JP3352245B2 - Zoom lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens suitable for a photographic camera, a video camera, an SV camera and the like and a camera using the zoom lens. A photographing angle of view of 58 ° to 33 °, in which the entire lens system is miniaturized by appropriately setting the lens configurations of these two lens groups.
The present invention relates to a zoom lens having a zoom ratio of about 2, and a camera using the same.

[0002]

2. Description of the Related Art A so-called negative lead type zoom lens in which a lens unit having a negative refractive power precedes the conventional one can easily obtain a long back focus and relatively easily widen the angle of view, so that it is used for a single-lens reflex camera. Is widely used for standard zoom lenses.

For example, JP-A-57-20713, JP-B-60-46688, and JP-B-61-42246.
In JP-A-5-88084 and the like, there are two lens groups, a first group having a negative refractive power and a second group having a positive refractive power, in order from the object side. There has been proposed a zoom lens in which the magnification is changed. In Japanese Patent Application Laid-Open No. 57-20713, high optical performance is obtained as a standard zoom lens over the entire zoom range by using two lenses, a negative lens and a positive lens, and one aspheric surface in the first group. ing.

Japanese Patent Publication No. 60-46888 and Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 88084 proposes a small zoom lens in which the first group includes two lenses, a negative lens and a positive lens, and the second group includes four lenses, a positive lens, a positive lens, a negative lens, and a positive lens. ing. Tokiko Sho 61-42246
The publication proposes a zoom lens in which the first group includes two lenses, a negative lens and a positive lens, and the second group includes four or five lenses.

[0005]

Generally, a negative lead type zoom lens comprising a first lens unit having a negative refractive power and a second lens unit having a positive refractive power has a relatively wide angle of view. There is a feature that a predetermined back focus can be easily obtained. However, the whole lens system
In order to configure the optical system with a small number of lenses of about 6 and to obtain good optical performance, it is necessary to appropriately set the refractive power arrangement, lens shape, and the like of each lens group. If the refractive power arrangement or the lens configuration of each lens group is inappropriate, even if the number of lenses is increased, the aberration variation accompanying zooming becomes large, and it becomes difficult to obtain high optical performance over the entire zoom range.

For example, in order to shorten the overall length of the lens while maintaining a predetermined zoom ratio, if the refractive power of each lens unit is increased, deterioration of the peripheral portion of the image on the wide-angle side, that is, in other words, aberration, in other words, curvature of field. , Astigmatism and distortion are significantly increased.

The present invention is directed to a zoom lens composed of two negative-lead type lens groups which are preceded by a lens group having a negative refractive power. By appropriately setting the lens configuration of each lens group, the total number of the six lenses can be reduced. While having a predetermined back focus with a small number of lenses,
A zoom lens having high optical performance over the entire zoom range of about ° to 33 °, an F-number of 4.3 to 5.8, and a zoom ratio of about 2, and a compact lens system, and a camera using the same. The purpose is to provide.

[0008] The zoom lens according to the first aspect of the present invention is composed of a first lens unit having a negative refractive power and a second lens unit having a positive refractive power.
The first lens unit is moved from the wide-angle end to the telephoto end by moving the first unit with a locus convex toward the image plane side.
The group is moved to the object side so as to reduce the distance between the first group and the first group. The first group has a meniscus negative eleventh lens having a convex surface facing the object side and a convex surface facing the object side. The second group includes a positive twelfth lens having a meniscus shape,
A positive twenty-first component comprising a twenty-first lens and a positive twenty-second lens
Minute, a negative 22nd component comprising a negative 23rd lens, and
The three components of the positive twenty-third component comprising the positive twenty-fourth lens
Has a focal length of the i group fi, the entire system of the focal length fw at the wide-angle end, said 12 lens on the object side and the lens surface on the image side curvature radius respectively R12a, R12b, said 11 The lens thickness of the lens is D11, the air gap between the eleventh lens and the twelfth lens is D11 and 12, the back focus at the wide angle end is Bfw, the length from the first lens surface to the last lens surface at the telephoto end is TDT , Material of the eleventh lens
Is the Abbe number of ν11 and the refractive index of the material of the 21st lens is
When N21

(Equation 3) 52 <ν11 (9) 1.65 <N21 (10)

[0009]

(Equation 3) It is characterized by satisfying certain conditions.

