Ultra-large aperture full-frame camera lens

Abstract

The utility model discloses a full-frame camera lens with an ultra-large aperture. The full-frame camera lens sequentially comprises a first lens group, an iris diaphragm, a second lens group and a third lens group from an object side to an imaging surface, the first lens group serves as a fixed group, has negative focal power and comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens; the second lens group is used as a focusing group, has negative focal power, and is used as a focusing compensation group to move towards an imaging surface when focusing is carried out from an infinite distance to a near position; according to the utility model, the positive lens and the negative lens are matched and the aspheric lens is used, so that aberration is effectively corrected, the F1.4 maximum aperture is realized, excellent performance can be obtained, imaging at infinity and close-up distance is excellent, and part of ghosting in a picture is effectively eliminated through calculation; the structure is short and light, the moving group only comprises two lenses, the weight and the moving stroke of the moving group are obviously reduced, and the focusing efficiency is effectively guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of camera lens technology, specifically to a large aperture full-frame camera lens. Background Technology

[0002] The amount of light entering a lens is a crucial parameter affecting a photographer's success rate and image quality. A larger amount of light allows for shorter exposure times, resulting in more stable and reliable images. The amount of light entering a lens is expressed by its aperture value. A smaller aperture value not only allows for more light but also a shallower depth of field. Currently, the maximum aperture of most full-frame large-aperture lenses on the market is F1.8. However, ultra-large aperture lenses above F1.8 suffer from drawbacks such as high price and bulky size. Therefore, this invention designs an ultra-large aperture full-frame camera lens to improve upon these issues. Utility Model Content

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a large-aperture full-frame camera lens that can effectively correct aberrations, achieve superior performance, effectively eliminate some ghosting in the image through calculation, has a compact and lightweight structure, significantly reduces the weight and travel of the moving parts, and effectively ensures focusing efficiency.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A large aperture full-frame camera lens, from the object side to the imaging plane, includes a first lens group, a variable aperture, a second lens group, and a third lens group in sequence.

[0006] The first lens group is a fixed group with negative optical power, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens;

[0007] The second lens group, as a focusing group, has negative optical power and includes the ninth and tenth lenses. When focusing from infinity to near, the second lens group moves towards the imaging plane as a focus compensation group.

[0008] The third lens group, as a fixed group, has positive optical power and includes the eleventh lens, the twelfth lens, the thirteenth lens, and the fourteenth lens.

[0009] Preferably, the first lens group contains at least two regular-shaped air gaps, wherein the shape of the air gap closest to the object side satisfies the following condition:

[0010] 4.0<(A1 R2+A1 R1) / (A1 R2-A1 R1)<6.0

[0011] Where A1R1 is the radius of curvature of the side of the air gap closest to the object, and A1R2 is the radius of curvature of the side of the air gap closest to the object.

[0012] Preferably, the shape of the air gap closest to the object satisfies the following condition:

[0013] -0.5<(A2R2+A2R1) / (A2R2-A2R1)<1.5

[0014] Wherein, A1R1 is the radius of curvature of the second closest air gap object side to the object, and A1R2 is the radius of curvature of the second closest air gap image side to the object.

[0015] Preferably, at least two lenses in the first lens group satisfy the following condition:

[0016] ndGn≥1.8

[0017] Where ndGn is the refractive index of the lens material.

[0018] Preferably, the last lens in the first lens group G1 is a biconvex positive lens, satisfying the following condition:

[0019] 0.4 <FG1 / F8<2.2

[0020] Wherein, FG1 is the focal length of the first lens group G1, and F8 is the focal length of the last lens in the first lens group G1.

[0021] Preferably, during the focusing process from infinity to near distance, the second lens group moves closer to the imaging plane from the direction closer to the object, and the second lens group satisfies the following condition:

[0022] -6.3 <FG2 / f<-4.2

[0023] Where FG2 is the focal length of the first lens group, and f is the focal length of the camera lens optical system. Preferably, the second lens group G2 includes two lenses, and the lens materials satisfy the following conditions:

[0024] G10Nd-G9Nd<0.2

[0025] G9Vd-G10Vd>3

[0026] Wherein, G9Nd is the refractive index of the first lens in the second lens group G2, G10Nd is the refractive index of the second lens in the second lens group G2, G9Vd is the Abbe number of the first lens in the second lens group G2, and G10Vd is the Abbe number of the second lens in the second lens group G2.

