Deformable lens

Abstract

The invention discloses a deformable lens, which belongs to the field of optical lenses and comprises a first cylindrical lens group, a first spherical lens group, a second spherical lens group, a third spherical lens group, a fourth spherical lens group, a second cylindrical lens group and a fifth lens group which are sequentially arranged from an object space to an image space. The focal lengths of all the lens groups meet the following conditions: 1.2 lt; f (G1-G7) Y / f (G1-G7) Xlt; 1.8); -7.7 lt,-7.7 lt; f (G2) X / f (G1-G2) Xlt; -6.9,-6.9; -1.8 lt,-1.8 lt; f (G6) Y / f (G3-G7) Ylt; -1.0, and-1.0; 0.6 lt; f (G7) Y / f (G3-G7) Ylt; 1.4, 4; -4.6 lt,-4.6 lt; f (G1-G2) X / f (G3-G7) Xlt; and 3.8. The integrated design is adopted, so that the lens is small in size, and meanwhile, the optical performance of large aperture, high resolution, low respiration, low distortion, 1.33 X deformation ratio and the like is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and in particular to a anamorphic lens. Background Art

[0002] With the rapid development of internet technology, taking photos and videos has become an essential part of everyday life for ordinary consumers. In recent years, driven by technologies like 5G, the sharing of videos like vlogs has become increasingly popular, and more and more people are using mobile phones, cameras, and other tools to shoot short videos and micro-films.

[0003] However, the typical shooting ratio on mobile phones, tablets, cameras, and other devices on the market is 16:9, while the ratio for cinematic widescreen videos is 2.4:1. Furthermore, shooting a good micro-film or video requires lenses of different focal lengths to work together, especially close-ups of characters, which require medium- to long-focus anamorphic lenses.

[0004] Existing anamorphic lenses have technical problems such as high price, large size and weight, large breathing effect and unstable magnification, and there are almost no autofocus full-frame anamorphic lenses on the market. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the technical problems of the prior art anamorphic lenses, such as high price, large volume and weight, large breathing effect, and unstable magnification, thereby providing an anamorphic lens.

[0006] In order to solve the above technical problems, the technical solutions of the present invention are as follows: A deformable lens comprises a first cylindrical lens group, a first spherical lens group, a second spherical lens group, a third spherical lens group, a fourth spherical lens group, a second cylindrical lens group, and a fifth lens group, which are arranged in sequence from the object side to the image side.

[0007] The first cylindrical lens group has negative optical power, the first spherical lens group has positive optical power, the second spherical lens group has positive optical power, the third spherical lens group has negative optical power, the fourth spherical lens group has positive optical power, the second cylindrical lens group has negative optical power, and the fifth lens group has positive optical power.

[0008] The comprehensive optical focal length of all lens groups satisfies the following condition: 1.2 <f(G1-G7)Y / f(G1-G7)X<1.8; -7.7 <f(G2)X / f(G1-G2)X<-6.9; -1.8 <f(G6)Y / f(G3-G7)Y<-1.0; 0.6 <f(G7)Y / f(G3-G7)Y<1.4; -4.6 <f(G1-G2)X / f(G3-G7)X<-3.8; The curvature direction of the first cylindrical lens group is the X direction, and the Y direction is the direction perpendicular to X; f(G1-G7)Y is the comprehensive optical focal length of the first cylindrical lens group to the fifth lens group along the Y direction, and f(G1-G7) X is the combined optical focal length of the first cylindrical lens group to the fifth lens group along the X direction, f(G2)X is the combined optical focal length of the first spherical lens group along the X direction, f(G1-G2)X is the combined optical focal length of the first cylindrical lens group to the first spherical lens group along the X direction, f(G6)Y is the combined optical focal length of the second cylindrical lens group along the Y direction, f(G7)Y is the combined optical focal length of the fifth lens group along the Y direction, f(G3-G7)Y is the combined optical focal length of the second spherical lens group (G3) to the fifth lens group along the Y direction, and f(G3-G7)X is the combined optical focal length of the second spherical lens group (G3) to the fifth lens group along the X direction.

