A large aperture anamorphic lens

Abstract

This invention discloses a large-aperture anamorphic lens, comprising an anamorphic group composed of cylindrical lenses and an imaging group composed of spherical lenses arranged sequentially from the object side to the image side. The anamorphic group includes a first lens, a second lens, and a third lens arranged sequentially from the object side to the image side. The first and second lenses are negative-power cylindrical lenses, and the third lens is a positive-power cylindrical lens. Utilizing the optical characteristics of the cylindrical lenses constituting the anamorphic group, the incoming horizontal light rays are "compressed," while the light rays entering the vertical field of view remain unchanged. After further comprehensive correction by the subsequent imaging group, the horizontal field of view angle is increased by 33%, thereby achieving 1.33X anamorphic shooting. Furthermore, this solution results in a smaller, lighter, and relatively lower-cost lens, better meeting the needs of most ordinary users.

Description

Technical Field

[0001] The present invention relates to the technical field of lenses, and in particular to a 35mm focal length, half-frame, large aperture anamorphic lens. Background Art

[0002] With the rapid development of Internet technology, taking photos and videos have become an indispensable part of the lives of ordinary consumers. In recent years, with the promotion of technologies such as 5G, more and more videos such as Vlog are shared, and more and more people are using mobile phones, cameras and other tools to shoot short videos and micro-movies.

[0003] However, the conventional shooting ratio of mobile phones, tablets, cameras and other devices on the market is 16:9, while the ratio of wide-screen videos with a cinematic feel is 2.4:1. Therefore, users need to crop the captured images through manual editing or digital cropping. However, cropping will sacrifice the pixels of the image.

[0004] Some professional anamorphic movie lens brands, such as Hawk from Germany, Cooke from the United Kingdom, ARRI from Germany, Panavision from the United States, and Angenieux from France, are usually aimed at professional-level customers. The prices are generally tens of thousands of dollars or even more expensive, and the anamorphic lenses themselves weigh several kilograms.

[0005] Expensive and heavy professional anamorphic lenses are not suitable for ordinary users. Therefore, how to make large aperture anamorphic lenses smaller and lighter is a technical problem that needs to be solved. Summary of the invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the professional large aperture anamorphic lens in the prior art that it is heavy in weight and high in price and is not suitable for use by ordinary users, thereby providing a large aperture anamorphic lens.

[0007] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0008] A large aperture anamorphic lens, comprising an anamorphic group composed of cylindrical lenses and an imaging group composed of spherical lenses, which are arranged in sequence from the object side to the image side, wherein the anamorphic group comprises a first lens, a second lens and a third lens, which are arranged in sequence from the object side to the image side, wherein the first lens and the second lens are cylindrical lenses with negative optical power, and the third lens is a cylindrical lens with positive optical power; the imaging group comprises a fourth lens, ..., an N-th lens, which are arranged in sequence along an optical path pointing to the image side; wherein N is a natural number greater than or equal to 10;

[0009] The focal power distribution of the lenses constituting the deformation group and the lenses constituting the imaging group satisfies the following relationship:

[0010] 300 <abs(f 1-3 / f 4-N ) ;

[0011] 30mm <f 4-N <40mm;

[0012] 1.20 <f 4-N / f 1-N <1.50;

[0013] Where, f represents the focal length of the lens in the X direction, and the subscript number of f represents the number of the twelve lenses that constitute the anamorphic lens, that is, f 1 is the focal length of the first lens in the X direction, f 1-N It is the combined focal length in the X direction of the N lenses, i.e. the first lens to the Nth lens.

[0014] Furthermore, the imaging group sequentially arranges a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens along the direction of the optical path pointing to the image side.

[0015] Furthermore, the focal power distribution of the lenses constituting the deformation group and the lenses constituting the imaging group also satisfies the following relationship:

[0016] -1.40 <f 2-3 / f 1 <-1.25;

[0017] 1.50 <f 4-7 / f 4-12 <2.60;

[0018] 0.60 <f 8-12 / f 4-12 <0.80;

[0019] 0.90 <f 10-12 / f 8-12 <1.30;

[0020] Where, f represents the focal length of the lens in the X direction, and the subscript number of f represents the number of the twelve lenses that constitute the anamorphic lens, that is, f 1 is the focal length of the first lens in the X direction, f 1-12 It is the combined focal length in the X direction of the 12 lenses, i.e. the first lens to the 12th lens.

[0021] Further, the fourth lens, the seventh lens, the eighth lens and the twelfth lens are all spherical lenses with negative optical power, and the fifth lens, the sixth lens, the ninth lens, the tenth lens and the eleventh lens are all spherical lenses with positive optical power.