[0027] Preferably, the third lens group contains a biconvex air gap that satisfies the following condition:

[0028] -0.5<(A10R2+A10R1) / (A10R2-A10R1)<1.5

[0029] Wherein, A10R1 is the radius of curvature of the side of the biconvex air gap near the object side in the third lens group, and A10R2 is the radius of curvature of the side of the biconvex air gap near the imaging plane in the third lens group.

[0030] Preferably, the third lens group includes a set of cemented lenses, each cemented lens comprising a positive lens and a negative lens, satisfying the following conditions:

[0031] G13Nd-G12Nd<0.3

[0032] G12Vd-G13Vd>35

[0033] Wherein, G12Nd is the refractive index of the positive lens in the cemented lens, G13Nd is the refractive index of the negative lens in the cemented lens, G12Vd is the Abbe number of the positive lens in the cemented lens, and G13Vd is the Abbe number of the negative lens in the cemented lens.

[0034] Compared with the prior art, the beneficial effects of this utility model are:

[0035] This invention utilizes a combination of positive and negative lenses and aspherical lenses to effectively correct aberrations. While achieving a maximum aperture of F1.4, it also achieves superior performance, providing excellent imaging at infinity and close distances. Through calculation, it effectively eliminates some ghosting in the image. The structure is compact and lightweight, with the moving group containing only two lenses, significantly reducing the weight and travel of the moving group, thus effectively ensuring focusing efficiency. Attached Figure Description

[0036] Figure 1 A schematic diagram of the lens structure of a large aperture full-frame camera lens;

[0037] Figure 2 A graph showing the spherical aberration curves of a lens for a large-aperture full-frame camera;

[0038] Figure 3 A field curvature curve diagram for a large aperture full-frame camera lens;

[0039] Figure 4 This is a distortion curve diagram for a large-aperture full-frame camera lens.

[0040] In the diagram: G1, first lens group; G2, second lens group; G3, third 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. Detailed Implementation

[0041] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0042] Example:

[0043] Please see Figure 1 This embodiment provides a large aperture full-frame camera lens, which includes a first lens group G1, a variable aperture, a second lens group G2 and a third lens group G3 in sequence from the object side to the imaging plane;

[0044] The first lens group G1 is a fixed group with negative optical power, including the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7 and the eighth lens 8, where the eighth lens 8 is an aspherical lens.

[0045] The second lens group G2 serves as the focusing group and has negative optical power. It includes the ninth lens 9 and the tenth lens 10. When focusing from infinity to near, the second lens group G2 moves towards the imaging plane as a focus compensation group (moving group).

[0046] The third lens group G3 is a fixed group with positive optical power, including the eleventh lens 11, the twelfth lens 12, the thirteenth lens 13 and the fourteenth lens 14. The eleventh lens 11 and the fourteenth lens 14 are aspherical lenses. The number of lenses in the first lens group G1, the second lens group G2 and the third lens group G3 is designed according to the design and usage requirements. Adding or removing the number of lenses is within the protection scope of this utility model.

[0047] In this embodiment, the first lens group G1 contains at least two positively shaped air gaps, wherein the shape of the air gap closest to the object side satisfies the following condition:

[0048] 4.0<(A1 R2+A1 R1) / (A1 R2-A1 R1)<6.0

[0049] Where A1R1 is the radius of curvature of the side of the air gap closest to the object, and A1R2 is the radius of curvature of the side of the air gap closest to the object.

[0050] In this embodiment, the first lens group G1 contains at least two positively shaped air gaps, wherein the shape of the second air gap closest to the object side satisfies the following condition:

[0051] -0.5<(A2R2+A2R1) / (A2R2-A2R1)<1.5

[0052] Wherein, A1R1 is the radius of curvature of the second closest air gap object side to the object, and A1R2 is the radius of curvature of the second closest air gap image side to the object.

