. When this positive lens is removed, the share of the positive refractive power of the 1a group increases, making it difficult to correct various aberrations in the 1a group, and at the same time, on the image plane side of the meniscus negative lens. The curvature of the lens surface becomes loose, and the effect of displacement of spherical aberration in the positive direction is weakened. Further, when a meniscus negative lens and a positive lens are cemented, they are separated because the effect of displacement of spherical aberration in the positive direction is weakened.
[0027]
The macro lens of the present invention has a lens configuration as described above, and thereby corrects aberration fluctuations during focusing, particularly spherical aberration fluctuations.
[0028]
Next, the technical meaning of the above conditional expression will be described. Conditional expression (1) relates to the refractive power of the image surface side lens surface of the negative meniscus first b1 lens with the concave surface facing the image surface side in the first group 1b, and the entire system when mainly focusing on a short distance object This is a condition for suppressing the aberration fluctuations of the entire system by efficiently displacing the fluctuations of these aberrations, in particular, the negative aberration of the spherical aberration in the positive direction on the lens surface.
[0029]
When the divergent action of the lens surface increases beyond the upper limit of conditional expression (1), the spherical aberration is greatly displaced in the positive direction when focusing on a close object, and is corrected in the focused state on the close object. It is not good because it becomes excessive. If the divergent action of the lens surface is weakened beyond the lower limit of conditional expression (1), the amount of displacement in the positive direction of spherical aberration becomes smaller when focusing on a close object, and the near object In the in-focus state, correction is insufficient, which is not good.
[0030]
In the present invention, it is more preferable that the conditional expression (1) is 1.8 <| φ | · f1 <2.1 (φ <0) (1a)
It is good to do.
[0031]
Next, Conditional Expression (2) relates to the focal length in the 1b group, in which the refractive power sharing between the 1a group and the 1a group and the 1b group in the combined system (first group) is appropriate. This is a condition for satisfactorily suppressing fluctuations in various aberrations. If the upper limit of conditional expression (2) is exceeded and the positive refractive power of the 1b group is weakened, the share of the positive refractive power of the 1a group increases, resulting in spherical aberration and coma in the 1a group. Therefore, it becomes difficult to correct various aberrations such as astigmatism and field curvature. In particular, when focusing on a short-distance object, the variation in spherical aberration occurring in the first group a is greatly displaced in the negative direction by the action of the essential positive refractive power of the first group, and is removed in the subsequent first group b. It ’s not good because it ca n’t be done.
[0032]
If the lower limit of the conditional expression (2) is exceeded and the positive refractive power sharing of the 1b group is weakened, it becomes easier to correct aberrations in the 1a group, but the balance of various aberrations occurring in the 1b group is balanced. In addition, the displacement amount in the positive direction of spherical aberration during focusing is reduced in the entire first group 1b, and correction is insufficient in a focused state with a short-distance object.
[0033]
In the lens configuration as described above, the refractive power of each lens group is set as in the conditional expressions (1) and (2), so that an object at infinity can be changed to a short distance object with a photographing magnification of about 1.0. Aberration variation is reduced for a wide range of objects, and good optical performance is obtained.
[0034]
In the present invention, it is preferable to satisfy at least one of the following conditions in order to further reduce aberration fluctuations during focusing and obtain good optical performance over the entire object distance.
[0035]
First, the focal length of the aforementioned first group a is
(A1) 1.05 <f1a / f1 <1.74 when the focal length of the 1a group is f1a (3)
It is good to do. More preferably 1.10 <f1a / f1 <1.45 (3a)
It is good to do.
[0036]
(A2) The first group a having a positive lens whose convex surfaces are convex in order from the object side, a meniscus negative lens having a concave surface facing the object side, and a meniscus positive lens having a convex surface facing the object side In this case, it is only necessary to satisfactorily correct fluctuations in various aberrations during focusing, particularly high-order flare fluctuations of color spherical aberration.
[0037]
(A3) The first lens group in the order from the object side is a positive lens, both lens surfaces are convex positive lenses, a meniscus negative lens having a concave surface facing the object side, and a meniscus positive lens having a convex surface facing the object side In this case, the variation of various aberrations including spherical aberration can be corrected more satisfactorily.
[0038]
(A4) The 1a group includes, in addition to the lens configuration described above, a meniscus negative lens having a convex surface directed toward the object side, a positive lens, and a meniscus positive lens having a convex surface directed toward the object side, in order from the object side. Even if it has the structure which has, it is good because the fluctuation | variation of various aberrations can be corrected comparatively favorable.