[0009] Furthermore, the first cylindrical lens group includes a first lens, a second lens, and a third lens arranged in sequence along the optical path from the object side to the image side; the first lens is a cylindrical lens with negative optical power, the second lens is a cylindrical lens with negative optical power, and the third lens is a cylindrical lens with positive optical power; The first spherical lens group includes a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in sequence along the optical path from the object side to the image side; the fourth lens is a spherical lens with negative optical power, the fifth lens is a spherical lens with positive optical power, the sixth lens is a spherical lens with negative optical power, and the seventh lens is a spherical lens with positive optical power; The second spherical lens group includes an eighth lens, a ninth lens, and a tenth lens arranged in sequence along the optical path from the object side to the image side, the eighth lens is a spherical lens with negative optical power, the ninth lens is a spherical lens with positive optical power, and the tenth lens is a spherical lens with positive optical power; The third spherical lens group includes an eleventh lens; the eleventh lens is a spherical lens with negative optical power; The fourth spherical lens group includes a twelfth lens and a thirteenth lens arranged in sequence along the optical path from the object side to the image side; the twelfth lens is a spherical lens with positive optical power, and the thirteenth lens is a spherical lens with negative optical power; The second cylindrical lens group includes a fourteenth lens; the fourteenth lens is a cylindrical lens with negative optical power; The fifth lens group includes a fifteenth lens, a sixteenth lens, a seventeenth lens, and an eighteenth lens arranged in sequence along the optical path from the object side to the image side; the fifteenth lens is a spherical lens with positive optical power, the sixteenth lens is a spherical lens with negative optical power, the seventeenth lens is a spherical lens with positive optical power, and the eighteenth lens is an aspherical lens with negative optical power.

[0010] Furthermore, the eleventh lens constitutes an inner focusing group.

[0011] Further, the second lens and the third lens are cemented to form a double cemented cylindrical lens; and / or, the fourth lens and the fifth lens are cemented to form a double cemented spherical lens; and / or, the eighth lens and the ninth lens are cemented to form a double cemented spherical lens; and / or, the twelfth lens and the thirteenth lens are cemented to form a double cemented spherical lens; and / or, the fifteenth lens and the sixteenth lens are cemented to form a double cemented spherical lens.

[0012] Furthermore, the comprehensive optical focal length of the anamorphic lens in the Y direction is 73 mm.

[0013] Furthermore, the zoom ratio of the anamorphic lens is 1.33X, and the magnification ratio remains constant at different object distances.

[0014] Furthermore, the total optical length of the anamorphic lens does not exceed 145 mm.

[0015] Furthermore, the aperture value of the anamorphic lens does not exceed 2.

[0016] Furthermore, the lenses in the first cylindrical lens group, the first spherical lens group, the second spherical lens group, the third spherical lens group, the fourth spherical lens group, the second cylindrical lens group and the fifth lens group are all optical glass lenses.

[0017] The technical solution of the present invention has the following advantages: by combining an X-direction cylindrical lens group and a spherical lens group, the optical power is rationally distributed, making the optical structure of the anamorphic lens more compact and cost-effective. The spherical lens group comprehensively corrects the light, and then utilizes the optical properties of the cylindrical lens group to "compress" the horizontally entering light while keeping the vertically entering light unchanged, thereby increasing the lens's horizontal field of view and ensuring performance in the X direction. The Y-direction cylindrical lens group and spherical lens group then stabilize performance in the other direction. In this way, the full frame and high magnification of the lens are achieved. In addition, the compact design of the integrated cylindrical and spherical lenses makes the lens small and lightweight, greatly reducing cost. The aspherical lens can effectively correct the lens's spherical aberration and astigmatism, improving the lens's resolution while reducing its size and weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is an optical structure diagram of the anamorphic lens in the X direction when the object-image distance is infinite in an embodiment of the present invention; Figure 2 This is an optical structure diagram of the anamorphic lens in the Y direction when the object-image distance is infinite in an embodiment of the present invention; Figure 3 Graphs showing spherical aberration, field curvature, and distortion of an anamorphic lens when the object-image distance is infinite in an embodiment of the present invention; Figure 4 : This is an optical structure diagram of the anamorphic lens in the X direction when the object-image distance is 0.6m in an embodiment of the present invention; Figure 5 : This is an optical structure diagram of the anamorphic lens in the Y direction when the object-image distance is 0.6m in an embodiment of the present invention; Figure 6 Graphs showing spherical aberration, field curvature, and distortion of the anamorphic lens when the object-image distance is 0.6 m in an embodiment of the present invention.

