High magnification zoom lens

Abstract

A high magnification zoom lens includes, in order from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and an L lens group having a positive refractive power and positioned closest to an image side. When zooming from the wide angle end to the telephoto end, the interval between the lens groups changes, the third lens group is composed of a 3A lens group of positive refractive power and a 3B lens group of negative refractive power for image blur correction, the fourth lens group is composed of a 4A lens group of positive refractive power and a 4B lens group of negative refractive power, and the fifth lens group is composed of a fourth lens group of positive refractive power and a fifth lens group of negative refractive power. The 4B lens group is moved from the object side to the image side to perform a focusing operation from an infinity state to a close distance.

Description

Technical Field

[0001] The present invention is suitable for use in a high-magnification zoom lens having a zoom ratio exceeding approximately 15 times, which is used in an imaging lens for an imaging device such as a digital camera or a video camera. Background Art

[0002] In recent years, zoom lenses used in imaging devices have been required to have high zoom ratios, high resolutions, and compact systems. In particular, high-magnification zoom lenses are required to have wider angles and longer telephoto lenses in order to capture a wide variety of scenes without changing lenses.

[0003] Furthermore, in the telephoto range in particular, it is required to have a mechanism for preventing image blurring caused by vibrations of the optical system due to hand shaking or the like.

[0004] Furthermore, rapid autofocus driving is required.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-12243 Patent Document 2: WO2021 / 131370

[0006] Patent Document 1 discloses a zoom lens that has a large field of view with a half angle of view of approximately 40 degrees at the wide-angle end, is compact, and includes an image blur prevention mechanism.

[0007] However, the zoom ratio is only about 4x, which poses a problem, especially when increasing the focal length at the telephoto end.

[0008] Patent Document 2 discloses a zoom lens having a focal length of approximately 400 mm at the telephoto end.

[0009] However, the zoom ratio is only about 4x, which poses a problem in increasing the field of view, especially at the wide-angle end. Furthermore, the overall length is large. Summary of the Invention

[0010] The present invention provides an optical system having a high zoom ratio of approximately 15 times or more, with various aberrations well corrected, high performance, and compact size.

[0011] In order to solve the above-mentioned problems, the present invention is a high-magnification zoom lens characterized in that it has a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and an Lth lens group GL with positive refractive power and located closest to the image side, which are arranged in order from the object side. When the magnification is changed from the wide-angle end to the telephoto end, the intervals between the lens groups change, and the third lens group G3 changes from a positive refractive power group G1 to a negative refractive power group G2. The fourth lens group G4 is composed of a 3A lens group G3A with positive refractive power and a 3B lens group G3B with negative refractive power, and image blur correction is performed by moving the 3B lens group G3B in a direction approximately perpendicular to the optical axis. The fourth lens group G4 is composed of a 4A lens group G4A with positive refractive power and a 4B lens group G4B with negative refractive power, and focusing action from an infinity state to a close distance is performed by moving the 4B lens group G4B in the direction of the optical axis from the object side to the image side. The high-magnification zoom lens satisfies the following conditional formula. (1)0.25<f1 / fT<0.66 (2) 0.35<|ff / fr|<0.80 f1: focal length of the first lens group G1 fT: The focal length of the entire high-magnification zoom lens at infinity at the telephoto end ff: The combined focal length of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end fr: The combined focal length from the third lens group G3 to the Lth lens group GL at infinity at the wide-angle end Effects of the Invention

