An anamorphic lens

Abstract

The present invention discloses a deformable lens, belonging to the field of optical lenses, which includes 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 arranged in sequence from the object side to the image side; the focal lengths of all lens groups satisfy: 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. An integrated design is adopted to achieve optical performances such as a small lens volume, a large aperture, high resolution, low breathing, low distortion, and a 1.33X deformation ratio while achieving a small lens volume.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, and more specifically to an anamorphic lens. Background Technology

[0002] With the rapid development of internet technology, taking photos and videos has become an indispensable part of ordinary consumers' lives. In recent years, driven by technologies such as 5G, video sharing such as vlogs has increased significantly, and more and more people are using mobile phones, cameras, and other tools to shoot short videos and micro-films.

[0003] However, the standard shooting ratio for 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, good short films or videos require lenses of different focal lengths working together, especially medium to long telephoto anamorphic lenses for close-ups of people.

[0004] Existing anamorphic lenses suffer from technical problems such as high price, large size and weight, large breathing effect and inconsistent magnification, and there are currently 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 high price, large size and weight, large breathing effect and inconsistent magnification of existing anamorphic lenses, thereby providing an anamorphic lens.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] An anamorphic lens includes 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 arranged sequentially from the object side to the image side.

[0008] 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.

[0009] The combined optical focal length of all lens groups satisfies the following condition:

[0010] 1.2 <f(G1-G7)Y / f(G1-G7)X<1.8;

[0011] -7.7 <f(G2)X / f(G1-G2)X<-6.9;

[0012] -1.8 <f(G6)Y / f(G3-G7)Y<-1.0;

[0013] 0.6 <f(G7)Y / f(G3-G7)Y<1.4;

[0014] -4.6 <f(G1-G2)X / f(G3-G7)X<-3.8;

[0015] Wherein, 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 combined optical focal length along the Y direction from the first cylindrical lens group to the fifth lens group, f(G1-G7)

[0016] X is the combined optical focal length along the X direction for the first cylindrical lens group to the fifth lens group, f(G2)X is the combined optical focal length along the X direction for the first spherical lens group, f(G1-G2)X is the combined optical focal length along the X direction for the first cylindrical lens group to the first spherical lens group, f(G6)Y is the combined optical focal length along the Y direction for the second cylindrical lens group, f(G7)Y is the combined optical focal length along the Y direction for the fifth lens group, f(G3-G7)Y is the combined optical focal length along the Y direction for the second spherical lens group (G3) to the fifth lens group, and f(G3-G7)X is the combined optical focal length along the X direction for the second spherical lens group (G3) to the fifth lens group.

[0017] Furthermore, the first cylindrical lens group includes a first lens, a second lens, and a third lens arranged sequentially from the object side to the image side along the optical path; 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.

[0018] The first spherical lens group includes a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially from the object side to the image side along the optical path; 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.

[0019] The second spherical lens group includes an eighth lens, a ninth lens, and a tenth lens arranged sequentially from the object side to the image side along the optical path. 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.

[0020] The third spherical lens group includes an eleventh lens; the eleventh lens is a spherical lens with negative optical power;

[0021] The fourth spherical lens group includes a twelfth lens and a thirteenth lens arranged sequentially from the object side to the image side along the optical path; the twelfth lens is a spherical lens with positive optical power, and the thirteenth lens is a spherical lens with negative optical power.

[0022] The second cylindrical lens group includes a fourteenth lens; the fourteenth lens is a cylindrical lens with negative optical power;

[0023] The fifth lens group includes a fifteenth lens, a sixteenth lens, a seventeenth lens, and an eighteenth lens arranged sequentially from the object side to the image side along the optical path; 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.

[0024] Furthermore, the eleventh lens constitutes an inner focusing group.

[0025] Further, the second lens and the third lens are cemented together to form a cemented doublet cylindrical lens; and / or, the fourth lens and the fifth lens are cemented together to form a cemented doublet spherical lens; and / or, the eighth lens and the ninth lens are cemented together to form a cemented doublet spherical lens; and / or, the twelfth lens and the thirteenth lens are cemented together to form a cemented doublet spherical lens; and / or, the fifteenth lens and the sixteenth lens are cemented together to form a cemented doublet spherical lens.