[0010]

1 to 5 show numerical examples 1 to 5 of the present invention, respectively.
It is a lens sectional view of. In the lens sectional view, (A)
Indicates the zoom position at the wide-angle end, (B) indicates the middle position, and (C) indicates the zoom position at the telephoto end. In the figure, L1 is the first group of negative refractive power, L2
Denotes a second group having a positive refractive power, SP denotes an aperture, FP denotes a fixed flare cut aperture, and IP denotes an image plane. Arrows indicate the movement trajectories of the respective lens units during zooming from the wide-angle end to the telephoto end. In FIG.
The second group L2 moves toward the object side while the group L1 has a locus convex toward the image plane. The first lens unit corrects the image plane fluctuation caused by zooming, and the second lens unit has zooming action.

The first lens unit L1 is composed of two lenses: a negative meniscus eleventh lens having a convex surface facing the object side and a positive meniscus twelfth lens having a convex surface facing the object side. The occurrence of various aberrations in the entire first group is reduced.

In the second lens unit L2, L21 is a positive twenty-first component, and has two lenses, a positive twenty-first lens and a positive twenty-second lens, both lens surfaces of which are convex. L22 is a negative twenty-second component, and both lens surfaces are composed of a single negative twenty-third lens having a concave surface. L23 is a positive 23rd component, which is a meniscus-shaped positive second component having a convex surface facing the image surface side.
It consists of four lenses.

By configuring the second lens unit L2 as described above, fluctuations of various aberrations due to zooming are corrected well. The stop SP is provided between the 21st lens and the 22nd lens, and moves together with the second unit with zooming. This prevents an increase in the diameter of the front lens and reduces the size of the entire lens system.

In this embodiment, the flare cut aperture FP is fixed at the time of zooming, but it may be moved integrally or independently of the second lens unit. According to this, the degree of freedom of aberration correction can be increased. Focusing is performed by moving the first group, the second group, or the entire system.

In the present invention, as described above, by specifying the lens configuration of each lens group and satisfying conditional expressions (1) to (7), good optical performance can be obtained over the entire zoom range and over the entire screen. I have.

Next, the technical meaning of each of the above conditional expressions will be described.

Conditional expression (1) relates to the refractive power of the first lens unit, and is intended to favorably correct distortion on the wide-angle side while mainly reducing the size of the entire lens system. Conditional expression (1)
If the upper limit is exceeded, the occurrence of negative distortion becomes small, but the diameter of the front lens becomes large. On the other hand, when the value exceeds the lower limit, negative distortion increases, which is not preferable.

Conditional expression (2) relates to the ratio of the refracting power of the first lens unit and the second lens unit. The image surface characteristic at the wide-angle end and the spherical aberration at the telephoto end are mainly determined while reducing the diameter of the front lens. Is to be corrected favorably. If the upper limit of conditional expression (2) is exceeded, the distance between the first and second lens units must be increased on the wide-angle side, and the amount of movement of each lens unit for increasing the diameter of the front lens and changing the magnification is reduced. The total length of the lens increases. If the lower limit is exceeded, it becomes difficult to correct curvature of field on the wide-angle side and spherical aberration on the telephoto side.

Conditional expression (3) relates to the lens shape (shape factor) of the positive twelfth lens, and is mainly for correcting spherical aberration and distortion in a well-balanced manner. When the value exceeds the upper limit of conditional expression (3), the negative distortion at the wide-angle end decreases, but a large amount of positive spherical aberration occurs on the telephoto side. If the lower limit value is exceeded, a large amount of negative distortion occurs at the wide-angle end, and it becomes difficult to correct this.

Condition (4) is a negative meniscus eleventh condition.
The lens thickness on the optical axis of the lens is set appropriately. Exceeding the upper limit will increase the outer diameter and increase the weight. On the other hand, when the value exceeds the lower limit, the durability of the lens decreases, which is not good.

In the two-unit zoom lens according to the present invention,
When the refractive powers of the first and second groups are φ1 and φ2, respectively, and the distance between the principal points of the first and second groups is e, the refractive power φ of the entire system is φ = φ1 + φ2-eφ1φ2 ‥‥‥ (a ). Here, the refractive power φ is positive, and φ1 and φ2 have different signs. Therefore, when the principal point interval e is increased when the refractive power φ is constant, it is necessary to increase φ1 or decrease φ2. The opposite is true when the principal point interval e is reduced.