[0012] According to the present invention, it is possible to provide an optical system having a high zoom ratio of approximately 15 times or more, in which various aberrations are well corrected, and which is high-performance and compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a lens configuration diagram at infinity at the wide-angle end according to Example 1 of the high-magnification zoom lens of the present invention. Figure 2 These are diagrams showing longitudinal aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 1. Figure 3 These are diagrams showing longitudinal aberrations at infinity and at an intermediate focal length of the high-magnification zoom lens of Example 1. Figure 4 These are diagrams showing longitudinal aberrations at infinity at the telephoto end of the high-magnification zoom lens of Example 1. Figure 5 These are diagrams showing lateral aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 1. Figure 6These are diagrams showing lateral aberrations at infinity and at an intermediate focal length of the high-power zoom lens of Example 1. Figure 7 These are diagrams showing lateral aberrations at infinity at the telephoto end of the high-power zoom lens of Example 1. Figure 8 These are diagrams showing lateral aberrations when a 0.3-degree skew angle is corrected for the high-magnification zoom lens of Example 1 at infinity at the wide-angle limit during vibration reduction. Figure 9 This is a diagram showing lateral aberrations when a skew angle of 0.3 degrees is corrected during vibration reduction at infinity and an intermediate focal length of the high-power zoom lens of Example 1. Figure 10 These are diagrams showing lateral aberrations when a 0.3-degree skew angle is corrected for the high-power zoom lens of Example 1 at the telephoto end and at infinity during vibration isolation. Figure 11 This is a lens configuration diagram at infinity at the wide-angle end according to Example 2 of the high-magnification zoom lens of the present invention. Figure 12 These are diagrams showing longitudinal aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 2. Figure 13 These are diagrams showing longitudinal aberrations at infinity and at an intermediate focal length of the high-magnification zoom lens of Example 2. Figure 14 These are diagrams showing longitudinal aberrations at infinity at the telephoto end of the high-magnification zoom lens of Example 2. Figure 15 This is a diagram showing lateral aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 2. Figure 16 This is a diagram showing lateral aberrations at infinity at an intermediate focal length of the high-magnification zoom lens of Example 2. Figure 17 This is a diagram showing lateral aberrations at infinity at the telephoto end of the high-magnification zoom lens of Example 2. Figure 18 These are diagrams showing lateral aberrations of the high-power zoom lens of Example 2 at infinity at the wide-angle limit during vibration reduction with a 0.3-degree skew angle corrected. Figure 19 These are diagrams showing lateral aberrations when a skew angle of 0.3 degrees is corrected during vibration reduction at infinity and at an intermediate focal length of the high-power zoom lens of Example 2. Figure 20 These are diagrams showing lateral aberrations of the high-power zoom lens of Example 2 at the telephoto end at infinity during vibration reduction with a 0.3-degree skew angle corrected. Figure 21 This is a lens configuration diagram at infinity at the wide-angle end according to Example 3 of the high-magnification zoom lens of the present invention. Figure 22These are diagrams showing longitudinal aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 3. Figure 23 These are diagrams showing longitudinal aberrations at infinity and at an intermediate focal length of the high-magnification zoom lens of Example 3. Figure 24 These are diagrams showing longitudinal aberrations at infinity at the telephoto end of the high-magnification zoom lens of Example 3. Figure 25 These are diagrams showing lateral aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 3. Figure 26 This is a diagram showing lateral aberrations at infinity at an intermediate focal length of the high-magnification zoom lens of Example 3. Figure 27 This is a diagram showing lateral aberrations at infinity at the telephoto end of the high-magnification zoom lens of Example 3. Figure 28 These are diagrams showing lateral aberrations of the high-power zoom lens of Example 3 at infinity at the wide-angle limit during vibration reduction with a 0.3-degree skew angle corrected. Figure 29 This is a diagram showing lateral aberrations when a skew angle of 0.3 degrees is corrected during vibration reduction at infinity and an intermediate focal length of the high-power zoom lens of Example 3. Figure 30 These are diagrams showing lateral aberrations of the high-power zoom lens of Example 3 at the telephoto end at infinity during vibration reduction and with a 0.3-degree skew angle corrected. Figure 31 This is a lens configuration diagram at infinity at the wide-angle end according to Example 4 of the high-magnification zoom lens of the present invention. Figure 32 These are diagrams showing longitudinal aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 4. Figure 33 This is a diagram showing longitudinal aberrations at infinity at an intermediate focal length of the high-magnification zoom lens of Example 4. Figure 34 These are diagrams showing longitudinal aberrations at infinity at the telephoto end of the high-magnification zoom lens of Example 4. Figure 35 These are diagrams showing lateral aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 4. Figure 36 This is a diagram showing lateral aberrations at infinity at an intermediate focal length of the high-magnification zoom lens of Example 4. Figure 37 This is a diagram showing lateral aberrations at infinity at the telephoto end of the high-magnification zoom lens of Example 4. Figure 38 These are diagrams showing lateral aberrations of the high-power zoom lens of Example 4 when the lens is at the wide-angle limit and at infinity with anti-vibration and a 0.3-degree skew angle corrected. Figure 39This is a diagram showing lateral aberrations when a skew angle of 0.3 degrees is corrected during vibration reduction at infinity and an intermediate focal length of the high-power zoom lens of Example 4. Figure 40 These are diagrams showing lateral aberrations of the high-power zoom lens of Example 4 at the telephoto end at infinity during vibration reduction with a 0.3-degree skew angle corrected. Figure 41 This is a lens configuration diagram at infinity at the wide-angle end according to Example 5 of the high-magnification zoom lens of the present invention. Figure 42 These are diagrams showing longitudinal aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 5. Figure 43 These are diagrams showing longitudinal aberrations at infinity and at an intermediate focal length of the high-magnification zoom lens of Example 5. Figure 44 These are diagrams showing longitudinal aberrations at infinity at the telephoto end of the high-magnification zoom lens of Example 5. Figure 45 These are diagrams showing lateral aberrations at infinity at the wide-angle limit of the high-magnification zoom lens of Example 5. Figure 46 This is a diagram showing lateral aberrations at infinity at an intermediate focal length of the high-magnification zoom lens of Example 5. Figure 47 These are diagrams showing lateral aberrations at infinity at the telephoto end of the high-magnification zoom lens of Example 5. Figure 48 These are diagrams showing lateral aberrations of the high-power zoom lens of Example 5 when the lens is at the wide-angle limit and at infinity with anti-vibration and a 0.3-degree skew angle corrected. Figure 49 This is a diagram showing lateral aberrations of the high-power zoom lens of Example 5 at infinity at an intermediate focal length during vibration reduction with a 0.3-degree skew angle corrected. Figure 50 These are diagrams showing lateral aberrations of the high-power zoom lens of Example 5 at the telephoto end at infinity during vibration reduction and with a 0.3-degree skew angle corrected. DETAILED DESCRIPTION

[0014] Hereinafter, embodiments of the high-power zoom lens according to the present invention will be described in detail. The following embodiments describe an example of the high-power zoom lens according to the present invention, and the present invention is not limited to these embodiments without departing from the spirit and scope of the present invention.

[0015] As Figure 1 、 Figure 11 、 Figure 21 、 Figure 31 、 Figure 41As can be seen from the lens structure diagram shown, the high-power zoom lens of the present invention is characterized in that it has, arranged in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and an Lth lens group GL with positive refractive power and located closest to the image side. When the high-power zoom lens is zoomed from the wide-angle end to the telephoto end, the intervals between the lens groups change, and the third lens group G3 The high-magnification zoom lens is composed of a 3A lens group G3A with positive refractive power and a 3B lens group G3B with negative refractive power, and image blur correction is performed by moving the 3B lens group G3B in a direction approximately perpendicular to the optical axis. The fourth lens group G4 is composed of a 4A lens group G4A with positive refractive power and a 4B lens group G4B with negative refractive power, and focusing action from an infinity state to a close distance is performed by moving the 4B lens group G4B in the direction of the optical axis from the object side to the image side. The high-magnification zoom lens satisfies the following conditional formula. (1)0.25<f1 / fT<0.66 (2) 0.35<|ff / fr|<0.80 f1: focal length of the first lens group G1 fT: The focal length of the entire high-magnification zoom lens at infinity at the telephoto end ff: The combined focal length of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end fr: The combined focal length from the third lens group G3 to the Lth lens group GL at infinity at the wide-angle end

[0016] As an optical system for achieving a high zoom ratio, zoom lenses are generally known. These lenses consist of, arranged in order from the object side, a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, and multiple rear lens groups, with the rear lens group including a group for focusing. Furthermore, a zoom lens disclosed in Patent Document 1, for example, includes a partial group for image blur correction within the third lens group, thereby miniaturizing the optical system.

