A deformable lens

Abstract

The present invention discloses a anamorphic lens, comprising a cylindrical lens and a spherical lens arranged in sequence from the object side to the image side. A first lens, a second lens and a third lens are arranged in sequence from the object side to the image side, wherein the first lens and the second lens are negative optical power cylindrical lenses, and the third lens is a positive optical power cylindrical lens. By utilizing the optical properties of the cylindrical lens, the incoming horizontal light is "compressed", while the light entering the vertical field of view remains unchanged, and then after comprehensive aberration correction of the light, the horizontal field of view angle is increased by 33%, thereby achieving 1.33X anamorphic shooting. At the same time, since the lens of this solution is smaller in size, lighter in weight, and relatively lower in cost, it can better meet the usage needs of most ordinary users.

Description

Technical Field

[0001] The present invention relates to the technical field of lenses, and in particular to a 75mm 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. At the same time, good micro-film or video shooting requires lenses of different focal lengths to cooperate with each other, especially close-ups of characters require medium-to-long focal length anamorphic lenses.

[0004] In this regard, there are some professional anamorphic movie lens brands such as: Germany-Hawk, Britain-Cooke, Germany-ARRI, United States-Panavison, France-Angenieux and Hong Kong, China SLR. However, the above-mentioned anamorphic lenses are usually aimed at professional customers. Not only are they expensive, but they are also difficult to carry at all times due to their size and weight.

[0005] Expensive and heavy professional anamorphic lenses are not suitable for ordinary users. Therefore, how to reduce the size and weight of medium-long focal length and large aperture anamorphic lenses, which are very important in video shooting, 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 medium-long focal length and large aperture anamorphic lens in the prior art that the lens is heavy in weight and expensive and is not suitable for ordinary users, thereby providing an anamorphic lens.

[0007] In order to solve the above technical problems, the present invention provides an anamorphic lens, comprising a cylindrical lens group and a spherical lens group arranged in sequence from the object side to the image side, wherein the cylindrical lens group is a first lens, a second lens and a third lens in sequence, the first lens and the second lens are negative power cylindrical lenses, and the third lens is a positive power cylindrical lens;

[0008] The spherical lens group is provided with a fourth lens, ..., a thirteenth lens in sequence along the direction of the optical path pointing to the image side;

[0009] The first lens is a front fixed group of the anamorphic lens, the second lens, the third lens, ..., the eleventh lens are an inner focusing group of the anamorphic lens, and the twelfth lens and the thirteenth lens are a rear fixed group of the anamorphic lens; wherein the optical power distribution of the inner focusing group, the front fixed group and the rear fixed group is as follows:

[0010] 70mm<f(1-13)Y<80mm;

[0011] 50mm<f(1-13)X<62mm;

[0012] 1.20<f(1-13)Y / f(1-13)X<1.40;

[0013] -1.45<f1X / (f1-13)X<-1.20;

[0014] 0.90<f(2-11)X / f(1-13)X<1.10;

[0015] -1.10<f(12-13)X / f(1-13)X<-0.90;

[0016] Wherein, the curvature direction of the first lens is the X direction, the Y direction is the direction perpendicular to the X direction, f(1-13)Y represents the comprehensive optical focal length of the first lens to the thirteenth lens along the Y direction, f(1-13)X represents the comprehensive optical focal length of the first lens to the thirteenth lens along the X direction, f1X represents the comprehensive optical focal length of the first lens along the X direction, f(2-11)X represents the comprehensive optical focal length of the second lens to the eleventh lens along the X direction, and f(12-13)X represents the comprehensive optical focal length of the twelfth lens to the thirteenth lens along the X direction;

[0017] The sixth lens, the seventh lens, the ninth lens and the thirteenth lens are spherical lenses with negative optical power, and the fourth lens, the fifth lens, the eighth lens, the tenth lens, the eleventh lens and the twelfth lens are spherical lenses with positive optical power.

[0018] Furthermore, the second lens and the third lens are bonded together.

[0019] Furthermore, the fifth lens and the sixth lens are bonded together.

[0020] Furthermore, the seventh lens and the eighth lens are bonded together.

[0021] Furthermore, the length of the anamorphic lens is less than 120 mm.

[0022] Furthermore, the front end of the anamorphic lens matches a filter with a diameter of 67 mm.

[0023] Furthermore, the focal length of the anamorphic lens along the Y direction is 75 mm, the focal length along the X direction is 56.4 mm, and the aperture is 1.8.

[0024] Furthermore, the mass of the anamorphic lens is less than 700g.

[0025] The technical solution of the present invention has the following advantages:

[0026] 1. The anamorphic lens provided by the present invention uses an overall design method to distribute the optical power of three cylindrical lenses and at least seven spherical lenses to correct the overall aberration, thereby increasing the field angle of the lens for horizontal shooting and increasing the width of the actual shot picture. Since there is no need for post-editing, wide-screen videos or photos can be obtained without sacrificing pixels.