[0026] Furthermore, the composite optical focal length of the anamorphic lens in the Y direction is 73mm.

[0027] Furthermore, the zoom ratio of the anamorphic lens is 1.33X, and the magnification remains constant at different object distances.

[0028] Furthermore, the total optical length of the anamorphic lens does not exceed 145mm.

[0029] Furthermore, the aperture value of the anamorphic lens does not exceed 2.

[0030] 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.

[0031] The technical solution of this invention has the following advantages: By combining cylindrical and spherical lens groups in the X direction, the optical power is rationally allocated, making the optical structure of the anamorphic lens more compact and smaller, and reducing costs. The spherical lens group comprehensively corrects the light, and the optical characteristics of the cylindrical lens group "compress" horizontally entering light while keeping vertically entering light unchanged, thereby increasing the field of view for horizontal shooting and ensuring performance in the X direction. The cylindrical and spherical lens groups in the Y direction then stabilize the performance in the other direction. In this way, full-frame and high magnification are achieved. Furthermore, the compact design of the integrated cylindrical and spherical lenses makes the lens small in size and light in weight, significantly reducing costs. The aspherical lens effectively corrects spherical aberration and astigmatism, improving lens resolution while reducing lens size and weight. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is an optical structure diagram of the anamorphic lens in the X direction when the object-image distance is infinitely far in an embodiment of the present invention;

[0034] Figure 2 This is an optical structure diagram of the anamorphic lens in the Y direction when the object-image distance is infinitely far in an embodiment of the present invention;

[0035] Figure 3 This is a diagram showing the spherical aberration, field curvature, and distortion of the anamorphic lens when the object-image distance is infinitely far in an embodiment of the present invention.

[0036] 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;

[0037] 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;

[0038] Figure 6 This is a diagram showing the spherical aberration, field curvature, and distortion of the anamorphic lens when the object-image distance is 0.6m in an embodiment of the present invention.

[0039] Explanation of reference numerals in the attached diagram: 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 Implementation

[0040] 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.

[0041] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the 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.

[0042] 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 arranged sequentially along the optical path from the object side to the image side.

[0043] 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.

[0044] The combined optical focal length of all lens groups satisfies the following condition:

[0045] 1.2 <f(G1-G7)Y / f(G1-G7)X<1.8;

[0046] -7.7 <f(G2)X / f(G1-G2)X<-6.9;

[0047] -1.8 <f(G6)Y / f(G3-G7)Y<-1.0;

[0048] 0.6 <f(G7)Y / f(G3-G7)Y<1.4;

[0049] -4.6 <f(G1-G2)X / f(G3-G7)X<-3.8;

[0050] Wherein, 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 combined 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 combined 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 combined optical focal length of the first spherical lens group G2 along the X direction, and f(G1-G2)X is the combined optical focal length of the first cylindrical lens group G1. The combined optical focal lengths along the X direction from G1 to the first spherical lens group G2, f(G6)Y is the combined optical focal length along the Y direction from the second cylindrical lens group G6, f(G7)Y is the combined optical focal length along the Y direction from the fifth lens group G7, f(G3-G7)Y is the combined optical focal length along the Y direction from the second spherical lens group G3 to the fifth lens group G7, and f(G3-G7)X is the combined optical focal length along the X direction from the second spherical lens group G3 to the fifth lens group G7.

[0051] This type of anamorphic lens uses a combination of cylindrical and spherical lens groups in the X-direction to rationally distribute optical power, making the optical structure of the anamorphic lens more compact and cost-effective. The spherical lens group comprehensively corrects light rays, while the optical characteristics of the cylindrical lens group "compress" horizontally entering light rays, while keeping vertically entering light rays unchanged, thereby increasing the field of view for horizontal shooting and ensuring performance in the X-direction. The cylindrical and spherical lens groups in the Y-direction then stabilize performance in the other direction. This allows the lens to achieve full-frame and high magnification. Furthermore, the compact design of the integrated cylindrical and spherical lenses makes the lens small in size and light in weight, significantly reducing cost. The aspherical lens effectively corrects spherical aberration and astigmatism, improving lens resolution while reducing size and weight.