[0020] Explanation of the reference numerals: G1, first cylindrical lens group; G2, first spherical lens group; G3, second spherical lens group; G4, third spherical lens group; G5, fourth spherical lens group; G6, second cylindrical lens group; G7, fifth lens group; 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, fifth lens; 6, sixth lens; 7, seventh lens; 8, eighth lens; 9, ninth lens; 10, tenth lens; 11, eleventh lens; 12, twelfth lens; 13, thirteenth lens; 14, fourteenth lens; 15, fifteenth lens; 16, sixteenth lens; 17, seventeenth lens; 18, eighteenth lens. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] like Figures 1-6 The anamorphic lens shown includes a first cylindrical lens group G1, a first spherical lens group G2, a second spherical lens group G3, a third spherical lens group G4, a fourth spherical lens group G5, a second cylindrical lens group G6, and a fifth lens group G7, which are arranged in sequence along the optical path from the object side to the image side.

[0024] Among them, the first cylindrical lens group G1 has negative optical power, the first spherical lens group G2 has positive optical power, the second spherical lens group G3 has positive optical power, the third spherical lens group G4 has negative optical power, the fourth spherical lens group G5 has positive optical power, the second cylindrical lens group G6 has negative optical power, and the fifth lens group G7 has positive optical power.

[0025] The comprehensive optical focal length of all lens groups satisfies the following condition: 1.2 <f(G1-G7)Y / f(G1-G7)X<1.8; -7.7 <f(G2)X / f(G1-G2)X<-6.9; -1.8 <f(G6)Y / f(G3-G7)Y<-1.0; 0.6 <f(G7)Y / f(G3-G7)Y<1.4; -4.6 <f(G1-G2)X / f(G3-G7)X<-3.8; Among them, the curvature direction of the first cylindrical lens group G1 is the X direction, and the Y direction is the direction perpendicular to X; f(G1-G7)Y is the comprehensive optical focal length of the first cylindrical lens group G1 to the fifth lens group G7 along the Y direction, f(G1-G7)X is the comprehensive optical focal length of the first cylindrical lens group G1 to the fifth lens group G7 along the X direction, f(G2)X is the comprehensive optical focal length of the first spherical lens group G2 along the X direction, and f(G1-G2)X is the comprehensive optical focal length of the first cylindrical lens group G1 to the fifth lens group G7 along the X direction. The combined optical focal length from G1 to the first spherical lens group G2 along the X direction, f(G6)Y is the combined optical focal length from the second cylindrical lens group G6 along the Y direction, f(G7)Y is the combined optical focal length from the fifth lens group G7 along the Y direction, f(G3-G7)Y is the combined optical focal length from the second spherical lens group G3 to the fifth lens group G7 along the Y direction, and f(G3-G7)X is the combined optical focal length from the second spherical lens group G3 to the fifth lens group G7 along the X direction.

[0026] This anamorphic lens combines an X-direction cylindrical lens group with a spherical lens group to rationally distribute optical power, making the anamorphic lens's optical structure more compact and cost-effective. The spherical lens group provides comprehensive correction for light, and then leverages the optical properties of the cylindrical lens group to "compress" horizontally entering light while maintaining vertical light. This increases the lens' horizontal field of view and ensures performance in the X direction. The Y-direction cylindrical and spherical lens groups stabilize performance in the other direction. This enables the lens's full frame and high magnification. Furthermore, the compact, integrated design of the cylindrical and spherical lenses results in a small, lightweight lens, significantly reducing cost. The aspherical lens effectively corrects spherical aberration and astigmatism, improving resolution while reducing size and weight.

[0027] In some implementations of this embodiment, the first cylindrical lens group G1 includes a first lens 1, a second lens 2, and a third lens 3, which are arranged in sequence along the optical path from the object side to the image side; the first lens 1 is a cylindrical lens with negative optical power, the second lens 2 is a cylindrical lens with negative optical power, and the third lens 3 is a cylindrical lens with positive optical power.

[0028] The first spherical lens group G2 includes a fourth lens 4, a fifth lens 5, a sixth lens 6 and a seventh lens 7, which are arranged in sequence along the optical path from the object side to the image side; the fourth lens 4 is a spherical lens with negative optical power, the fifth lens 5 is a spherical lens with positive optical power, the sixth lens 6 is a spherical lens with negative optical power, and the seventh lens 7 is a spherical lens with positive optical power.