[0027] 2. In the anamorphic lens provided by the present invention, the anamorphic lens is configured to have a front fixed group, an inner focusing group and a rear fixed group, and an inner focusing design is adopted. The inner focusing group moves inside the lens, thereby enabling the lens to focus on different object distances.

[0028] 3. The anamorphic lens provided by the present invention adopts a compact design that integrates cylindrical and spherical surfaces, achieving a large aperture of 1.8 while being lightweight, wherein the lens length is less than 120 mm, the front end of the lens matches a filter with an outer diameter of 67 mm, and the lens mass is less than 700 g. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] Figure 1 This is an optical structure diagram of the anamorphic lens in the X direction in the first embodiment of the present invention;

[0031] Figure 2 This is an optical structure diagram of the anamorphic lens in the Y direction in the first embodiment of the present invention;

[0032] Figure 3 is an optical structure diagram of the anamorphic lens in the X direction in the second embodiment of the present invention;

[0033] Figure 4 FIG. 1 is an optical structure diagram of the anamorphic lens in the Y direction in the second embodiment of the present invention.

[0034] Description of reference numerals:

[0035] 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. Front fixed group; 15. Inner focusing group; 16. Rear fixed group. DETAILED DESCRIPTION

[0036] 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 them. 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] Embodiment 1

[0041] like Figure 1 and Figure 2As shown, the anamorphic lens given in this embodiment is specifically a 75mm focal length half-frame medium-telephoto large aperture anamorphic lens, which is composed of thirteen 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, a twelfth lens 12 and a thirteenth lens 13.

[0042] Among them, the first lens 1, the second lens 2, and the third lens 3 are cylindrical lenses, and the second lens 2 and the third lens 3 are bonded together. 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, the twelfth lens 12, and the thirteenth lens 13 are all spherical lenses.

[0043] Specifically, in this embodiment, the first lens 1 is a negative power cylindrical lens, the second lens 2 is a negative power cylindrical lens, and the third lens 3 is a positive power cylindrical lens. The sixth lens 6, the seventh lens 7, the ninth lens 9, and the thirteenth lens 13 are all negative power spherical lenses, and the fourth lens 4, the fifth lens 5, the eighth lens 8, the tenth lens 10, the eleventh lens 11, and the twelfth lens 12 are all positive power spherical lenses. The fifth lens 5 and the sixth lens 6 are bonded together, the seventh lens 7 and the eighth lens 8 are bonded together, and the ninth lens 9 and the tenth lens 10 are bonded together.

[0044] The lenses bonded together are regarded as a whole, therefore, the anamorphic lens of this embodiment is composed of 13 lenses in 9 groups. There is no specific restriction on the bonding method between the second lens 2 and the third lens 3, the fifth lens 5 and the sixth lens 6, the seventh lens 7 and the eighth lens 8, the ninth lens 9 and the tenth lens 10. In this embodiment, the bonding 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-mentioned bonding method is changed, such as bonding, integral molding and other bonding methods, and the shape of the combined lens is adaptively changed, which should also be included in the protection scope of the present application.

[0045] 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:

[0046] 70mm<f(1-12)Y<80mm;

[0047] 50mm<f(1-12)X<62mm;

[0048] 1.20<f(1-12)Y / f(1-12)X<1.40;

[0049] -1.45<f1X / (f1-13)X<-1.20;

[0050] 0.90<f(2-11)X / f(1-13)X<1.10;

[0051] -1.10<f(12-13)X / f(1-13)X<-0.90;

[0052] Wherein, the curvature direction of the first lens is the X direction, and the Y direction is the direction perpendicular to the X direction and is 90 degrees to the X direction. f(1-12)Y represents the comprehensive optical focal length of the 1st to 12th lenses of the lens in the Y direction, and f(1-12)X represents the comprehensive optical focal length of the 1st to 12th lenses of the lens in the X direction. f(1-13)X represents the comprehensive optical focal length of the first to thirteenth lenses along the X direction, f1X represents the comprehensive optical focal length of the first lens along the X direction, f(2-11)X represents the comprehensive optical focal length of the second to eleventh lenses along the X direction, and f(12-13)X represents the comprehensive optical focal length of the twelfth to thirteenth lenses along the X direction.

[0053] Furthermore, by adopting the above-mentioned anamorphic lens, while achieving a focal length of 75mm, an overall design method is used to distribute the optical power of three cylindrical lenses and at least seven spherical lenses to correct the overall aberration, thereby increasing the field of view of the lens for horizontal shooting and making the actual shooting picture width larger. Since there is no need for post-editing, wide-screen video or photos can be obtained without sacrificing pixels.