[0017] Furthermore, in a zoom lens typically consisting of a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, and multiple rear lens groups, arranged in this order from the object side, axial light rays in the third lens group pass through a high position throughout the entire zoom range, resulting in significant spherical aberration or coma in the third lens group. Therefore, the high-power zoom lens of the present invention, by employing a configuration comprising a third lens group G3 with positive refractive power that varies with zooming, and a fourth lens group G4 with positive refractive power, can minimize spherical aberration and coma throughout the entire zoom range, thereby minimizing aberrations in the optical system as a whole.

[0018] Conditional expression (1) defines the ratio of the focal length of the first lens group G1 to the focal length of the entire system in the infinite focus state at the telephoto end.

[0019] If the upper limit of conditional expression (1) is exceeded and the refractive power of the first lens group G1 decreases, the converging effect of light emitted from the first lens group G1 decreases, and the diameter of the second lens group G2 increases, resulting in an increase in the size of the optical system, which is not preferable.

[0020] If the lower limit of the conditional expression (1) is exceeded and the refractive power of the first lens group G1 increases, spherical aberration and coma aberration will increase mainly at the telephoto end, which is not preferable.

[0021] In order to ensure the effect of conditional expression (1), it is preferable to further set the upper limit value to 0.55 and the lower limit value to 0.32.

[0022] Conditional equation (2) specifies the ratio of the combined focal length of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end to the combined focal length of the third lens group G3 through the L-th lens group GL at infinity at the wide-angle end. In order to achieve a large field of view at the wide-angle end while miniaturizing the entire system, it is necessary to appropriately set the retrofocus power configuration at the wide-angle end.

[0023] If the upper limit of conditional expression (2) is exceeded and the combined refractive power of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end becomes weak, it will be difficult to widen the entire system while keeping the total optical length short. Furthermore, if the upper limit of conditional expression (2) is exceeded and the combined refractive power of the third lens group G3 to the L-th lens group GL at infinity at the wide-angle end becomes strong, it will be difficult to reduce spherical aberration or coma.

[0024] If the lower limit of conditional expression (2) is exceeded and the combined refractive power of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end becomes stronger, it will be difficult to reduce astigmatism at the wide-angle end. In addition, the rising effect of the on-axis light emitted from the second lens group G2 becomes stronger, and the diameter of the third lens group G3 and beyond becomes larger, which is not preferable. Furthermore, if the lower limit of conditional expression (2) is exceeded and the combined refractive power of the third lens group G3 to the L-th lens group GL at infinity at the wide-angle end becomes weaker, the total length becomes longer, which is not preferable.

[0025] In order to ensure the effect of conditional expression (2), it is preferable to further set the upper limit value to 0.70 and the lower limit value to 0.45.

[0026] Another feature of the present invention is that the distance between the 4A lens group G4A and the 4B lens group G4B in the infinite state is constant during zooming.

[0027] By making the distance between lens group 4A G4A and lens group 4B G4B constant during zooming, mechanisms such as the cam can be simplified, and the product can be miniaturized. Furthermore, since the so-called zoom tracking state for maintaining focus on the subject during zooming at infinity is achieved, rapid and stable focusing can be achieved.

[0028] Another feature of the present invention is that the interval between the 3A lens group G3A and the 3B lens group G3B is constant during zooming.

[0029] By making the distance between the 3A lens group G3A and the 3B lens group G3B constant, mechanisms such as cams can be simplified and the product can be miniaturized.

[0030] Another feature of the present invention is that each of the 3B lens groups G3B is a cemented lens consisting of a positive lens and a negative lens.

[0031] If the weight of the lens group driven during vibration control increases, the actuator required for driving it will also be large, leading to a large-scale mechanism. In order to simultaneously achieve good aberration correction during vibration control and miniaturization of the mechanism, the number of lenses used in the 3B lens group G3B needs to be suppressed to a minimum. By constituting the 3B lens group G3B with one positive lens and one negative lens, it is possible to suppress the chromatic aberration of magnification generated when the 3B lens group G3B is moved in a direction roughly perpendicular to the optical axis. In addition, by setting it as a cemented lens, there is no need to produce mechanical elements such as spacers, thereby achieving further weight reduction.

[0032] Another feature of the present invention is that the 4B lens group G4B is a negative lens, or a cemented lens consisting of a positive lens and a negative lens.

[0033] To achieve both rapid focusing and compactness, the lens group used in focusing needs to be lightweight. By making the 4B lens group G4B a single negative lens or a cemented lens consisting of a positive lens and a negative lens, the weight of the 4B lens group G4B can be kept low.

[0034] Another feature of the present invention is that the Lth lens group GL located closest to the image side is fixed relative to the image plane.

[0035] By making the Lth lens group GL located closest to the image side fixed relative to the image plane, mechanisms such as cams can be simplified, and the product can be miniaturized.

[0036] Another feature of the present invention is that the first lens group G1 is composed of one negative lens and two positive lenses arranged in order from the object side.

[0037] To achieve both high imaging performance and compactness, the optimal configuration is required to minimize the number of elements in the first lens group G1 while also correcting aberrations. By including both a negative lens and a positive lens, lateral chromatic aberration occurring in the first lens group G1 can be suppressed. Furthermore, by using two positive lenses, spherical aberration and coma, which primarily occur in the first lens group G1 at the telephoto end, can be minimized.

[0038] Another feature of the present invention is that the 4A lens group G4A includes at least two positive lenses and one negative lens.