[0029] The second spherical lens group G3 includes an eighth lens 8, a ninth lens 9, and a tenth lens 10 arranged in sequence from the object side to the image side along the optical path. The eighth lens 8 is a spherical lens with a negative optical power, the ninth lens 9 is a spherical lens with a positive optical power, and the tenth lens 10 is a spherical lens with a positive optical power.

[0030] The third spherical lens group G4 includes an eleventh lens 11; the eleventh lens 11 is a spherical lens with a negative optical power.

[0031] The fourth spherical lens group G5 includes a twelfth lens 12 and a thirteenth lens 13 arranged in sequence from the object side to the image side along the optical path; the twelfth lens 12 is a spherical lens with a positive optical power, and the thirteenth lens 13 is a spherical lens with a negative optical power.

[0032] The second cylindrical lens group G6 includes a fourteenth lens 14; the fourteenth lens 14 is a cylindrical lens with a negative optical power.

[0033] The fifth lens group G7 includes a fifteenth lens 15, a sixteenth lens 16, a seventeenth lens 17, and an eighteenth lens 18 arranged in sequence from the object side to the image side along the optical path; the fifteenth lens 15 is a spherical lens with a positive optical power, the sixteenth lens 16 is a spherical lens with a negative optical power, the seventeenth lens 17 is a spherical lens with a positive optical power, and the eighteenth lens 18 is an aspherical lens with a negative optical power.

[0034] The focal length distribution of the first lens 1 to the eighteenth lens 18 satisfies the following relationship: 1.2 < f(1 - 18)Y / f(1 - 18)X < 1.8; -7.7 < f(4 - 7)X / f(1 - 7)X < -6.9; -1.8 < f(14)Y / f(8 - 18)Y < -1.0; 0.6 < f(15 - 18)Y / f(8 - 18)Y < 1.4; -4.6 < f(1 - 7)X / f(8 - 18)X < -3.8; Among them, the curvature direction of the first cylindrical lens group G1 is the X direction, and the Y direction is the direction perpendicular to X; f(m - n)Y is the combined optical focal length of the mth lens to the nth lens along the Y direction, f(m - n)X is the combined optical focal length of the mth lens to the nth lens along the X direction, m and n are both positive integers, and 1 ≤ m < n ≤ 18. In some embodiments of this embodiment, the focal length distribution of the first lens 1 to the eighteenth lens 18 satisfies the following conditions: f(1 - 18)Y / f(1 - 18)X = 1.33; f(4 - 7)X / f(1 - 7)X = -7.41; f(14)Y / f(8 - 18)Y = -1.46; f(15-18)Y / f(8-18)Y=0.89; f(1-7)X / f(8-18)X=-4.26.

[0035] In other implementations of this embodiment, the number of lenses in the anamorphic lens is not limited to 18 lenses, and the number of lenses in the anamorphic lens can be further varied as long as the combined optical focal lengths of the various lens groups in the anamorphic lens satisfy the above mathematical relationship.

[0036] In this embodiment, the anamorphic lens has a comprehensive optical focal length in the Y direction of 73 mm. The anamorphic lens has a zoom ratio of 1.33X, and the magnification ratio remains constant at different object distances. The total optical length of the anamorphic lens does not exceed 145 mm. The aperture value of the anamorphic lens does not exceed 2.

[0037] In this embodiment, the eleventh lens 11 forms an inner focusing group. The overall length of the lens remains unchanged during adjustment, and a floating inner focusing group is used to achieve focus from an object-image distance of 0.6m to infinity, while overcoming the technical difficulties of the large breathing effect and variable magnification of the 73mm anamorphic lens.

[0038] In this embodiment, the second lens 2 and the third lens 3 are cemented to form a double cemented cylindrical lens; and / or, the fourth lens 4 and the fifth lens 5 are cemented to form a double cemented spherical lens; the eighth lens 8 and the ninth lens 9 are cemented to form a double cemented spherical lens; the twelfth lens 12 and the thirteenth lens 13 are cemented to form a double cemented spherical lens; and the fifteenth lens 15 and the sixteenth lens 16 are cemented to form a double cemented spherical lens. The double cemented spherical lens is used to correct optical chromatic aberration of the anamorphic lens in the horizontal and vertical directions.