[0039]
So-called floating may be employed in which the second group is moved during focusing and the other lens groups are moved at different speeds relative to the second group.
[0040]
That is,
(A5) It is preferable to move the third group when focusing from an object at infinity to an object at a short distance. It is particularly preferable to move the third group to the object side.
[0041]
(A6) It is preferable to move the fourth group during focusing from an infinitely distant object to a close object. In particular, the fourth lens group has a positive refractive power, and is preferably moved with a convex locus on the image plane side when focusing from an object at infinity to a near object.
[0042]
(A7) It is preferable to move the first b group during focusing from an infinitely distant object to a close object. In particular, it is preferable to move the first group b toward the image plane side (Reference Example 3) .
[0043]
In the present invention, any of these lens groups can be moved to obtain a floating effect, and in particular, fluctuations in the image plane at the intermediate shooting distance can be corrected more satisfactorily.
[0044]
In particular, when focusing in (A5), if the third group is moved to the object side in the opposite direction to the second group,
(A8) It is preferable to set the lens weight and the movement amount substantially equal to each other so that the lens weight is canceled out in the upward shooting and the downward shooting, and a stable lens driving speed can be obtained.
[0045]
(A9) The second group preferably includes a negative lens having a concave surface directed toward the image surface side in order from the object side, and a cemented lens in which a negative lens L2n having both concave surfaces and a positive lens are cemented. .
[0046]
Among these, when the refractive index and Abbe number of the material of the negative lens L2n having concave lens surfaces are N2n and ν2n, respectively.
[Expression 1]
It is good to do. According to this, it is possible to satisfactorily correct the residual chromatic aberration, particularly axial chromatic aberration, of the combined system of the first group a and the first group b.
[0048]
(A10) 0.15 <| f2 | / f <0.45 (f2) where f2 is the focal length of the second lens unit and f is the focal length of the entire system when focusing on an infinitely distant object in the entire system <0) (5)
It is good to do.
[0049]
If the negative refractive power of the second group becomes weaker than the upper limit value of conditional expression (5), it becomes easier to correct aberrations, but this is not good because the amount of movement of the second group increases during focusing. Conversely, when the negative refractive power increases beyond the lower limit, various aberrations occurring in the second group increase, and at the same time, the positive refractive power of the combined system of the first group 1a and the first group 1b increases, and the generated aberrations also increase. This is not good because it increases and various aberrations in the entire lens system deteriorate.
[0050]
(A11) The third group preferably includes a positive lens having a convex surface facing the object side, and a cemented lens in which a positive lens L3p having a convex surface facing the object side and a negative lens are cemented. Especially when the refractive index and Abbe number of the material of the positive lens L3p of the laminated lens are N3p and ν3p.
[Expression 2]
It is good to do. This is preferable because chromatic aberration, particularly axial chromatic aberration, can be corrected satisfactorily.
[0052]
(A12) The fourth group preferably includes a meniscus negative lens having a convex surface directed toward the image surface side and a positive lens having a convex surface directed toward the object side. Alternatively, the fourth group may include a positive lens, a meniscus negative lens having a convex surface facing the image surface side, and a positive lens having a convex surface facing the object side. This is effective in correcting off-axis aberrations, particularly coma and astigmatism.
[0053]
(A13) The diaphragm may be integrated with the second group or integrated with the third group, but it may be configured with a mechanism that is relatively easy to fix and arrange between the second group and the third group.
[0054]
Then the numerical examples 1 to 8 of the present invention showing a numerical example of Example 1-3. In numerical examples, ri is the radius of curvature of the i-th lens surface in order from the object side, di is the i-th lens thickness and air spacing in order from the object side, and ni and νi are the i-th lens in order from the object side. The refractive index and Abbe number of the glass. Table 1 shows the relationship between the conditional expressions described above and the numerical values in the numerical examples.
[0055]
The aspherical shape is the X axis in the optical axis direction, the H axis in the direction perpendicular to the optical axis, the light traveling direction is positive, R is the paraxial radius of curvature, and A, B, C, D and E are the aspheric coefficients. [0056]
[Equation 3]
It is expressed by the following formula.