[0022] Furthermore, the second lens and the third lens are bonded together.

[0023] Furthermore, the sixth lens and the seventh lens are bonded together.

[0024] Furthermore, the eighth lens and the ninth lens are bonded together.

[0025] Furthermore, the eleventh lens and the twelfth lens are bonded together.

[0026] Furthermore, the length of the anamorphic lens is less than 115 mm, and the largest outer diameter of the anamorphic lens is less than 80 mm.

[0027] Furthermore, the focal length of the anamorphic lens in the Y direction is 35 mm, and the aperture is 1.8.

[0028] Furthermore, the mass of the anamorphic lens is less than 700g.

[0029] The technical solution of the present invention has the following advantages:

[0030] 1. The large aperture anamorphic lens provided by the present invention comprises an anamorphic group composed of cylindrical lenses and an imaging group composed of spherical lenses, which are arranged in sequence from the object side to the image side. The anamorphic group comprises a first lens, a second lens and a third lens, which are arranged in sequence from the object side to the image side. The first lens and the second lens are negative optical power cylindrical lenses, and the third lens is a positive optical power cylindrical lens.

[0031] By using the optical properties of the cylindrical lenses that make up the anamorphic group, the light entering horizontally is "compressed", while the light entering vertically remains unchanged. The light is then comprehensively corrected by the subsequent imaging group, thereby increasing the field of view of the lens shooting horizontally and making the width of the actual shot wider. There is no need for post-editing, and 2.4:1 widescreen videos or photos can be obtained without sacrificing pixels. At the same time, because the anamorphic group is composed of cylindrical lenses, the anamorphic lens of this solution will have optical characteristics such as elliptical out-of-focus spots and sci-fi line flares in addition to the anamorphic function.

[0032] 2. The large aperture anamorphic lens provided by the present invention has a focal length distribution of the lenses constituting the anamorphic group and the lenses constituting the imaging group that satisfies the following relationship: <abs(f 1-3 / f 4-12 );30mm <f 4-12 <40mm; 1.20 <f 4-12 / f 1-12 <1.50 ; -1.40 <f 2-3 / f 1 <-1.30 ; 1.50 <f4-7 / f 4-12 <2.60; 0.60 <f 8-12 / f 4-12 <0.80; 0.90 <f 10-12 / f 8-12 <1.30;

[0033] Where, f represents the focal length of the lens in the X direction, and the number after f represents the number of the twelve lenses that make up the anamorphic lens, that is, f 1 is the focal length of the first lens in the X direction, f 1-12 It is the combined focal length in the X direction of the 12 lenses, i.e. the first lens to the twelfth lens, and the rest are similar.

[0034] The horizontal shooting angle of the 35mmF1.8 half-frame lens is increased by 33% while the vertical angle remains unchanged, resulting in a small-volume, large-aperture 35mm anamorphic lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 This is an optical structure diagram in the X direction of the first embodiment of the present invention;

[0037] Figure 2 This is a Y-direction optical structure diagram of the first embodiment of the present invention;

[0038] Figure 3 This is an optical structure diagram in the X direction of the second embodiment of the present invention;

[0039] Figure 4 This is a Y-direction optical structure diagram of the second embodiment of the present invention;

[0040] Figure 5 This is an optical structure diagram in the X direction of the third embodiment of the present invention;

[0041] Figure 6 This is the optical structure diagram in the Y direction of the third embodiment of the present invention.

[0042] Description of reference numerals:

[0043] 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. Deformation group; 14. Imaging group. DETAILED DESCRIPTION

[0044] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0048] Embodiment 1

[0049] like Figure 1 and Figure 2 A 35mm focal length half-frame large aperture anamorphic lens is shown, which is composed of twelve lenses arranged along the optical path from the object side to the image side, namely a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, an eleventh lens 11 and a twelfth lens 12.

[0050] Among them, the first lens 1, the second lens 2, and the third lens 3 are cylindrical lenses, the second lens 2 and the third lens 3 are bonded together, and the three cylindrical lenses constitute a deformation group 13. The fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, the ninth lens 9, the tenth lens 10, the eleventh lens 11, and the twelfth lens 12 are nine spherical lenses that constitute an imaging group.

[0051] Among them, the first lens 1 is a negative power cylindrical lens, the second lens 2 is a negative cylindrical lens, and the third lens 3 is a positive power cylindrical lens.