[0053] In this embodiment, at least two lenses in the first lens group G1 satisfy the following condition:

[0054] ndGn≥1.8

[0055] Where ndGn is the refractive index of the lens material.

[0056] In this embodiment, the last lens in the first lens group G1 (i.e., the eighth lens 8) is a biconvex positive lens, satisfying the following condition:

[0057] 0.4 <FG1 / F8<2.2

[0058] Wherein, FG1 is the focal length of the first lens group G1, and F8 is the focal length of the last lens (eighth lens 8) in the first lens group G1.

[0059] In this embodiment, during the focusing process from infinity to near distance, the second lens group G2 moves closer to the imaging plane from the direction closer to the object, and the second lens group G2 satisfies the following conditions:

[0060] -6.3 <FG2 / f<-4.2

[0061] Where FG2 is the focal length of the first lens group G1, and f is the focal length of the camera lens optical system.

[0062] In this embodiment, the second lens group G2 includes two lenses (i.e., the ninth lens 9 and the tenth lens 10), and the lens materials satisfy the following conditions:

[0063] G10Nd-G9Nd<0.2

[0064] G9Vd-G10Vd>3

[0065] Wherein, G9Nd is the refractive index of the first lens (ninth lens 9) in the second lens group G2, G10Nd is the refractive index of the second lens (tenth lens 10) in the second lens group G2, G9Vd is the Abbe number of the first lens (ninth lens 9) in the second lens group (G2), and G10Vd is the Abbe number of the second lens (tenth lens 10) in the second lens group (G2).

[0066] In this embodiment, the third lens group G3 contains a biconvex air gap that satisfies the following condition:

[0067] -0.5<(A10R2+A10R1) / (A10R2-A10R1)<1.5

[0068] Wherein, A10R1 is the radius of curvature of the biconvex air gap in the third lens group G3 on the side closest to the object, and A10R2 is the radius of curvature of the biconvex air gap in the third lens group G3 on the side closest to the imaging plane.

[0069] In this embodiment, the third lens group G3 contains a set of cemented lenses, which includes a positive lens and a negative lens, satisfying the following conditions:

[0070] G13Nd-G12Nd<0.3

[0071] G12Vd-G13Vd>35

[0072] Wherein, G12Nd is the refractive index of the positive lens in the cemented lens, G13Nd is the refractive index of the negative lens in the cemented lens, G12Vd is the Abbe number of the positive lens in the cemented lens, and G13Vd is the Abbe number of the negative lens in the cemented lens.

[0073] As a preferred embodiment of the technical solution, the parameters of the camera lens embodiment are shown in Table 1 below. The aspherical coefficients of the aspherical lens are shown in Table 2 below. The surface number column shows the surface number when the surface closest to the object is designated as surface 1, and the numbering increases sequentially towards the imaging surface. The shape parameters of each lens element are also shown.

[0074] Table 1

[0075]

[0076]

[0077] Table 2

[0078]

[0079] As a preferred technical solution, the positions of the focus compensation group (movement group) of the camera lens under different focusing states in this embodiment are shown in Table 3 below, which are the values ​​of the two states D1 and D2 in Table 1:

[0080] Table 3

[0081] Conjugate distance Infinity The closest (0.45m) D1 1.54mm 12.89mm D2 14.64mm 3.29mm

[0082] As a preferred technical solution, the physical parameters of the camera lens in this embodiment are shown in Table 4 below:

[0083] Table 4

[0084]

[0085]

[0086] Figure 2 This is a spherical aberration curve of the camera lens in this embodiment. Figure 3 This is a field curvature curve diagram of the camera lens in this embodiment. Figure 4 The image shows the distortion curve of the camera lens in this embodiment. As can be seen, the camera lens in this embodiment has good imaging effect.

[0087] In this embodiment, by using the above-mentioned conditional constraints and employing a combination of positive and negative lenses and aspherical lenses, aberrations are effectively corrected. While achieving a maximum aperture of F1.4, superior performance can be obtained, resulting in excellent imaging at infinity and close distances. Through calculation, some ghosting in the image is effectively eliminated. The structure is compact and lightweight, with the moving group containing only two lenses, significantly reducing the weight and travel of the moving group, and effectively ensuring focusing efficiency.