In the former case, in order to reduce various aberrations in each lens group, it is preferable that the first group of optical systems is made of a glass material having a high refractive index and the second group of optical systems is made of a glass material having a low refractive index. However, since optical glass materials have a distribution of high refractive index and high dispersion and low refractive index and low dispersion, it is difficult to correct chromatic aberration if the above glass materials are selected.

On the other hand, in the latter case, although the selection of the glass material is advantageous, the change in the height at which the marginal ray of the axial light beam passes through the first and second optical systems becomes small. For this reason, it becomes difficult to correct spherical aberration particularly at the telephoto end.

In view of the above points, the conditional expression (5) appropriately sets the distance D11 between the meniscus negative eleventh lens and the meniscus positive twelfth lens of the first group. If the value exceeds the upper limit or the lower limit of (5), it becomes difficult to correct chromatic aberration and spherical aberration on the telephoto side.

In the two-unit zoom lens system according to the present invention, if the back focus is set too long, the refractive power of the first and second units will increase, and the lenses of each lens unit will be corrected in a well-balanced manner. It is necessary to increase the number of lenses, and as a result, it is difficult to reduce the size of the entire lens system.

Conditional expression (6) is used as a two-unit zoom lens.
For example, this is for properly correcting various aberrations while appropriately setting the back focus at the wide-angle end so as to have a back focus of a length applicable to a single-lens reflex camera or the like.

In the case of the two-unit zoom lens according to the present invention, the total lens thickness (the length from the first lens surface to the last lens surface) becomes minimum at the telephoto end. Although the total thickness of the lens includes the air gap, it largely depends on the axial thickness of each lens. Generally, as the axial thickness of the lens increases, the strength increases, but the weight increases and the size increases. Conversely, when the axial thickness is small, manufacturing becomes difficult.

In view of the above, the conditional expression (7) appropriately sets the total thickness of the lens at the telephoto end and effectively reduces the size of the entire lens system.

Conditional expression (9) is an expression for the material of the eleventh lens.
Set the number of beams appropriately to reduce axial and lateral chromatic aberrations associated with
This is for good correction and deviates from conditional expression (9).
This makes it difficult to correct these chromatic aberrations properly.
come. Conditional expression (10) defines the refractive index of the material of the twenty-first lens.
Appropriately set, good correction of field curvature mainly in the zoom range
It is for doing. If conditional expression (10) is not satisfied,
The Tuvalu sum increases and the zoom range from the middle to the telephoto end
Field curvature increases and the astigmatic difference at the telephoto side
Is not good because it gets bigger. In the present invention,
The lens configuration of the first and second groups appropriately
Zoom with a simple configuration including a wide angle of view with a zoom ratio of about 2.
Lens, but over the entire zoom range, and
A zoom lens with high optical performance over the entire screen
To obtain, satisfy at least one of the following items
Is good.

[0030]

(Equation 4) In the present invention, a zoom lens having a simple configuration including a wide angle of view with a zoom ratio of about 2 is obtained by appropriately setting the lens configurations of the first and second groups as described above. In order to obtain a zoom lens having high optical performance over the zoom range and over the entire screen, at least one of the following items should be satisfied.

[0031] ◎ is to satisfy D22,23 / fw <0.03 ··· (8 ) becomes a condition when the D22,23 the air gap between the first lens 22 and the 23 lens.

The zoom lens according to the present invention uses a so-called triplet type refractive power arrangement in which the second lens unit includes positive, negative and positive components. Here, when focusing on the light-incident surface of the second group, that is, the positive 21st component, the position of the marginal ray of the axial ray is high in the entire region from the wide-angle end to the telephoto end. It will be difficult. Therefore, by dividing the positive 21st component into two positive lenses, reasonable refraction is achieved. Further, if the number of lenses is further increased, it becomes difficult to satisfactorily correct the field curvature due to the decrease in Petzval sum.

The positive 21st component and the negative 22nd component in the second lens unit
The air gap between the components is preferably a so-called marginal contact, in which the position sensitivity is easily obtained because the sensitivity of movement of the focus surface is very high.