[0052] Among them, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, the ninth lens 9, the tenth lens 10, the eleventh lens 11 and the twelfth lens 12 are spherical lenses. The fourth lens 4, the seventh lens 7, the eighth lens 8 and the twelfth lens 12 are all negative power spherical lenses, and the fifth lens 5, the sixth lens 6, the ninth lens 9, the tenth lens 10 and the eleventh lens 11 are all positive power spherical lenses. Among them, the sixth lens 6 and the seventh lens 7 are bonded together, the eighth lens 8 and the ninth lens 9 are bonded together, and the eleventh lens 11 and the twelfth lens 12 are bonded together.

[0053] The lenses bonded together are considered as a whole. In this embodiment, the second lens 2 and the third lens 3 are bonded together, the sixth lens 6 and the seventh lens 7 are bonded together, the eighth lens 8 and the ninth lens 9 are bonded together, and the eleventh lens 11 and the twelfth lens 12 are bonded together. Therefore, the anamorphic lens of this embodiment is composed of 12 lenses and 8 groups.

[0054] There is no specific restriction on the combination method between the second lens 2 and the third lens 3, the sixth lens 6 and the seventh lens 7, the eighth lens 8 and the ninth lens 9, and the eleventh lens 11 and the twelfth lens 12. In this embodiment, the combination method is bonding. As an alternative implementation method, based on the concept of the present invention, in order to distinguish from the present application, the above combination methods are changed, such as bonding, integrated molding, etc., and the shape of the combined lenses is adaptively changed, which should also be included in the protection scope of the present application.

[0055] There is no specific restriction on the specific values ​​of the actual parameters of each lens. In this embodiment, the focal length of each lens or lens group satisfies the following mathematical relationship:

[0056] 300 <abs(f 1-3 / f 4-12 ) ;

[0057] 30mm <f 4-12 <40mm;

[0058] 1.20 <f4-12 / f 1-12 <1.50;

[0059] -1.40 <f 2-3 / f 1 <-1.30;

[0060] 1.50 <f 4-7 / f 4-12 <2.60;

[0061] 0.60 <f 8-12 / f 4-12 <0.80;

[0062] 0.90 <f 10-12 / f 8-12 <1.30;

[0063] Where, f represents the focal length of the lens in the X direction, and the number after f represents the number of the twelve lenses that make up the anamorphic lens, that is, f 1 is the focal length of the first lens in the X direction, f 1-12 It is the combined focal length in the X direction of the 12 lenses, i.e. the first lens to the twelfth lens, and the rest are similar.

[0064] The actual parameters of each lens of this embodiment that conform to the above mathematical relationship are listed below:

[0065]

[0066] Among them, the first to third lenses are cylindrical lenses, and the fourth to twelfth lenses are spherical lenses.

[0067] Before the anamorphic lens of this embodiment is used, the field of view angle of the lens with a focal length of 35 mm and an aperture of 1.8 is: V (vertical) 25.42°, H (horizontal) 37.39°.

[0068] After adopting the anamorphic lens of this embodiment, the field of view angle of the lens with a focal length of 35 mm and an aperture of 1.8 is: V (vertical) 25.42°, H (horizontal) 49.85°.

[0069] The comparison test shows that the vertical field of view angle remains unchanged, and the horizontal field of view angle deformation ratio is: 49.85 / 37.39=1.333.

[0070] The actual width ratio is in the range of 2.35-2.40, so the distortion ratio is 1.33, which means that the horizontal field of view angle is increased by 33%, thus achieving 1.33X distortion shooting.

[0071] When the anamorphic lens of this embodiment is manufactured, the length of the anamorphic lens itself is less than 115 mm, the maximum outer diameter is less than 80 mm, and the weight is less than 700 g, which is much smaller than the photographic and video interchangeable lenses of the same specifications, and also much smaller than the professional film anamorphic lenses of the same specifications on the market.

[0072] There is no specific restriction on the material used to make each lens. In this embodiment, each lens is made of optical glass.

[0073] The lens of the present application can be designed to be compatible with the bayonet mounts of various brands of cameras on the market according to actual usage requirements, so as to achieve personalized customization and universal coordination.

[0074] Embodiment 2

[0075] like Figure 3 and Figure 4 As shown, this embodiment provides a 35mm focal length half-frame large aperture anamorphic lens, which is different from the first embodiment in that the cemented lens of the original eleventh lens 11 and the twelfth lens 12 is replaced by a positive spherical lens.

[0076] Embodiment 3

[0077] like Figure 5 and Figure 6 As shown, this embodiment provides a 35mm focal length half-frame large aperture anamorphic lens, which is different from the first embodiment in that the fourth lens 4 with the original negative optical power is replaced by a spherical lens with positive optical power.