[0088] The above embodiments are preferred implementations of this utility model. In addition, this utility model can also be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this utility model.

Claims

1. A large aperture full-frame camera lens, characterized in that: From the object side to the imaging plane, the lens group consists of a first lens group (G1), a variable aperture, a second lens group (G2), and a third lens group (G3). The first lens group (G1) is a fixed group with positive optical power, including 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) and an eighth lens (8); The second lens group (G2) serves as a focusing group with negative optical power, including the ninth lens (9) and the tenth lens (10). When focusing from infinity to near, the second lens group (G2) moves towards the imaging plane as a focusing compensation group. The third lens group (G3) is a fixed group with positive optical power, including the eleventh lens (11), the twelfth lens (12), the thirteenth lens (13) and the fourteenth lens (14); The first lens group (G1) contains at least two positively shaped air gaps, wherein the shape of the air gap closest to the object side satisfies the following condition: 4.0<(A1 R2+A1 R1) / (A1 R2-A1 R1)<6.0 Where A1 R1 is the radius of curvature of the side of the air gap closest to the object, and A1 R2 is the radius of curvature of the side of the air gap closest to the object. The shape of the second closest air gap to the object satisfies the following condition: -0.5<(A2R2+A2R1) / (A2R2-A2R1)<1.5 Wherein, A1R1 is the radius of curvature of the second closest air gap object side to the object, and A1R2 is the radius of curvature of the second closest air gap image side to the object.

2. The large aperture full-frame camera lens according to claim 1, characterized in that: At least two lenses in the first lens group (G1) satisfy the following condition: ndGn≥1.8 Where ndGn is the refractive index of the lens material.

3. The large aperture full-frame camera lens according to claim 1, characterized in that: The last lens in the first lens group (G1) is a biconvex positive lens, satisfying the following condition: 0.4 <FG1 / F8<2.2 Wherein, FG1 is the focal length of the first lens group (G1), and F8 is the focal length of the last lens in the first lens group (G1).

4. The large aperture full-frame camera lens according to claim 1, characterized in that: During the focusing process from infinity to near distance, the second lens group (G2) moves closer to the image plane from the direction closer to the object, and the second lens group (G2) satisfies the following conditions: -6.3 <FG2 / f<-4.2 Wherein, FG2 is the focal length of the first lens group (G1), and f is the focal length of the camera lens optical system.

5. A large aperture full-frame camera lens according to claim 1, characterized in that: The second lens group (G2) comprises two lenses, the lens materials of which satisfy the following conditions: G10Nd-G9Nd<0.2 G9Vd-G10Vd>3 Wherein, G9Nd is the refractive index of the first lens in the second lens group (G2), G10Nd is the refractive index of the second lens in the second lens group (G2), G9Vd is the Abbe number of the first lens in the second lens group (G2), and G10Vd is the Abbe number of the second lens in the second lens group (G2).

6. The large aperture full-frame camera lens according to claim 1, characterized in that: The third lens group (G3) contains a biconvex air gap that satisfies the following condition: -0.5<(A10R2+A10R1) / (A10R2-A10R1)<1.5 Wherein, A10R1 is the radius of curvature of the biconvex air gap in the third lens group (G3) on the side closest to the object, and A10R2 is the radius of curvature of the biconvex air gap in the third lens group (G3) on the side closest to the imaging plane.

7. A large aperture full-frame camera lens according to claim 1, characterized in that: The third lens group (G3) contains a set of cemented lenses, which includes a positive lens and a negative lens, satisfying the following conditions: G13Nd-G12Nd<0.3 G12Vd-G13Vd>35 Wherein, G12Nd is the refractive index of the positive lens in the cemented lens, G13Nd is the refractive index of the negative lens in the cemented lens, G12Vd is the Abbe number of the positive lens in the cemented lens, and G13Vd is the Abbe number of the negative lens in the cemented lens.

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