Ultra-large aperture standard focal length full-frame camera lens

Abstract

The utility model discloses a full-frame camera lens with an ultra-large aperture and a standard focal length. 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 positive 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 and has negative focal power, and when the second lens group is focused from infinity to a near position, the second lens group is used as a focusing compensation group to move towards an imaging surface; according to the utility model, aberration is effectively corrected, excellent performance can be obtained while the F1.4 maximum aperture is realized, imaging is excellent at infinity and close-up distance, 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 standard focal length 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 standard focal length 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 full-frame camera lens with a super-large aperture and standard focal length, comprising, from the object side to the imaging plane, a first lens group, a variable aperture, a second lens group, and a third lens group;

[0006] The first lens group, as a fixed group, has positive optical power and includes 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] The first lens group contains a biconvex air gap that satisfies the following condition:

[0010] -0.5<(A3R2+A3R1) / (A3R2-A3R1)<1.5

[0011] Wherein, A3R1 is the radius of curvature of the side of the biconvex air gap in the first lens group closest to the object side, and A3R2 is the radius of curvature of the side of the biconvex air gap in the first lens group closest to the imaging surface.

[0012] Preferably, the first lens is a meniscus negative lens that bends toward the image plane, satisfying the following conditions:

[0013] -4<(G1R2+G1 R1) / (G1R2-G1R1)<-2

[0014] Wherein, G1R1 is the radius of curvature of the side of the first lens near the object side, and G1R2 is the radius of curvature of the side of the first lens near the imaging surface.

[0015] Preferably, the first lens group includes a biconvex aspherical glass lens that satisfies the following conditions:

[0016] 0.8 <f / F5<2.8

[0017] Wherein, F5 is the focal length of the first lens group's biconvex aspherical glass lens, and f is the focal length of the camera lens optical system.

[0018] Preferably, the second lens group consists of a biconcave lens and a biconvex lens, satisfying the following conditions:

[0019] 1<|F10| / |F9|<3

[0020] Wherein, F9 is the focal length of the biconcave lens in the second lens group, and F10 is the focal length of the biconvex lens in the second lens group.

[0021] Preferably, the third lens group contains a biconvex air gap that satisfies the following condition:

[0022] -0.5<(A12R2+A12R1) / (A12R2-A12R1)<1.5

[0023] Wherein, A12R1 is the radius of curvature of the side of the biconvex air gap near the object side in the third lens group, and A12R2 is the radius of curvature of the side of the biconvex air gap near the imaging plane in the third lens group.

[0024] Preferably, the last lens in the third lens group satisfies the following condition:

[0025] -4 <F14 / f<-2

[0026] -2.5 <F14 / FG3<-0.5

[0027] Wherein, F14 is the focal length of the last lens in the third lens group, FG3 is the focal length of the third lens group, and f is the focal length of the camera lens optical system.

[0028] Compared with the prior art, the beneficial effects of this utility model are:

[0029] 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

[0030] Figure 1 A schematic diagram of the lens structure for a full-frame camera lens with a super-large aperture and standard focal length;

[0031] Figure 2 A spherical aberration curve for a full-frame camera lens with a super-large aperture and standard focal length;

[0032] Figure 3 Field curvature curve of a full-frame camera lens with a standard focal length and ultra-large aperture;

[0033] Figure 4 This is a distortion curve diagram for a full-frame camera lens with a super-large aperture and standard focal length.

[0034] 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

[0035] 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.

[0036] Example:

[0037] Please see Figure 1This embodiment provides a large aperture standard focal length 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.

[0038] 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 fifth lens 5 is an aspherical lens.

[0039] 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).

[0040] 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.

[0041] The first lens group G1 contains a biconvex air gap that satisfies the following condition:

[0042] -0.5<(A3R2+A3R1) / (A3R2-A3R1)<1.5

[0043] Wherein, A3R1 is the radius of curvature of the side of the biconvex air gap in the first lens group G1 closest to the object side, and A3R2 is the radius of curvature of the side of the biconvex air gap in the first lens group G1 closest to the imaging surface.

[0044] In this embodiment, the first lens 1 is a meniscus negative lens that bends toward the image plane, satisfying the following conditions:

[0045] -4<(G1R2+G1 R1) / (G1R2-G1R1)<-2

[0046] Wherein, G1R1 is the radius of curvature of the side of the first lens 1 closest to the object, and G1R2 is the radius of curvature of the side of the first lens 1 closest to the imaging plane.