[0039] It should be pointed out that the above-mentioned multiple groups of double-glued spherical lenses are combined by bonding. As an alternative embodiment, based on the concept of the present invention, in order to distinguish it from the present application, after the above-mentioned combination method is changed, such as bonding, integral molding and other combination methods, and then the shape of the combined lens is adaptively changed, it should also be included in the protection scope of the present application. For a single lens or two consecutive lenses with the same optical power, a single lens can be split into two or more lenses, and two consecutive lenses with the same sign can be combined into one lens. Such simple transformations of the optical structure of the patent, such as the distribution of the optical power of the transformed lens or lens group, are within the scope of the mathematical relationship expression of the patent. On the basis of this embodiment, changes and replacements of the number and combination of lenses in order to distinguish it from the present application, without departing from the main idea of ​​the present application, all fall within the protection scope of the present application.

[0040] In this embodiment, the lenses in the first cylindrical lens group G1 , the first spherical lens group G2 , the second spherical lens group G3 , the third spherical lens group G4 , the fourth spherical lens group G5 , the second cylindrical lens group G6 and the fifth lens group G7 are all optical glass lenses.

[0041] See also Figure 3 As shown in the figure, the spherical aberration, field curvature and distortion diagrams of the anamorphic lens are as follows. It can be seen from the curves in the figure that the spherical aberration is basically less than ±0.5, ensuring the clarity of the image center; the field curvature is basically less than ±0.5, ensuring that the image has the same clarity in a large field of view; the distortion is less than 10%, ensuring that the imaging image has a small deformation.

[0042] Reference Figure 4 and Figure 5 By adjusting the internal focus group in the anamorphic lens, the overall length of the anamorphic lens remains unchanged, achieving an ultra-close object-to-image distance of 0.6m for a medium to large magnification anamorphic lens in full-frame.

[0043] See also Figure 6 As shown in the figure, the spherical aberration, field curvature and distortion diagrams of the anamorphic lens at close object distance are as follows. It can be seen from the curves in the figure that the spherical aberration is basically less than ±0.5, ensuring the clarity of the image center; the field curvature is basically less than ±0.5, ensuring the same clarity of the large field of view; the distortion is less than 10%, ensuring that the imaging screen has a small deformation.

[0044] Table 1 below lists the actual parameters of each lens of this embodiment that conform to the above mathematical relationship: Table 1:

[0045] Table 2 below shows the aspheric coefficients of the eighteenth lens 18: Table 2:

[0046] The anamorphic lens provided by this invention adopts an integrated design, achieving a compact lens size while also achieving excellent cost-effective optical performance such as high resolution, low breathing, low distortion, full frame, and a high magnification of 1.33X. It can be designed to be compatible with the mounts of various camera brands on the market according to actual usage requirements, enabling personalized customization and universal compatibility.

[0047] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An anamorphic lens, characterized in that: The lens comprises a first cylindrical lens group (G1), a first spherical lens group (G2), a second spherical lens group (G3), a third spherical lens group (G4), a fourth spherical lens group (G5), a second cylindrical lens group (G6), and a fifth lens group (G7), which are sequentially arranged along the optical path from the object side to the image side. The first cylindrical lens group (G1) has negative optical power, the first spherical lens group (G2) has positive optical power, the second spherical lens group (G3) has positive optical power, the third spherical lens group (G4) has negative optical power, the fourth spherical lens group (G5) has positive optical power, the second cylindrical lens group (G6) has negative optical power, and the fifth lens group (G7) has positive optical power; The comprehensive optical focal length of all lens groups satisfies the following condition: 1.2 <f(G1-G7)Y / f(G1-G7)X<1.8; -7.7 <f(G2)X / f(G1-G2)X<-6.9; -1.8 <f(G6)Y / f(G3-G7)Y<-1.0; 0.6 <f(G7)Y / f(G3-G7)Y<1.4; -4.6 <f(G1-G2)X / f(G3-G7)X<-3.8; Wherein, the curvature direction of the first cylindrical lens group (G1) is the X direction, and the Y direction is the direction perpendicular to the X direction; f(G1-G7)Y is the comprehensive optical focal length of the first cylindrical lens group (G1) to the fifth lens group (G7) along the Y direction, f(G1-G7)X is the comprehensive optical focal length of the first cylindrical lens group (G1) to the fifth lens group (G7) along the X direction, f(G2)X is the comprehensive optical focal length of the first spherical lens group (G2) along the X direction, f(G1-G2)X is the comprehensive optical focal length of the first cylindrical lens group (G1) to the first spherical lens group (G2) along the X direction, and f(G6) Y is the comprehensive optical focal length of the second cylindrical lens group (G6) along the Y direction, f(G7)Y is the comprehensive optical focal length of the fifth lens group (G7) along the Y direction, f(G3-G7)Y is the comprehensive optical focal length of the second spherical lens group (G3) to the fifth lens group (G7) along the Y direction, and f(G3-G7)X is the comprehensive optical focal length of the second spherical lens group (G3) to the fifth lens group (G7) along the X direction.