[0057]
[Outside 1]
[0058]
[Outside 2]
[0059]
[Outside 3]
[0060]
[Outside 4]
[0061]
[Outside 5]
[0062]
[Outside 6]
[0063]
[Expression 1]
[0064]
[Expression 2]
[0065]
[Equation 3]
[0066]
[Expression 4]
[0067]
[Equation 5]
[0068]
[Table 1]
[0069]
【The invention's effect】
As described above, according to the present invention, by appropriately setting the configuration of the entire lens system, in particular, the configuration of the focusing lens group, the imaging magnification from the object at infinity to the object at a short distance, especially the imaging magnification is 1.0 times. A medium telephoto lens having a high optical performance of about F-number 3.5, particularly suitable for an autofocus camera, in which aberration fluctuations are corrected well when focusing on a wide range of object distances to the vicinity. Macro lens can be achieved.
[Brief description of the drawings]
1 is a lens cross-sectional view of Numerical Example 1 of the present invention. FIG. 2 is a lens cross-sectional view of Numerical Example 2 of the present invention. FIG. 3 is a lens cross-sectional view of Numerical Example 3 of the present invention. Lens Cross-sectional View of Numerical Example 4 of the Invention FIG. 5 Lens Cross-sectional View of Numerical Example 5 of the Invention FIG. 6 Lens Cross-sectional View of Numerical Example 6 of the Invention FIG. 7 Reference Example 1 of the Invention FIG. 8 is a lens sectional view of Reference Example 2 of the present invention. FIG. 9 is a lens sectional view of Numerical Example 7 of the present invention. FIG. 10 is a lens sectional view of Numerical Example 8 of the present invention. 11 is a lens cross-sectional view of Reference Example 3 of the present invention. FIG. 12 is an aberration diagram for an infinite object of Numerical Example 1 of the present invention. FIG. 13 is an imaging magnification of 0.1 × of Numerical Example 1 of the present invention. FIG. 14 is an aberration diagram when the photographing magnification is 0.5 × according to Numerical Example 1 of the present invention. FIG. 15 is a numerical value according to the present invention. FIG. 16 is an aberration diagram for an object at infinity according to Numerical Example 2 of the present invention. FIG. 17 is an imaging magnification of 0.1 according to Numerical Example 2 of the present invention. FIG. 18 is an aberration diagram at the photographing magnification of 0.5x in Numerical Example 2 of the present invention. FIG. 19 is an aberration diagram at the photographing magnification of 1.0x in Numerical Example 2 of the present invention. FIG. 20 is an aberration diagram for an object at infinity according to Numerical Example 3 of the present invention. FIG. 21 is an aberration diagram at a photographing magnification of 0.1 × according to Numerical Example 3 of the present invention. FIG. 23 is an aberration diagram when the imaging magnification is 0.5x in Example 3. FIG. 23 is an aberration diagram when the imaging magnification is 1.0x according to Numerical Example 3. FIG. 24 is infinity according to Numerical Example 4 according to the present invention. FIG. 25 is an aberration diagram when an object is used. FIG. 25 is an aberration diagram when the photographing magnification is 0.1 × in Numerical Example 4 of the present invention. FIG. 27 is an aberration diagram of the numerical example 4 when the photographing magnification is 0.5 ×. FIG. 27 is an aberration diagram of the numerical example 4 of the present invention when the photographing magnification is 1.0 ×. FIG. 28 is an infinite number of the numerical example 5 of the present invention. Aberration diagram for a distant object. FIG. 29 is an aberration diagram for Numerical Example 5 of the present invention at a photographing magnification of 0.1x. FIG. 30 is an aberration diagram of Numerical Example 5 of the present invention at a photographing magnification of 0.5x. FIG. 31 is an aberration diagram of the numerical example 5 of the present invention when the photographing magnification is 1.0 ×. FIG. 32 is an aberration diagram of the numerical example 6 of the present invention when the object is at infinity. FIG. 34 is an aberration diagram of the numerical example 6 when the photographing magnification is 0.1 ×. FIG. 34 is an aberration diagram of the numerical example 6 of the present invention when the photographing magnification is 0.5 ×. FIG. 35 is an image of the numerical example 6 of the present invention. aberration diagram when an object at infinity aberration diagram Figure 36 reference example 1 at a magnification 1.0x Figure 37 shooting multiple of reference example 1 Aberration diagram Figure 40 Reference Example when the aberration diagram 38 shows aberration chart at the Reference Example 1 imaging magnification 0.5x [39] Reference Example 1 imaging magnification 1.0x when the 0.1x aberration chart at the photographing magnification 0.5x aberration diagrams Figure 42 reference example 2 in the case of 2 infinite aberration chart at the distant object [41] photographing magnification 0.1x reference example 2 [Figure 43] photographing magnification 0 of numerical example 7 of the aberration diagrams Figure 45 the present invention when the numerical