[0047] In this embodiment, the first lens group G1 contains a biconvex aspherical glass lens that satisfies the following conditions:

[0048] 0.8 <f / F5<2.8

[0049] Where F5 is the focal length of the first lens group G1 biconvex aspherical glass lens, and f is the focal length of the camera lens optical system.

[0050] In this embodiment, the second lens group G2 consists of a biconcave lens and a biconvex lens, satisfying the following conditions:

[0051] 1<|F10| / |F9|<3

[0052] Wherein, F9 is the focal length of the biconcave lens in the second lens group G2, and F10 is the focal length of the biconvex lens in the second lens group G2.

[0053] In this embodiment, the third lens group G3 contains a biconvex air gap that satisfies the following condition:

[0054] -0.5<(A12R2+A12R1) / (A12R2-A12R1)<1.5

[0055] Wherein, A12R1 is the radius of curvature of the biconvex air gap in the third lens group G3 on the side closest to the object, and A12R2 is the radius of curvature of the biconvex air gap in the third lens group G3 on the side closest to the imaging plane.

[0056] In this embodiment, the last lens in the third lens group G3 (i.e., the fourteenth lens 14) satisfies the following condition:

[0057] -4 <F14 / f<-2

[0058] -2.5 <F14 / FG3<-0.5

[0059] Where F14 is the focal length of the last lens (fourteenth lens 14) in the third lens group G3, FG3 is the focal length of the third lens group G3, and f is the focal length of the camera lens optical system.

[0060] 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.

[0061] Table 1

[0062]

[0063]

[0064] Table 2

[0065]

[0066] 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:

[0067] Table 3

[0068] Conjugate distance Infinity The closest (0.5m) D1 3.7mm 13.15mm D2 10.55mm 1.1mm

[0069] As a preferred technical solution, the physical parameters of the camera lens in this embodiment are shown in Table 4 below:

[0070] Table 4

[0071] Focal length f 48.24mm Relative aperture FNO. 1.45 Field of view ω 41.6° Overall optical length 122mm

[0072] 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.

[0073] 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.

[0074] 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 standard focal length 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 a biconvex air gap that satisfies the following condition: -0.5<(A3R2+A3R1) / (A3R2-A3R1)<1.5 Wherein, A3R1 is the radius of curvature of the biconvex air gap in the first lens group (G1) on the side closest to the object, and A3R2 is the radius of curvature of the biconvex air gap in the first lens group (G1) on the side closest to the imaging plane.

2. The large aperture standard focal length full-frame camera lens according to claim 1, characterized in that: The first lens (1) is a meniscus negative lens that bends toward the image plane and satisfies the following conditions: -4<(G1R2+G1 R1) / (G1R2-G1R1)<-2 Wherein, G1R1 is the radius of curvature of the side of the first lens (1) near the object side, and G1R2 is the radius of curvature of the side of the first lens (1) near the imaging surface.

3. The large aperture standard focal length full-frame camera lens according to claim 1, characterized in that: The first lens group (G1) contains a biconvex aspherical glass lens that satisfies the following conditions: 0.8 <f / F5<2.8 Wherein, F5 is the focal length of the first lens group (G1) biconvex aspherical glass lens, and f is the focal length of the camera lens optical system.

4. The large aperture standard focal length full-frame camera lens according to claim 1, characterized in that: The second lens group (G2) consists of one biconcave lens and one biconvex lens, satisfying the following conditions: 1<|F10| / |F9|<3 Wherein, F9 is the focal length of the biconcave lens in the second lens group (G2), and F10 is the focal length of the biconvex lens in the second lens group (G2).

5. A large aperture standard focal length 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<(A12R2+A12R1) / (A12R2-A12R1)<1.5 Wherein, A12R1 is the radius of curvature of the biconvex air gap in the third lens group (G3) on the side closest to the object, and A12R2 is the radius of curvature of the biconvex air gap in the third lens group (G3) on the side closest to the imaging plane.

6. The large aperture standard focal length full-frame camera lens according to claim 1, characterized in that: The last lens in the third lens group (G3) satisfies the following condition: -4 <F14 / f<-2 -2.5 <F14 / FG3<-0.5 Wherein, F14 is the focal length of the last lens in the third lens group (G3), FG3 is the focal length of the third lens group (G3), and f is the focal length of the camera lens optical system.

Images