[0052] In some embodiments of this example, the first cylindrical lens group G1 includes a first lens 1, a second lens 2, and a third lens 3 arranged sequentially from the object side to the image side along the optical path; 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.

[0053] The first spherical lens group G2 includes a fourth lens 4, a fifth lens 5, a sixth lens 6, and a seventh lens 7 arranged sequentially from the object side to the image side along the optical path; 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.

[0054] The second spherical lens group G3 includes an eighth lens 8, a ninth lens 9, and a tenth lens 10 arranged sequentially from the object side to the image side along the optical path. The eighth lens 8 is a spherical lens with negative optical power, the ninth lens 9 is a spherical lens with positive optical power, and the tenth lens 10 is a spherical lens with positive optical power.

[0055] The third spherical lens group G4 includes the eleventh lens 11; the eleventh lens 11 is a spherical lens with negative optical power.

[0056] The fourth spherical lens group G5 includes a twelfth lens 12 and a thirteenth lens 13 arranged sequentially from the object side to the image side along the optical path; 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.

[0057] The second cylindrical lens group G6 includes the fourteenth lens 14; the fourteenth lens 14 is a cylindrical lens with negative optical power.

[0058] The fifth lens group G7 includes a fifteenth lens 15, a sixteenth lens 16, a seventeenth lens 17, and an eighteenth lens 18 arranged sequentially from the object side to the image side along the optical path; 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.

[0059] The focal length allocation 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;

[0060] -7.7 <f(4-7)X / f(1-7)X<-6.9;

[0061] -1.8 <f(14)Y / f(8-18)Y<-1.0;

[0062] 0.6 <f(15-18)Y / f(8-18)Y<1.4;

[0063] -4.6 <f(1-7)X / f(8-18)X<-3.8;

[0064] Among them, the curvature direction of the first cylindrical lens group G1 is the X direction, and the Y direction is perpendicular to the X direction; f(m-n)Y is the comprehensive optical focal length of the m-th lens to the n-th lens along the Y direction, f(m-n)X is the comprehensive optical focal length of the m-th lens to the n-th 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:

[0065] f(1-18)Y / f(1-18)X = 1.33;

[0066] f(4-7)X / f(1-7)X = -7.41;

[0067] f(14)Y / f(8-18)Y = -1.46;

[0068] f(15-18)Y / f(8-18)Y = 0.89;

[0069] f(1-7)X / f(8-18)X = -4.26.

[0070] In some other embodiments 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 changed, as long as the comprehensive optical focal lengths of various lens groups in the anamorphic lens satisfy the above mathematical relationships.

[0071] In this embodiment, the comprehensive optical focal length of the anamorphic lens in the Y direction is 73 mm. The zoom ratio of the anamorphic lens is 1.33X, and the magnification at different object distances remains constant. The overall optical length of the anamorphic lens does not exceed 145 mm. The aperture F value of the anamorphic lens does not exceed 2.

[0072] In this embodiment, the eleventh lens 11 forms an internal focusing group. When adjusting, the overall length of the lens remains unchanged, and a floating internal focusing group is used to achieve focusing from 0.6 m to infinity of the object image distance, while overcoming the technical difficulties of large breathing effect and non-constant magnification of the 73 mm anamorphic lens.

[0073] In this embodiment, the second lens 2 and the third lens 3 are cemented to form a doublet cylindrical lens; and / or, the fourth lens 4 and the fifth lens 5 are cemented to form a doublet spherical lens; the eighth lens 8 and the ninth lens 9 are cemented to form a doublet spherical lens; the twelfth lens 12 and the thirteenth lens 13 are cemented to form a doublet spherical lens; the fifteenth lens 15 and the sixteenth lens 16 are cemented to form a doublet spherical lens, and the doublet spherical lens is used to correct the optical chromatic aberration of the anamorphic lens in the horizontal and vertical directions.

[0074] It should be noted that the above-mentioned multiple sets of cemented doublet spherical lenses are joined by adhesive bonding. As an alternative implementation, based on the concept of this invention, and to distinguish it from this application, modifications to the joining method, such as bonding or integral molding, and adaptive changes to the shape of the joined lenses, should also be included within the scope of protection of this 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, or two consecutive lenses with the same optical power can be merged into one lens. Such simple transformations to the optical structure of this patent, such as the optical power allocation of the transformed lens or lens group within the range of the mathematical expression of this patent, are all within the scope of protection of this application, provided they do not depart from the spirit and intent of this application.