[0039] Since the axial light in the 4A lens group G4A passes through a high position from the wide-angle end to the telephoto end, large spherical aberration or coma is generated in the 4A lens group G4A. Since the aberration generated in the 4A lens group G4A is magnified in the 4B lens group G4B having a negative refractive power, it is necessary to suppress the aberration generated in the 4A lens group G4A in order to correct each aberration well from the infinity state to the close distance. Therefore, by constituting the 4A lens group G4A with at least two positive lenses, the spherical aberration or coma in the entire system can be well corrected. In addition, by including a positive lens and a negative lens in the 4A lens group G4A, the axial chromatic aberration in the entire system can be well corrected.

[0040] Another feature of the present invention is that the following conditional expression is satisfied. (3)0.60<|f4B / f4|<1.80 f4B: focal length of the 4B lens group G4B f4: focal length of the fourth lens group G4

[0041] Conditional expression (3) defines the ratio of the focal length of the 4B lens group G4B to the focal length of the 4th lens group G4.

[0042] If the upper limit of conditional expression (3) is exceeded and the refractive power of lens group 4B G4B decreases, the movement distance of lens group 4B G4B during focusing becomes longer, making it impossible to perform rapid focusing action, which is not preferred. On the other hand, if the upper limit of conditional expression (3) is exceeded and the refractive power of lens group 4B G4 increases, it becomes difficult to suppress astigmatism.

[0043] If the lower limit of conditional expression (3) is exceeded and the refractive power of the 4B lens group G4B increases, it becomes difficult to suppress the astigmatism generated in the 4B lens group G4B, and the variation of astigmatism from the infinite distance state to the close distance state becomes larger, which is not preferable. In addition, if the lower limit of conditional expression (3) is exceeded and the refractive power of the fourth lens group G4 becomes smaller, the divergence of the off-axis light emitted from the fourth lens group G4 becomes larger, thereby increasing the diameter of the lens group closer to the image side than the fourth lens group G4, and the optical system becomes larger.

[0044] In order to ensure the effect of conditional expression (3), it is preferable that the upper limit value be 1.60 and the lower limit value be 0.85.

[0045] Another feature of the present invention is that the following conditional expression is satisfied. (4)0.08<FB / LT<0.20 FB: Back focus distance in air conversion at wide angle LT: Total optical length at wide angle

[0046] Conditional equation (4) specifies the ratio of the air-equivalent back focus at the wide-angle end to the total optical length at the wide-angle end. Here, the back focus is the distance on the optical axis from the top of the lens surface closest to the image side of the Lth lens group GL to the image plane. By appropriately setting the back focus, the entire system can be miniaturized.

[0047] If the upper limit of conditional expression (4) is exceeded and the back focus at the wide-angle end increases, it becomes difficult to keep the total length of the optical system short, which is not preferable.

[0048] If the lower limit of conditional expression (4) is exceeded and the back focus at the wide-angle end becomes smaller, the angle of off-axis light emitted from the Lth lens group GL to the image plane becomes larger, and the peripheral light amount decreases, which is not preferable.

[0049] In order to ensure the effect of conditional expression (4), it is preferable to further set the upper limit value to 0.18 and the lower limit value to 0.09.

[0050] Another feature of the present invention is that the following conditional expression is satisfied. (5)0.50<f3 / f4<5.00 f3: focal length of the third lens group G3 f4: focal length of the fourth lens group G4

[0051] Conditional expression (5) defines the ratio of the focal length of the third lens group G3 to the focal length of the fourth lens group G4.

[0052] In the third lens group G3 and the fourth lens group G4, both on-axis and off-axis rays pass through high positions within the lens from the wide-angle to telephoto ends. Therefore, in order to achieve optimal correction of aberrations such as spherical aberration, coma, and astigmatism while miniaturizing the optical system, it is important to appropriately set the refractive power of each group.

[0053] If the upper limit of conditional expression (5) is exceeded and the refractive power of the third lens group G3 decreases, the converging effect of the light rays emitted from the third lens group G3 becomes weaker, and the diameter of the fourth lens group G4 becomes larger, making it difficult to reduce the diameter of the product. Furthermore, if the upper limit of conditional expression (5) is exceeded and the refractive power of the fourth lens group G4 increases, it becomes difficult to suppress astigmatism.

[0054] If the lower limit of conditional expression (5) is exceeded and the refractive power of the third lens group G3 becomes larger, it will be difficult to properly correct spherical aberration or coma. Furthermore, if the lower limit of conditional expression (5) is exceeded and the refractive power of the fourth lens group G4 becomes smaller, the divergence of off-axis light rays emitted from the fourth lens group G4 becomes larger, and thus the diameter of the lens group closer to the image side than the fourth lens group G4 becomes larger, and the optical system becomes larger.

[0055] In order to ensure the effect of conditional expression (5), it is preferable that the upper limit value be 4.00 and the lower limit value be 1.00.

[0056] Another feature of the present invention is that the following conditional expression is satisfied. (6)0.010<ΔPgF_3A<0.073 ΔPgF_3A: The maximum anomalous dispersion of the g-line and F-line anomalous dispersions of the positive lens included in the 3A lens group G3A

[0057] Conditional expression (6) specifies the maximum value of the anomalous dispersion properties of the positive lens included in the 3A lens group G3A at the g-line and the F-line. In addition, the anomalous dispersion of each lens included in the imaging optical system in the present invention is defined by the following formula. ΔPgF=PgF-0.64833+0.00180*νd ΔPgF: Anomalous dispersion of the lens included in the imaging optical system PgF: Partial dispersion ratio between the g-line and F-line of the lens included in the imaging optical system νd: Abbe number in d-line of the lens included in the imaging optical system

[0058] If the upper limit of conditional expression (6) is exceeded and the anomalous dispersion of the positive lens included in the 3A lens group G3A becomes large, the correction of the secondary spectrum becomes excessive, making it difficult to properly correct the axial chromatic aberration from the wide-angle end to the telephoto end, which is not preferable.

[0059] If the lower limit of conditional expression (6) is exceeded and the anomalous dispersion of the positive lens included in the 3A lens group G3A becomes small, the secondary spectrum becomes insufficiently corrected, which is not preferable.