In view of the above, conditional expression (8)
The air gap between the first component and the negative twenty-second component is appropriately set, and if this condition is not satisfied, the marginal contact diameter increases and the size of the lens increases, which is not good. In terms of aberration correction, it is more preferable to set the numerical condition of conditional expression (8) as follows.

D22,23 / fw <0.02 (8a)

[0036]

[0037]

[0038]

The twenty-fourth lens has a meniscus shape with the convex surface facing the image surface side, and the radii of curvature of the object-side and image-side lens surfaces of the twenty-fourth lens are R24a and R24b, respectively.
And when

[0040]

(Equation 5) Satisfying the following conditions.

In the two-unit zoom lens system according to the present invention, which is preceded by a lens unit having a negative refractive power, the first unit is a negative eleventh lens unit.
It consists of two lenses, a lens and a positive twelfth lens. For this reason, the load on the negative eleventh lens is increased as compared with the case where the first group of the two-unit zoom lens is constituted by three lenses of negative, negative and positive lenses, and negative distortion occurs at the wide-angle end. More and more.

Generally, the eleventh lens is a meniscus negative lens having a convex surface facing the object side to reduce the amount of off-axis aberrations, particularly negative distortion on the wide-angle side.
Forcibly trying to satisfactorily correct distortion has a bad influence on spherical aberration, lateral chromatic aberration and the like. Therefore, in the present invention, the positive 24th lens closest to the image plane in the second group is set to the conditional expression (1).
By making the lens shape satisfying 1), the distortion at this time is favorably corrected.

In general, distortion is likely to occur more frequently in a lens where an off-axis light beam passes through a position distant from the optical axis. In the case of the lens type of the present invention, the second lens unit closest to the image plane in the second unit
In the four lenses, the off-axis light beam passes through the position farthest from the optical axis. This twenty-fourth lens is a positive lens having a shape satisfying conditional expression (11), and the distortion which is insufficiently corrected in the first lens group is satisfactorily corrected. If the upper limit of conditional expression (11) is exceeded, negative distortion will be insufficiently corrected. If the lower limit is exceeded, spherical aberration will be overcorrected.

For aberration correction, it is more preferable to set the numerical condition of the conditional expression (11) as follows.

[0045]

(Equation 6) Next, numerical examples of the present invention will be described. In the numerical examples, R
i is the radius of curvature of the i-th lens surface in order from the object side, D
i is the i-th lens thickness and air gap from the object side, Ni
And νi are the refractive index and Abbe number of the glass of the i-th lens in order from the object side. Table 1 shows the relationship between the above-described conditional expressions and various numerical values in the numerical examples. (Numerical Example 1) f = 39.33 to 73.34 Fno = 4.32 to 5.88 2ω = 57.6 ° to 32.9 ° R 1 = 116.40 D 1 = 1.50 N 1 = 1.63853 ν 1 = 55.4 R 2 = 19.42 D 2 = 6.63 R 3 = 21.34 D 3 = 2.20 N 2 = 1.74076 ν 2 = 27.8 R 4 = 27.44 D 4 = Variable R 5 = 28.72 D 5 = 2.35 N 3 = 1.71999 ν 3 = 50.3 R 6 = -144.60 D 6 = 1.85 R 7 = Aperture D 7 = 3.27 R 8 = 26.03 D 8 = 2.69 N 4 = 1.62299 ν 4 = 58.1 R 9 = -400.64 D 9 = 0.50 R10 = -41.11 D10 = 2.88 N 5 = 1.80518 ν 5 = 25.4 R11 = 22.80 D11 = 3.69 R12 = -65.52 D12 = 1.65 N 6 = 1.76182 ν 6 = 26.5 R13 = -23.40 D13 = Variable R14 = ∞ (flare cut aperture)

[0046]