2. The anamorphic lens according to claim 1, wherein: The first cylindrical lens group (G1) comprises a first lens (1), a second lens (2) and a third lens (3) arranged in sequence along the optical path from the object side to the image side; the first lens (1) is a cylindrical lens with negative optical power, the second lens (2) is a cylindrical lens with negative optical power, and the third lens (3) is a cylindrical lens with positive optical power; The first spherical lens group (G2) comprises a fourth lens (4), a fifth lens (5), a sixth lens (6) and a seventh lens (7) arranged in sequence along the optical path from the object side to the image side; the fourth lens (4) is a spherical lens with negative optical power, the fifth lens (5) is a spherical lens with positive optical power, the sixth lens (6) is a spherical lens with negative optical power, and the seventh lens (7) is a spherical lens with positive optical power; The second spherical lens group (G3) comprises an eighth lens (8), a ninth lens (9) and a tenth lens (10) arranged in sequence along the optical path from the object side to the image side, the eighth lens (8) being a spherical lens with negative optical power, the ninth lens (9) being a spherical lens with positive optical power, and the tenth lens (10) being a spherical lens with positive optical power; The third spherical lens group (G4) includes an eleventh lens (11); the eleventh lens (11) is a spherical lens with negative optical power; The fourth spherical lens group (G5) comprises a twelfth lens (12) and a thirteenth lens (13) arranged in sequence along the optical path from the object side to the image side; the twelfth lens (12) is a spherical lens with positive optical power, and the thirteenth lens (13) is a spherical lens with negative optical power; The second cylindrical lens group (G6) includes a fourteenth lens (14); the fourteenth lens (14) is a cylindrical lens with negative optical power; The fifth lens group (G7) comprises a fifteenth lens (15), a sixteenth lens (16), a seventeenth lens (17), and an eighteenth lens (18) arranged in sequence along the optical path from the object side to the image side; the fifteenth lens (15) is a spherical lens with positive optical power, the sixteenth lens (16) is a spherical lens with negative optical power, the seventeenth lens (17) is a spherical lens with positive optical power, and the eighteenth lens (18) is an aspherical lens with negative optical power.

3. The anamorphic lens according to claim 2, wherein: The eleventh lens (11) constitutes an inner focusing group.

4. The anamorphic lens according to claim 2, wherein: The second lens (2) and the third lens (3) are glued together to form a double-cemented cylindrical lens; and / or, the fourth lens (4) and the fifth lens (5) are glued together to form a double-cemented spherical lens; and / or, the eighth lens (8) and the ninth lens (9) are glued together to form a double-cemented spherical lens; and / or, the twelfth lens (12) and the thirteenth lens (13) are glued together to form a double-cemented spherical lens; and / or, the fifteenth lens (15) and the sixteenth lens (16) are glued together to form a double-cemented spherical lens.

5. The anamorphic lens according to claim 1, wherein: The comprehensive optical focal length of the anamorphic lens in the Y direction is 73 mm.

6. The anamorphic lens according to claim 1, wherein: The zoom ratio of the anamorphic lens is 1.33X, and the magnification remains constant at different object distances.

7. The anamorphic lens according to claim 1, wherein: The total optical length of the anamorphic lens does not exceed 145 mm.

8. The anamorphic lens according to claim 1, wherein: The aperture value of the anamorphic lens does not exceed 2.

9. The anamorphic lens according to claim 1, wherein: The lenses in the first cylindrical lens group (G1), the first spherical lens group (G2), the second spherical lens group (G3), the third spherical lens group (G4), the fourth spherical lens group (G5), the second cylindrical lens group (G6) and the fifth lens group (G7) are all optical glass lenses.

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