[0060] In order to ensure the effect of conditional expression (6), it is preferable to further set the upper limit value to 0.058 and the lower limit value to 0.020.

[0061] Another feature of the present invention is that the following conditional expression is satisfied. (7)0.010<ΔPgF_1<0.073 ΔPgF_1: The maximum anomalous dispersion of the g-line and F-line anomalous dispersion of the positive lens included in the first lens group G1

[0062] Conditional expression (7) defines the maximum value of the anomalous dispersion of the positive lens included in the first lens group G1 at the g-line and the F-line.

[0063] If the upper limit of the conditional expression (7) is exceeded and the anomalous dispersion of the positive lens included in the first lens group G1 becomes large, no suitable glass types are available.

[0064] If the lower limit of conditional expression (7) is exceeded and the anomalous dispersion of the positive lens included in the first lens group G1 becomes small, correction of the secondary spectrum becomes insufficient mainly at the telephoto end, which is not preferable.

[0065] In order to ensure the effect of conditional expression (7), it is preferable to further set the upper limit value to 0.058 and the lower limit value to 0.020.

[0066] Next, the lens configuration of an embodiment of the high-power zoom lens of the present invention will be described. In the following description, the lens configuration will be described in order from the object side to the image side.

[0067] In [Surface Data], the surface number is the number of the lens surface or aperture stop S counted from the object side, r is the radius of curvature of each surface, d is the interval between each surface, nd is the refractive index with respect to the d-line (wavelength 587.56nm), vd is the Abbe number with respect to the d-line, and PgF is the partial dispersion ratio related to the g-line (wavelength 435.8nm) and F-line (wavelength 486.1nm).

[0068] The * (asterisk) attached to the surface number indicates that the lens surface shape is aspherical. Also, BF represents the back focus.

[0069] The "(Stop)" appended to the surface number indicates the position of the aperture stop S. The radius of curvature relative to the plane or the aperture stop S is indicated by ∞ (infinity).

[0070] The values of the coefficients that define the aspheric shape of the lens surface marked with an * in the [Surface Data] section are shown in [Aspheric Surface Data]. Regarding the aspheric surface shape, the coordinates are expressed as follows: y represents the displacement perpendicular to the optical axis from the optical axis, z represents the displacement perpendicular to the optical axis from the intersection of the aspheric surface and the optical axis, r represents the radius of curvature of the reference sphere, K represents the conic coefficient, and A4, A6, ..., A12 represent the 4th, 6th, ..., and 12th order aspheric coefficients, respectively.

[0071] [Various Data] shows values such as the zoom ratio and the focal length in each focal length state.

[0072] The variable interval data shows the variable interval and BF value in each focal length state.

[0073] [Lens Group Data] shows the number of the surface closest to the object side of each lens group and the composite focal length of the entire group.

[0074] Furthermore, in the aberration diagrams corresponding to the respective examples, d, g, and C represent the d-line, g-line, and C-line, respectively, and ΔS and ΔM represent the sagittal image plane and the meridional image plane, respectively.

[0075] In addition, in all the following specifications, unless otherwise specified, the focal length f, curvature radius r, lens surface spacing d, and other lengths are described in millimeters (mm). However, in the optical system, the same optical performance can be achieved even when the scale is enlarged or reduced, so this is not limited to this.

[0076] In addition, in the lens structure diagrams of each embodiment, arrows indicate the trajectory of the lens group when zooming from the wide-angle end to the telephoto end, I indicates the image plane, and the dotted line passing through the center indicates the optical axis. [Example 1]

[0077] Figure 1 This is a lens configuration diagram of a high-magnification zoom lens according to Example 1 of the present invention.

[0078] Example 1 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, an aperture stop S, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and a fifth lens group G5 with positive refractive power. Furthermore, the third lens group G3 consists of, in order from the object side, the 3A lens group G3A with positive refractive power and the 3B lens group G3B with negative refractive power. Furthermore, the fourth lens group G4 consists of, in order from the object side, the 4A lens group G4A with positive refractive power and the 4B lens group G4B with negative refractive power. Furthermore, when correcting image blur during vibration reduction, the 3B lens group G3B moves in a direction approximately perpendicular to the optical axis. Furthermore, when focusing from infinity to close distances, the 4B lens group G4B moves toward the image plane. Furthermore, the fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0079] The first lens group G1 consists of, arranged in order from the object side, a negative meniscus lens with its convex surface facing the object side, a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0080] The second lens group G2 consists of, arranged in order from the object side, a negative meniscus lens with its convex surface facing the object side, a cemented lens consisting of a biconcave lens and a biconvex lens, and a negative meniscus lens with its convex surface facing the image side.

[0081] The third lens group G3 is composed of the following lens groups arranged in sequence from the object side: 3A lens group G3A, which is composed of a double convex lens and a cemented lens composed of a double convex lens and a double concave lens; and 3B lens group G3B, which is composed of a cemented lens composed of a positive meniscus lens with the convex surface facing the image side and a double concave lens.

[0082] The 4th lens group G4 is composed of the following lens groups arranged in sequence from the object side: the 4A lens group G4A, which is composed of a biconvex lens, a biconcave lens and a biconvex lens; the 4B lens group G4B, which is composed of a cemented lens consisting of a positive meniscus lens with the convex surface facing the image side and a biconcave lens.

[0083] The fifth lens group G5 is composed of a negative meniscus lens with its convex surface facing the object side and a biconvex lens, which are arranged in this order from the object side.

[0084] Furthermore, in the high-power zoom lens of Example 1, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Furthermore, the fifth lens group G5 remains fixed relative to the image plane during zooming.

[0085] The following lists various specifications of the high-magnification zoom lens of Example 1. Numerical Example 1 Unit: mm [surface data] [Aspherical surface data] [Various data] [Variable interval data] [Lens group data] [Example 2]

[0086] Figure 11 This is a lens configuration diagram of a high-magnification zoom lens according to Example 2 of the present invention.