[Table 1] (Numerical Example 2) f = 39.33 to 73.34 Fno = 4.32 to 5.88 2ω = 57.6 ° to 32.9 ° R 1 = 140.29 D 1 = 1.50 N 1 = 1.62299 ν 1 = 58.1 R 2 = 19.35 D 2 = 6.31 R 3 = 21.43 D 3 = 2.20 N 2 = 1.76181 ν 2 = 26.6 R 4 = 27.74 D 4 = Variable R 5 = 27.90 D 5 = 2.35 N 3 = 1.71299 ν 3 = 53.8 R 6 = -131.57 D 6 = 1.85 R 7 = Aperture D 7 = 2.74 R 8 = 24.97 D 8 = 2.43 N 4 = 1.62299 ν 4 = 58.1 R 9 = -70659.3 D 9 = 0.51 R10 = -44.71 D10 = 2.89 N 5 = 1.80518 ν 5 = 25.4 R11 = 21.74 D11 = 4.01 R12 = -66.78 D12 = 1.65 N 6 = 1.78471 ν 6 = 25.7 R13 = -24.32 D13 = Variable R14 = ∞ (flare cut aperture)

[0047]

[Table 2] (Numerical Example 3) f = 39.33 to 73.34 Fno = 4.32 to 5.88 2ω = 57.6 ° to 32.9 ° R 1 = 147.18 D 1 = 1.50 N 1 = 1.60311 ν 1 = 60.7 R 2 = 19.43 D 2 = 6.66 R 3 = 21.33 D 3 = 2.20 N 2 = 1.72824 ν 2 = 28.5 R 4 = 27.32 D 4 = Variable R 5 = 28.40 D 5 = 2.40 N 3 = 1.71299 ν 3 = 53.8 R 6 = -126.88 D 6 = 1.90 R 7 = Aperture D 7 = 1.81 R 8 = 22.94 D 8 = 2.85 N 4 = 1.60562 ν 4 = 43.7 R 9 = 2446.23 D 9 = 0.46 R10 = -51.41 D10 = 2.95 N 5 = 1.80518 ν 5 = 25.4 R11 = 20.09 D11 = 4.60 R12 = -76.64 D12 = 1.65 N 6 = 1.69894 ν 6 = 30.1 R13 = -24.23 D13 = Variable R14 = ∞ (Flare cut aperture)

[0048]

[Table 3] (Numerical Example 4) f = 39.33 to 73.34 Fno = 4.31 to 5.88 2ω = 57.6 ° to 32.8 ° R 1 = 137.26 D 1 = 1.50 N 1 = 1.60311 ν 1 = 60.7 R 2 = 19.86 D 2 = 7.76 R 3 = 21.47 D 3 = 2.20 N 2 = 1.63979 ν 2 = 34.5 R 4 = 27.20 D 4 = Variable R 5 = 28.40 D 5 = 2.45 N 3 = 1.70153 ν 3 = 41.2 R 6 = -116.31 D 6 = 2.20 R 7 = Aperture D 7 = 2.38 R 8 = 25.40 D 8 = 2.20 N 4 = 1.62299 ν 4 = 58.1 R 9 = -122.99 D 9 = 0.43 R10 = -37.93 D10 = 2.60 N 5 = 1.80518 ν 5 = 25.4 R11 = 22.03 D11 = 4.70 R12 = -47.70 D12 = 1.65 N 6 = 1.74076 ν 6 = 27.8 R13 = -21.56 D13 = Variable R14 = ∞ (flare cut aperture)

[0049]

[Table 4] (Numerical Example 5) f = 39.30 to 73.70 Fno = 4.27 to 5.88 2ω = 57.7 ° to 32.7 ° R 1 = 136.35 D 1 = 1.50 N 1 = 1.60311 ν 1 = 60.7 R 2 = 19.56 D 2 = 7.58 R 3 = 21.26 D 3 = 2.20 N 2 = 1.67270 ν 2 = 32.1 R 4 = 26.90 D 4 = Variable R 5 = 27.79 D 5 = 2.50 N 3 = 1.70153 ν 3 = 41.2 R 6 = -115.11 D 6 = 1.39 R 7 = Aperture D 7 = 1.25 R 8 = 21.89 D 8 = 3.00 N 4 = 1.60311 ν 4 = 60.7 R 9 = -239.55 D 9 = 0.44 R10 = -48.88 D10 = 3.00 N 5 = 1.76182 ν 5 = 26.5 R11 = 17.82 D11 = 4.64 R12 = -48.06 D12 = 1.80 N 6 = 1.69894 ν 6 = 30.1 R13 = -22.42 D13 = Variable R14 = ∞ (flare cut aperture)

[0050]

[Table 5]

[0051]

[Table 6]

[0052]

As described above, according to the present invention, in a zoom lens composed of two negative-lead type lens groups which are preceded by a lens group having a negative refractive power, the lens configuration of each lens group is appropriately set. Accordingly, while having a predetermined back focus with a small number of lenses such as 6 as a whole, a shooting angle of view of 58 ° to 33 °, and an F-number of 4.3 to
It is possible to achieve a zoom lens having high optical performance over the entire zoom range of about 5.8 and a zoom ratio of about 2, and miniaturizing the entire lens system, and a camera using the same.