infinite object of example 7 of the aberration diagrams FIG. 44 the present invention when the shooting magnification 1.0x reference example 2. aberration chart at the aberration diagrams photographing magnification 1.0x numerical example 7 of the aberration chart at the photographing magnification 0.5x numerical example 7 of FIG. 46 the present invention Figure 47 the present invention when the 1x photographing magnification 0.1 of numerical example 8 of the aberration diagram when an object at infinity in the numerical value example 8 of FIG. 48 the present invention Figure 49 the invention Aberration chart at the aberration diagrams photographing magnification 1.0x numerical example 8 of the aberration chart at the photographing magnification 0.5x numerical example 8 of FIG. 50 the present invention Figure 51 the present invention when the [ Figure 52] aberration when the aberration diagram FIG. 53 is aberration chart at the photographing magnification 0.1x of reference example 3 [Figure 54] photographing magnification 0.5x of example 3 when an object at infinity reference example 3 FIG. 55 is an aberration diagram of the reference example 3 when the photographing magnification is 1.0 ×. FIG. 56 is an explanatory diagram of a paraxial refractive power arrangement of the macro lens of the present invention.

Claims (13)

In order from the object side, the 1a lens unit of positive refractive power, a 1b lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power, and only the fourth group as a lens unit The first group 1b has, in order from the object side, a meniscus negative first b1 lens and a positive first b2 lens having a concave surface directed toward the image surface side as a lens, and a short distance object from an infinite object. upon focusing on the second group is moved toward the image side, further, a macro lens moving either the third group or the fourth group, the synthesis focal said 1a group and group the 1b When the distance is f1, the focal length of the first b group is f1b, and the refractive power of the lens surface on the image plane side of the first b1 lens is φ, 1.4 <| φ | · f1 <2.6
2 <f1b / f1 <15
A macro lens characterized by satisfying the following conditions. When the focal length of the first group a is f1a, 1.05 <f1a / f1 <1.74
The macro lens according to claim 1, wherein the following condition is satisfied. The 1a group, in order from the object side, a positive lens of both lens surfaces is convex, the negative lens shaped meniscus with a concave surface directed toward the object side, and as only the lens meniscus-like positive lens having a convex surface directed toward the object side The macro lens according to claim 2, wherein the macro lens is provided.   4. The macro lens according to claim 2, wherein the third group is moved during focusing from an object at infinity to a near object.   5. The macro lens according to claim 4, wherein the third group is moved toward the object side when focusing from an object at infinity to an object at a short distance.   4. The macro lens according to claim 2, wherein the fourth group is moved during focusing from an object at infinity to an object at a short distance.   7. The macro according to claim 6, wherein the fourth group has a positive refractive power, and has a convex locus on the image plane side during focusing from an object at infinity to a near object. lens. The second group comprises, in order from the object side, that has a negative lens having a concave surface on the image side, only the cemented lens obtained by cementing a negative lens and a positive lens of which both surfaces are concave as a lens The macro lens according to claim 1 or 2, characterized in that: The third group includes, in order from the object side, that has a positive lens with a convex surface on the object side, only the joined cemented lens of a positive lens and a negative lens having a convex surface directed toward the object side as a lens The macro lens according to claim 1 or 2, characterized in that: The fourth group includes , in order from the object side, a meniscus negative lens having a concave surface directed toward the object side and a positive lens having a convex surface directed toward the object side as lenses. Or 2 macro lenses. The fourth group comprises, in order from the object side, a positive lens, and characterized in that it has a meniscus shape negative lens having a concave surface facing toward the object side, only the positive lens having a convex surface directed toward the object side as a lens The macro lens according to claim 1 or 2. The first group a includes , in order from the object side, a positive lens, a positive lens whose convex surfaces are convex, a meniscus negative lens with a concave surface facing the object side, and a meniscus positive lens with a convex surface facing the object side only macro lens according to claim 2, it characterized in that it has a as a lens. The first group a has , in order from the object side, a meniscus negative lens having a convex surface facing the object side, a positive lens, and a meniscus positive lens having a convex surface facing the object side as lenses. The macro lens according to claim 2.