[0087] Example 2 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, an aperture stop S, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and a fifth lens group G5 with positive refractive power. Furthermore, the third lens group G3 consists of, in order from the object side, the 3A lens group G3A with positive refractive power and the 3B lens group G3B with negative refractive power. Furthermore, the fourth lens group G4 consists of, in order from the object side, the 4A lens group G4A with positive refractive power and the 4B lens group G4B with negative refractive power. Furthermore, when correcting image blur during vibration reduction, the 3B lens group G3B moves in a direction approximately perpendicular to the optical axis. Furthermore, when focusing from infinity to close distances, the 4B lens group G4B moves toward the image plane. Furthermore, the fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0088] The first lens group G1 consists of, arranged in order from the object side, a negative meniscus lens with its convex surface facing the object side, a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0089] The second lens group G2 is composed of, arranged in order from the object side, a negative meniscus lens with its convex surface facing the object side, a biconcave lens, and a cemented lens consisting of a biconvex lens and a negative meniscus lens with its convex surface facing the image side.

[0090] The third lens group G3 is composed of the following lens groups arranged in sequence from the object side: 3A lens group G3A, which is composed of a double convex lens and a cemented lens composed of a double convex lens and a double concave lens; and 3B lens group G3B, which is composed of a cemented lens composed of a positive meniscus lens with the convex surface facing the image side and a double concave lens.

[0091] The 4th lens group G4 is composed of the following lens groups arranged in sequence from the object side: the 4A lens group G4A, which is composed of a double convex lens, a cemented lens composed of a double convex lens and a double concave lens, and a double convex lens; and the 4B lens group G4B, which is composed of a cemented lens composed of a positive meniscus lens with the convex surface facing the image side and a double concave lens.

[0092] The fifth lens group G5 is composed of a negative meniscus lens with its convex surface facing the object side and a biconvex lens, which are arranged in this order from the object side.

[0093] Furthermore, in the high-power zoom lens of Example 2, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Furthermore, the fifth lens group G5 remains fixed relative to the image plane during zooming.

[0094] The following lists various specifications of the high-magnification zoom lens of Example 2. Numerical Example 2 Unit: mm [Surface data] [Aspherical surface data] [Various data] [Variable interval data] [Lens group data] [Example 3]

[0095] Figure 21 This is a lens configuration diagram of a high-magnification zoom lens according to Example 3 of the present invention.

[0096] Example 3 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, an aperture stop S, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and a fifth lens group G5 with positive refractive power. Furthermore, the third lens group G3 consists of, in order from the object side, the 3A lens group G3A with positive refractive power and the 3B lens group G3B with negative refractive power. Furthermore, the fourth lens group G4 consists of, in order from the object side, the 4A lens group G4A with positive refractive power and the 4B lens group G4B with negative refractive power. Furthermore, when correcting image blur during vibration reduction, the 3B lens group G3B moves in a direction approximately perpendicular to the optical axis. Furthermore, when focusing from infinity to close distances, the 4B lens group G4B moves toward the image plane. Furthermore, the fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0097] The first lens group G1 is composed of a negative meniscus lens with its convex surface facing the object side, a biconvex lens, and a positive meniscus lens with its convex surface facing the object side, which are arranged in this order from the object side.

[0098] The second lens group G2 is composed of, arranged in order from the object side, a negative meniscus lens with its convex surface facing the object side, a biconcave lens, and a cemented lens consisting of a biconvex lens and a negative meniscus lens with its convex surface facing the image side.

[0099] The third lens group G3 is composed of the following lens groups arranged in sequence from the object side: 3A lens group G3A, which is composed of a double convex lens and a cemented lens composed of a double convex lens and a double concave lens; and 3B lens group G3B, which is composed of a cemented lens composed of a positive meniscus lens with the convex surface facing the image side and a double concave lens.

[0100] The 4th lens group G4 is composed of the following lens groups arranged in sequence from the object side: the 4A lens group G4A, which is composed of a double convex lens, a cemented lens composed of a double convex lens and a double concave lens, and a double convex lens; and the 4B lens group G4B, which is composed of a cemented lens composed of a positive meniscus lens with the convex surface facing the image side and a double concave lens.

[0101] The fifth lens group G5 is composed of a negative meniscus lens with its convex surface facing the object side and a biconvex lens, which are arranged in this order from the object side.

[0102] Furthermore, in the high-power zoom lens of Example 3, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Furthermore, the fifth lens group remains fixed relative to the image plane during zooming.

[0103] The following lists various specifications of the high-magnification zoom lens of Example 3. Numerical Example 3 Unit: mm [Surface data] [Aspherical surface data] [Various data] [Variable interval data] [Lens group data] [Example 4]

[0104] Figure 31 This is a lens configuration diagram of a high-magnification zoom lens according to Example 4 of the present invention.

[0105] Example 4 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, an aperture stop S, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and a fifth lens group G5 with positive refractive power. Furthermore, the third lens group G3 consists of, in order from the object side, the 3A lens group G3A with positive refractive power and the 3B lens group G3B with negative refractive power. Furthermore, the fourth lens group G4 consists of, in order from the object side, the 4A lens group G4A with positive refractive power and the 4B lens group G4B with negative refractive power. Furthermore, when correcting image blur during vibration reduction, the 3B lens group G3B moves in a direction approximately perpendicular to the optical axis. Furthermore, when focusing from infinity to close distances, the 4B lens group G4B moves toward the image plane. The fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0106] The first lens group G1 is composed of a negative meniscus lens with its convex surface facing the object side, a biconvex lens, and a positive meniscus lens with its convex surface facing the object side, which are arranged in this order from the object side.

[0107] The second lens group G2 is composed of, arranged in order from the object side, a negative meniscus lens with its convex surface facing the object side, a biconcave lens, and a cemented lens consisting of a biconvex lens and a negative meniscus lens with its convex surface facing the image side.