[0054] The actual parameters of each lens of this embodiment that conform to the above mathematical relationship are listed below:

[0055]

[0056]

[0057] Among them, the first to third lenses are cylindrical lenses, and the fourth to thirteenth lenses are spherical lenses.

[0058] Before the anamorphic lens of this embodiment is used, the field of view angle of the lens with a focal length of 75 mm and an aperture of 1.8 is: V (vertical) 12.16°, H (horizontal) 18.46°.

[0059] After adopting the anamorphic lens of this embodiment, the field of view angle of the lens with a focal length of 75 mm and an aperture of 1.8 is: V (vertical) 12.16°, H (horizontal) 24.70°.

[0060] The comparison test shows that the vertical field of view angle remains unchanged, and the horizontal field of view angle deformation ratio is: 24.70 / 18.46=1.338.

[0061] 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.

[0062] It can be seen from the above table that when the anamorphic lens of this embodiment is manufactured, the length of the anamorphic lens itself can be less than 120 mm, matching the universal specification filter with an outer diameter of 67 mm, and the weight is less than 700 g, which is much smaller than the professional movie anamorphic lens of the same specification on the market, greatly reducing the size of the anamorphic lens.

[0063] There is no specific restriction on the material used to make each lens. In this embodiment, each lens is made of optical glass.

[0064] 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.

[0065] Embodiment 2

[0066] like Figure 3 and Figure 4 As shown, this embodiment provides a 75mm focal length half-frame anamorphic lens. The difference from the first embodiment is that the cemented lens of the original fifth lens 5 and the sixth lens 6 is replaced by a positive spherical lens and a negative spherical lens. The technical effect of the present application can also be achieved, which will not be repeated here.

[0067] This embodiment is based on the first and second embodiments. If only a single positive lens or a negative lens is simply split, as long as the focal length distribution of the lens group after the split is within the scope of the original solution, it is considered to be no substantial innovation.

[0068] 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 deformable lens, characterized in that: It comprises a cylindrical lens group and a spherical lens group arranged in sequence from the object side to the image side, wherein the cylindrical lens group is a first lens, a second lens and a third lens in sequence, the first lens and the second lens are negative power cylindrical lenses, and the third lens is a positive power cylindrical lens; the spherical lens group is arranged in sequence along the direction of the optical path pointing to the image side, a fourth lens, ..., a thirteenth lens; The first lens is a front fixed group of the anamorphic lens, the second lens, the third lens, ..., the eleventh lens are an inner focusing group of the anamorphic lens, and the twelfth lens and the thirteenth lens are a rear fixed group of the anamorphic lens; wherein the optical power distribution of the inner focusing group, the front fixed group and the rear fixed group is as follows: 70mm<f(1-13)Y<80mm; 50mm<f(1-13)X<62mm; 1.20<f(1-13)Y / f(1-13)X<1.40; -1.45<f1X / (f1-13)X<-1.20; 0.90<f(2-11)X / f(1-13)X<1.10; -1.10<f(12-13)X / f(1-13)X<-0.90; Wherein, the curvature direction of the first lens is the X direction, the Y direction is the direction perpendicular to the X direction, f(1-13)Y represents the comprehensive optical focal length of the first lens to the thirteenth lens along the Y direction, f(1-13)X represents the comprehensive optical focal length of the first lens to the thirteenth lens along the X direction, f1X represents the comprehensive optical focal length of the first lens along the X direction, f(2-11)X represents the comprehensive optical focal length of the second lens to the eleventh lens along the X direction, and f(12-13)X represents the comprehensive optical focal length of the twelfth lens to the thirteenth lens along the X direction; The sixth lens, the seventh lens, the ninth lens and the thirteenth lens are spherical lenses with negative optical power, and the fourth lens, the fifth lens, the eighth lens, the tenth lens, the eleventh lens and the twelfth lens are spherical lenses with positive optical power.

2. The anamorphic lens according to claim 1, wherein: The second lens and the third lens are cemented together.

3. The anamorphic lens according to claim 1, wherein: The fifth lens and the sixth lens are cemented together.

4. The anamorphic lens according to claim 1, wherein: The seventh lens and the eighth lens are cemented together.

5. The anamorphic lens according to claim 1, wherein: The length of the anamorphic lens is less than 120 mm.

6. The anamorphic lens according to claim 5, characterized in that: The front end of the anamorphic lens is matched with a 67mm filter.

7. The anamorphic lens according to claim 1, wherein: The focal length of the anamorphic lens along the Y direction is 75 mm, the focal length along the X direction is 56.4 mm, and the aperture is 1.

8.

8. The anamorphic lens according to claim 1, wherein: The mass of the anamorphic lens is less than 700g.

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