[0078] Obviously, the above embodiments are only examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. Obvious variations are listed below:

[0079] In this embodiment, based on the first embodiment, the bonded sixth lens 6 and seventh lens 7 can be divided into two independent lenses.

[0080] In this embodiment, based on the second embodiment, the fourth lens 4 and the fifth lens 5 can be combined into one lens.

[0081] In this embodiment, based on the first embodiment, the eighth lens 8 and the ninth lens 9 bonded together can be divided into two independent lenses.

[0082] In this embodiment, on the basis of the first and second embodiments, the eleventh lens 11 and the twelfth lens 12 bonded together can be combined into one lens.

[0083] In this embodiment, based on the first and second embodiments, the fifth lens 5 and the eleventh lens 10 are simply split into two or more lenses. As long as the focal length of the lens group after the split is within the scope of the original solution, there is no substantial innovation.

[0084] It is not necessary and impossible to list all the embodiments here, and the obvious changes or modifications derived therefrom are still within the protection scope of the invention.

Claims

1. A large aperture anamorphic lens, characterized in that: The invention comprises a deformation group composed of cylindrical lenses and an imaging group composed of spherical lenses, which are arranged in sequence from the object side to the image side. The deformation group comprises a first lens (1), a second lens (2) and a third lens (3) which are arranged in sequence from the object side to the image side. The first lens (1) and the second lens (2) are cylindrical lenses with negative optical power, and the third lens (3) is a cylindrical lens with positive optical power. The imaging group comprises a fourth lens (4), a fifth lens (5), a sixth lens (6), a seventh lens (7), an eighth lens (8), a ninth lens (9), a tenth lens (10), an eleventh lens (11) and a twelfth lens (12) which are arranged in sequence along the direction of the optical path pointing to the image side. The fourth lens (4), the seventh lens (7), the eighth lens (8) and the twelfth lens (12) are all spherical lenses with negative optical power, and the fifth lens (5), the sixth lens (6), the ninth lens (9), the tenth lens (10) and the eleventh lens (11) are all spherical lenses with positive optical power. The focal power distribution of the lenses constituting the deformation group and the lenses constituting the imaging group satisfies the following relationship: 300<abs(f 1－3 / f 4－12 ); 30mm<f 4－12 <40mm; 1.20<f 4－12 / f 1－12 <1.50; -1.40<f 2－3 / f1<-1.25; 1.50<f 4－7 / f 4－12 <2.60; 0.60<f 8－12 / f 4－12 <0.80; 0.90<f 10－12 / f 8－12 <1.30; Where, f represents the focal length of the lens in the X direction. The subscript numbers of f represent the numbers of the twelve lenses that make up the anamorphic lens. That is, f1 is the focal length of the first lens (1) in the X direction, and f 1－3 f is the combined focal length of the first lens (1) to the third lens (3) in the X direction, 4－12 is the combined focal length in the X direction of the fourth lens (4) to the twelfth lens (12), a total of 9 lenses, f 1－12 is the combined focal length in the X direction of the 12 lenses, i.e., the first lens (1) to the 12th lens (12), 2－3 f is the combined focal length of the second lens (2) to the third lens (3) in the X direction; 4－7 f is the combined focal length in the X direction of the fourth lens (4) to the seventh lens (7) totaling four lenses; 8－12 f is the combined focal length in the X direction of the eight lens (8) to the twelfth lens (12), a total of five lenses; 10－12 It is the combined focal length in the X direction of the tenth lens (10) to the twelfth lens (12), a total of three lenses.

2. The large aperture anamorphic lens according to claim 1, characterized in that: The second lens (2) and the third lens (3) are bonded together.

3. The large aperture anamorphic lens according to any one of claims 1 to 2, characterized in that: The sixth lens (6) and the seventh lens (7) are bonded together.

4. The large aperture anamorphic lens according to any one of claims 1 to 2, characterized in that: The eighth lens (8) and the ninth lens (9) are bonded together.

5. The large aperture anamorphic lens according to any one of claims 1 to 2, characterized in that: The eleventh lens (11) and the twelfth lens (12) are cemented together.

6. The large aperture anamorphic lens according to any one of claims 1 to 2, characterized in that: The length of the anamorphic lens is less than 115 mm, and the maximum outer diameter of the anamorphic lens is less than 80 mm.

7. The large aperture anamorphic lens according to any one of claims 1 to 2, characterized in that: The focal length of the anamorphic lens in the Y direction is 35 mm, and the aperture is 1.

8.

8. The large aperture anamorphic lens according to any one of claims 1 to 2, characterized in that: The mass of the anamorphic lens is less than 700g.

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