[0108] The third lens group G3 is composed of the following lens groups arranged in sequence from the object side: 3A lens group G3A, which is composed of a double convex lens and a cemented lens consisting of a double convex lens and a negative meniscus lens with the convex surface facing the image side; and 3B lens group G3B, which is composed of a cemented lens consisting of a positive meniscus lens with the convex surface facing the image side and a double concave lens.

[0109] The 4th lens group G4 is composed of the following lens groups arranged in sequence from the object side: the 4A lens group G4A, which is composed of a double convex lens, a double convex lens, and a cemented lens consisting of a negative meniscus lens with the convex surface facing the object side and a double convex lens; and the 4B lens group G4B, which is composed of a negative meniscus lens with the convex surface facing the object side.

[0110] The fifth lens group G5 is composed of a cemented lens composed of a biconvex lens and a negative meniscus lens with its convex surface facing the image side, which are arranged in this order from the object side.

[0111] Furthermore, in the high-power zoom lens of Example 4, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Furthermore, the fifth lens group G5 remains fixed relative to the image plane during zooming.

[0112] The following lists various specification values of the high-magnification zoom lens according to Example 4. Numerical Example 4 Unit: mm [Surface data] [Aspherical surface data] [Various data] [Variable interval data] [Lens group data] [Example 5]

[0113] Figure 41 This is a lens configuration diagram of a high-magnification zoom lens according to Example 5 of the present invention.

[0114] Example 5 consists of, in order from the object side, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, an aperture stop S, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, and a fifth lens group G5 with positive refractive power. Furthermore, the third lens group G3 consists of, in order from the object side, the 3A lens group G3A with positive refractive power and the 3B lens group G3B with negative refractive power. Furthermore, the fourth lens group G4 consists of, in order from the object side, the 4A lens group G4A with positive refractive power and the 4B lens group G4B with negative refractive power. When correcting image blur during vibration reduction, the 3B lens group G3B moves in a direction approximately perpendicular to the optical axis. Furthermore, when focusing from infinity to close distances, the 4B lens group G4B moves toward the image plane. The fifth lens group G5 corresponds to the Lth lens group GL, which is located closest to the image side.

[0115] The first lens group G1 consists of, arranged in order from the object side, a negative meniscus lens with its convex surface facing the object side, a positive meniscus lens with its convex surface facing the object side, and a positive meniscus lens with its convex surface facing the object side.

[0116] The second lens group G2 is composed of a negative meniscus lens with its convex surface facing the object side, a biconcave lens, and a cemented lens composed of a biconvex lens and a biconcave lens, which are arranged in this order from the object side.

[0117] The third lens group G3 is composed of the following lens groups arranged in sequence from the object side: 3A lens group G3A, which is composed of a double convex lens and a cemented lens composed of a double convex lens and a double concave lens; and 3B lens group G3B, which is composed of a cemented lens composed of a positive meniscus lens with the convex surface facing the image side and a double concave lens.

[0118] The 4th lens group G4 is composed of the following lens groups arranged in sequence from the object side: the 4A lens group G4A, which is composed of a double convex lens, a double convex lens, and a cemented lens consisting of a negative meniscus lens with the convex side facing the object side and a double convex lens; and the 4B lens group G4B, which is composed of a cemented lens consisting of a positive meniscus lens with the convex side facing the image side and a double concave lens.

[0119] The fifth lens group G5 is composed of a cemented lens composed of a positive meniscus lens with its convex surface facing the image side and a negative meniscus lens with its convex surface facing the image side, which are arranged in this order from the object side.

[0120] Furthermore, in the high-power zoom lens of Example 5, when zooming from the wide-angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Furthermore, the fifth lens group G5 remains fixed relative to the image plane during zooming.

[0121] The following lists various specifications of the high-magnification zoom lens according to Example 5. Numerical Example 5 Unit: mm [Surface data] [Aspherical surface data] [Various data] [Variable interval data] [Lens group data]

[0122] The following is a list of corresponding values of the conditional expressions in the above-mentioned embodiments. [Conditional value]

[0123] <Other implementation methods> The technology disclosed in this embodiment is not limited to the above-mentioned embodiments and examples, and various modifications are possible. The shapes and values of the various parts shown in the above-mentioned numerical examples are only examples for implementing this technology, and the technical scope of this technology should not be interpreted as being limited by these examples.

[0124] The present technology can adopt the following structures. [1] A high-magnification zoom lens, characterized in that: The lens has, arranged in order from the object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and an Lth lens group GL having positive refractive power and located closest to the image side. When zooming from the wide-angle end to the telephoto end, the distance between the lens groups changes. The third lens group G3 is composed of a 3A lens group G3A with positive refractive power and a 3B lens group G3B with negative refractive power. Image blur correction is performed by moving the 3B lens group G3B in a direction substantially perpendicular to the optical axis. The fourth lens group G4 is composed of a 4A lens group G4A with positive refractive power and a 4B lens group G4B with negative refractive power. By moving the 4B lens group G4B from the object side to the image side in the optical axis direction, focusing is performed from the infinite distance state to the close distance. The high-magnification zoom lens satisfies the following conditional expression. (1)0.25<f1 / fT<0.66 (2) 0.35<|ff / fr|<0.80 f1: focal length of the first lens group G1 fT: The focal length of the entire high-magnification zoom lens at infinity at the telephoto end ff: The combined focal length of the first lens group G1 and the second lens group G2 at infinity at the wide-angle end fr: The combined focal length from the third lens group G3 to the Lth lens group GL at infinity at the wide-angle end [2] According to the high-magnification zoom lens described in [1], another feature of the present invention is that: The distance between the 4A lens group G4A and the 4B lens group G4B in the infinite state is constant during zooming. [3] According to the high-magnification zoom lens described in [1] or [2], another feature of the present invention is that: The distance between the 3A lens group G3A and the 3B lens group G3B is constant during zooming. [4] The high-magnification zoom lens according to any one of [1] to [3] is further characterized in that: The 3B lens group G3B is a cemented lens consisting of a positive lens and a negative lens. [5] The high-magnification zoom lens according to any one of [1] to [4] is further characterized in that: The 4B lens group G4B is a negative lens or a cemented lens consisting of a positive lens and a negative lens. [6] The high-magnification zoom lens according to any one of [1] to [5] is further characterized in that: The Lth lens group GL located closest to the image side is fixed relative to the image plane. [7] According to any one of [1] to [6], another feature of the present invention is that: The first lens group G1 is composed of one negative lens and two positive lenses arranged in order from the object side. [8] According to any one of [1] to [7], another feature of the present invention is that: The 4A lens group G4A includes at least two positive lenses and one negative lens. [9] According to any one of [1] to [8], another feature of the present invention is that the high-magnification zoom lens satisfies the following conditional expression. (3)0.60<|f4B / f4|<1.80 f4B: focal length of the 4B lens group G4B f4: focal length of the fourth lens group G4