[Brief description of the drawings]

FIG. 1 is a sectional view of a lens according to a numerical example 1 of the present invention.

FIG. 2 is a sectional view of a lens according to a numerical example 2 of the present invention.

FIG. 3 is a sectional view of a lens according to a numerical example 3 of the present invention.

FIG. 4 is a sectional view of a lens according to a numerical example 4 of the present invention.

FIG. 5 is a sectional view of a lens according to a numerical example 5 of the present invention.

FIG. 6 is an aberration diagram at a wide-angle end according to Numerical Embodiment 1 of the present invention.

FIG. 7 is an intermediate aberration diagram of the numerical example 1 of the present invention.

FIG. 8 is an aberration diagram at a telephoto end in Numerical Example 1 of the present invention;

FIG. 9 is an aberration diagram at a wide-angle end according to Numerical Example 2 of the present invention.

FIG. 10 is a diagram showing aberrations in the middle of the numerical example 2 of the present invention.

FIG. 11 is an aberration diagram at a telephoto end in Numerical Example 2 of the present invention.

FIG. 12 is an aberration diagram at a wide angle end according to Numerical Example 3 of the present invention.

FIG. 13 is an intermediate aberration diagram of the numerical example 3 of the present invention.

FIG. 14 is an aberration diagram at a telephoto end in Numerical Example 3 of the present invention.

FIG. 15 is an aberration diagram at a wide angle end according to Numerical Example 4 of the present invention.

FIG. 16 is an intermediate aberration diagram of the numerical example 4 of the present invention.

FIG. 17 is an aberration diagram at a telephoto end in Numerical Example 4 of the present invention.

FIG. 18 is an aberration diagram at a wide angle end according to Numerical Example 5 of the present invention.

FIG. 19 is an intermediate aberration diagram of the numerical example 5 of the present invention.

FIG. 20 is an aberration diagram at a telephoto end in Numerical Example 5 of the present invention.

[Explanation of symbols]

 L1 First lens group L2 Second lens group SP stop FP flare cut stop IP image plane dd line gg line S sagittal image plane M meridional image plane C sine condition

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 15/16

Claims (4)

(57) [Claims] 1. A lens system comprising, in order from the object side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. The second group is moved toward the object side such that the distance from the first group is reduced, and the first group is directed toward the object side. The second group includes a positive eleventh lens and a positive twenty- second lens, and comprises a negative meniscus eleventh lens and a positive meniscus twelfth lens having a convex surface facing the object side.
A positive 21st component consisting of a negative 23rd lens
A positive twenty-second component comprising a positive twenty-fourth lens
It has three components of 23 components, and the focal length of the ith group is f
i, the focal length at the wide-angle end of the entire system is fw, the radii of curvature of the lens surfaces of the twelfth lens on the object side and the image plane side are R12a,
R12b, the lens thickness of the eleventh lens is D11, the first lens is
The air gap between the first lens and the twelfth lens is D11, 12,
The back focus at the wide-angle end is Bfw, and the length from the first lens surface to the final lens surface at the telephoto end is TD.
T , the Abbe number of the material of the eleventh lens is ν11;
When the refractive index of the material of one lens is N21 A zoom lens characterized by satisfying the following condition: 52 <ν11 1.65 <N21 . 2. The space between the 22nd lens and the 23rd lens.
2. The zoom lens according to claim 1, wherein a condition of D22,23 / fw <0.03 is satisfied when the air gap is D22,23 . 3. The twenty-fourth lens has a meniscus shape having a convex surface facing the image surface side, and the object surfaces and the image surface side of the twenty-fourth lens have curvature radii of R24a and R24b, respectively.
[Equation 2] 3. The zoom lens according to claim 1 , wherein the following condition is satisfied. 4. A camera comprising the zoom lens according to claim 1.