[0075] 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.

[0076] See Figure 3 As shown, the spherical aberration diagram, field curvature diagram, and distortion diagram of the anamorphic lens are presented. It can be seen from the curves in the figure that the spherical aberration is basically less than ±0.5, ensuring the sharpness of the image center; the field curvature is basically less than ±0.5, ensuring the same sharpness in a large field of view; and the distortion is less than 10%, ensuring that the image has a small deformation.

[0077] Reference Figure 4 and Figure 5 By adjusting the internal focus group within the anamorphic lens, the overall length of the anamorphic lens remains unchanged, achieving an ultra-close object distance of 0.6m for a high-magnification anamorphic lens in a full-frame camera.

[0078] See Figure 6 As shown, the spherical aberration diagram, field curvature diagram, and distortion diagram of the anamorphic lens at close object distance are shown. From the curves in the figure, it can be seen that the spherical aberration is basically less than ±0.5, ensuring the sharpness of the image center; the field curvature is basically less than ±0.5, ensuring the same sharpness in the large field of view; and the distortion is less than 10%, ensuring that the image has a small deformation.

[0079] Table 1 below lists the actual parameters of each lens in this embodiment that conform to the above mathematical relationships:

[0080] Table 1:

[0081]

[0082] Table 2 below shows the aspherical coefficients of the eighteenth lens 18:

[0083] Table 2:

[0084]

[0085] The anamorphic lens provided by this invention adopts an integrated design, achieving excellent optical performance at a cost-effective price while maintaining a small lens size, including high resolution, low breathing, low distortion, full-frame capability, and 1.33X magnification. It can be designed to be compatible with various brands of cameras on the market according to actual usage needs, so as to achieve personalized customization and universal compatibility.

[0086] 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 anamorphic lens has seven lens groups with optical power. The anamorphic lens 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) arranged sequentially from the object side to the image side along the optical path. 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 combined 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 X; f(G1-G7)Y is the combined 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 combined 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 combined optical focal length of the first spherical lens group (G2) along the X direction, and f(G1-G2)X is the combined 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 along the X direction from G1 to the first spherical lens group (G2), f(G6)Y is the combined optical focal length along the Y direction from the second cylindrical lens group (G6), f(G7)Y is the combined optical focal length along the Y direction from the fifth lens group (G7), f(G3-G7)Y is the combined optical focal length along the Y direction from the second spherical lens group (G3) to the fifth lens group (G7), and f(G3-G7)X is the combined optical focal length along the X direction from the second spherical lens group (G3) to the fifth lens group (G7).

2. The anamorphic lens according to claim 1, characterized in that, The first cylindrical lens group (G1) includes a first lens (1), a second lens (2) and a third lens (3) arranged sequentially from the object side to the image side along the optical path; 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) includes a fourth lens (4), a fifth lens (5), a sixth lens (6), and a seventh lens (7) arranged sequentially from the object side to the image side along the optical path; 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) includes an eighth lens (8), a ninth lens (9) and a tenth lens (10) arranged sequentially from the object side to the image side along the optical path. The eighth lens (8) is a spherical lens with negative optical power, the ninth lens (9) is a spherical lens with positive optical power, and the tenth lens (10) is 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) includes a twelfth lens (12) and a thirteenth lens (13) arranged sequentially from the object side to the image side along the optical path; 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) includes a fifteenth lens (15), a sixteenth lens (16), a seventeenth lens (17), and an eighteenth lens (18) arranged sequentially from the object side to the image side along the optical path; 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, characterized in that, The eleventh lens (11) constitutes the inner focusing group.

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

5. The anamorphic lens according to claim 1, characterized in that, The anamorphic lens has a combined optical focal length of 73mm in the Y direction.

6. The anamorphic lens according to claim 1, characterized in that, The anamorphic lens has a zoom ratio of 1.33X, and the magnification remains constant at different object distances.

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

8. The anamorphic lens according to claim 1, characterized in that, The aperture value of the anamorphic lens does not exceed 2.

9. The anamorphic lens according to claim 1, characterized in that, 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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