[10] According to any one of [1] to [9], another feature of the present invention is that the high-magnification zoom lens satisfies the following conditional expression. (4)0.08<FB / LT<0.20 FB: Back focus distance in air conversion at wide angle LT: Total optical length at wide angle

[11] According to any one of [1] to

[10] , another feature of the present invention is that: The following conditional expressions are satisfied. (5)0.50<f3 / f4<5.00 f3: focal length of the third lens group G3 f4: focal length of the fourth lens group G4

[12] The high-magnification zoom lens according to any one of [1] to

[11] , further characterized in that: The following conditional expressions are satisfied. (6)0.010<ΔPgF_3A<0.073 ΔPgF_3A: The maximum anomalous dispersion of the g-line and F-line anomalous dispersions of the positive lens included in the 3A lens group G3A

[13] According to any one of [1] to

[12] , another feature of the present invention is that: The following conditional expressions are satisfied. (7)0.010<ΔPgF_1<0.073 ΔPgF_1: The maximum anomalous dispersion of the g-line and F-line anomalous dispersion of the positive lens included in the first lens group G1 Explanation of symbols

[0125] G1-1st lens group, G2-2nd lens group, G3-3rd lens group, G4-4th lens group, G5-5th lens group, GL-Lth lens group, S-aperture stop, I-image plane.

Claims

1. A high-magnification zoom lens, characterized in that: The lens has, arranged in order from the object side, a first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having positive refractive power, and an Lth lens group (GL) having positive refractive power and located closest to the image side. When zooming from the wide-angle end to the telephoto end, the distance between the lens groups changes. The third lens group (G3) is composed of a 3A lens group (G3A) with positive refractive power and a 3B lens group (G3B) with negative refractive power. Image blur correction is performed by moving the 3B lens group (G3B) in a direction substantially perpendicular to the optical axis. The fourth lens group (G4) is composed of a 4A lens group (G4A) with positive refractive power and a 4B lens group (G4B) with negative refractive power. By moving the 4B lens group (G4B) from the object side to the image side in the optical axis direction, focusing is performed from the infinite distance state to the close distance. The high-magnification zoom lens satisfies the following conditional formula: (1)0.25<f1 / fT<0.66 (2) 0.35<|ff / fr|<0.80 f1 is the focal length of the first lens group (G1), fT is the focal length of the entire high-magnification zoom lens at infinity at the telephoto end. ff is the combined focal length of the first lens group (G1) and the second lens group (G2) in the infinite state at the wide-angle end, fr is the combined focal length from the third lens group (G3) to the Lth lens group (GL) in the infinity state at the wide-angle end.

2. The high-magnification zoom lens according to claim 1, wherein: The distance between the 4A lens group (G4A) and the 4B lens group (G4B) in the infinite state is constant during zooming.

3. The high-magnification zoom lens according to claim 1, wherein: The interval between the 3A lens group (G3A) and the 3B lens group (G3B) is constant during zooming.

4. The high-magnification zoom lens according to claim 1, wherein: The 3B lens group (G3B) is a cemented lens consisting of a positive lens and a negative lens.

5. The high-magnification zoom lens according to claim 1, wherein: The 4B lens group (G4B) is a negative lens or a cemented lens consisting of a positive lens and a negative lens.

6. The high-magnification zoom lens according to claim 1, wherein: The Lth lens group (GL) located closest to the image side is fixed relative to the image plane.

7. The high-magnification zoom lens according to claim 1, wherein: The first lens group (G1) consists of one negative lens and two positive lenses arranged in order from the object side.

8. The high-magnification zoom lens according to claim 1, wherein: The 4A lens group (G4A) includes at least two positive lenses and one negative lens.

9. The high-magnification zoom lens according to any one of claims 1 to 8, wherein: The following conditions are met: (3)0.60<|f4B / f4|<1.80 f4B is the focal length of the 4B lens group (G4B), f4 is the focal length of the fourth lens group (G4).

10. The high-magnification zoom lens according to any one of claims 1 to 8, wherein: The following conditions are met: (4)0.08<FB / LT<0.20 FB is the back focal length in air conversion at the wide-angle end. LT is the total optical length at the wide-angle end.

11. The high-magnification zoom lens according to any one of claims 1 to 8, wherein: The following conditions are met: (5)0.50<f3 / f4<5.00 f3 is the focal length of the third lens group (G3), f4 is the focal length of the fourth lens group (G4).

12. The high-magnification zoom lens according to any one of claims 1 to 8, wherein: The following conditions are met: (6)0.010<ΔPgF_3A<0.073 ΔPgF_3A is the largest anomalous dispersion among the anomalous dispersions of the positive lens included in the 3A lens group (G3A) at the g-line and the F-line.

13. The high-magnification zoom lens according to any one of claims 1 to 8, wherein: The following conditions are met: (7)0.010<ΔPgF_1<0.073 ΔPgF_1 is the maximum anomalous dispersion of the g-line and F-line anomalous dispersion of the positive lens included in the first lens group ( G1 ).

Images