Wide-angle ultra-large-aperture full-frame camera lens

Abstract

The utility model discloses a wide-angle ultra-large-aperture full-frame camera lens, which sequentially comprises a first lens group, a second lens group, an iris diaphragm, a third lens group and a fourth lens group from an object side to an imaging surface, and is characterized in that the first lens group is used as a fixed group and has negative focal power; comprising a first lens, a second lens, a third lens, a fourth lens and a fifth lens, the second lens group serves as a focusing group and has negative focal power, the second lens group comprises a sixth lens, and the second lens group serves as a focusing compensation group to move towards the object space when focusing from infinity to a near position; according to the utility model, aberration is effectively corrected, F1.4 maximum aperture is realized, excellent performance can be obtained, imaging at infinity and close-up distance is excellent, part of ghosting in a picture is effectively eliminated through calculation, distortion is less than 2%, the structure is short, small and light, the moving group only comprises one lens, the weight and the moving stroke of the moving group are obviously reduced, and the cost is reduced. And the focusing efficiency is effectively ensured.

Description

Technical Field

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

[0002] Night scene and astrophotography have always been popular subjects in the photography industry. However, due to the low light levels at night, the resulting images often suffer from noise or blurriness caused by long exposures. Therefore, photographers need to choose lenses with sufficiently large apertures to meet the requirements for image sharpness and clarity. Currently, the maximum aperture of most full-frame large-aperture lenses on the market is F1.8, while ultra-large aperture lenses above F1.8 are expensive and bulky. Therefore, this invention designs a wide-angle ultra-large aperture full-frame camera lens to improve upon these problems. Utility Model Content

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a wide-angle, ultra-large aperture full-frame camera lens that can effectively correct aberrations, greatly reduce discomfort during video shooting, improve the photography experience, 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, the present invention provides the following technical solutions:

[0005] A wide-angle, ultra-large aperture full-frame camera lens, comprising, from the object side to the imaging plane, a first lens group, a second lens group, a variable aperture, a third lens group, and a fourth lens group;

[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, and a fifth lens;

[0007] The second lens group, as a focusing group, has negative optical power and includes a sixth lens. When focusing from infinity to near, the second lens group, as a focus compensation group, moves toward the object side.

[0008] The third lens group, as a fixed group, has positive optical power and includes a seventh lens, an eighth lens, a ninth lens, a tenth lens, and an eleventh lens.

[0009] The fourth lens group includes the twelfth lens, the thirteenth lens, the fourteenth lens, and the fifteenth lens.

[0010] Preferably, the first lens and the second lens are meniscus negative lenses that bend toward the image plane, satisfying the following conditions:

[0011] D1>7mm

[0012] 1.31 <F2 / F1<2.52

[0013] Where D1 is the center distance between the first lens and the second lens, F1 is the focal length of the first lens, and F2 is the focal length of the second lens.

[0014] Preferably, the first lens group contains a combination of positive and negative lenses, satisfying the following conditions:

[0015] D3<1mm

[0016] Vd4-Vd3>27

[0017] Wherein, D3 is the center interval of the positive and negative lens combination in the first lens group, Vd4 is the Abbe number of the negative lens in the positive and negative lens combination in the first lens group, and Vd3 is the Abbe number of the positive lens in the positive and negative lens combination in the first lens group.

[0018] Preferably, the focal length and position of the first lens group satisfy the following conditions:

[0019] 1.8mm < |FG1×si nθ| - TL1 < 9.1mm

[0020] Wherein, FG1 is the focal length of the first lens group, θ is half of the maximum field of view of the camera lens optical system, and TL1 is the distance from the vertex of the front end of the first lens to the variable aperture.

[0021] Preferably, the second lens group is a single negative lens bent towards the object surface, satisfying the following conditions:

[0022] -3.14 <F6 / f<-1.38

[0023] Where F6 is the focal length of the negative lens, and f is the focal length of the camera lens optical system.

[0024] Preferably, the first lens in the third lens group is a biconvex aspherical glass lens, satisfying the following conditions:

[0025] 0.68 <F7 / f<2.33

[0026] Wherein, F7 is the focal length of the first lens in the third lens group, and f is the focal length of the camera lens optical system.

[0027] Preferably, the last lens in the third lens group is a biconvex glass spherical lens, satisfying the following conditions:

[0028] 0.63<(F7×F11) / [f×(F7+F11-d)]<0.75

[0029] Wherein, F7 is the focal length of the first lens in the third lens group, F11 is the focal length of the last lens in the third lens group, d is the interval between the first and last lenses in the third lens group, and f is the focal length of the camera lens optical system.

[0030] Preferably, the last lens in the fourth lens group is a meniscus aspherical lens that bends towards the object side, and it satisfies the following conditions:

[0031] |F15|>300mm

[0032] T15≥3mm

[0033] Wherein, F15 is the focal length of the last lens in the fourth lens group, and T15 is the center thickness of the last lens in the fourth lens group.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] Effective aberration correction achieves superior performance while maintaining a maximum aperture of F1.4, resulting in excellent imaging at infinity and close-up distances. Calculations effectively eliminate some ghosting in the image, with distortion less than 2%. By selecting a movement group that satisfies low breathing effect and adjusting the light incident position, length, and positive / negative power ratio of the movement group, the system smoothly changes the angle of view when switching between near and far shooting, greatly reducing discomfort during video shooting and improving the photography experience. The compact and lightweight structure, with the movement group containing only one lens, significantly reduces the weight and movement distance of the movement group, effectively ensuring focusing efficiency. Attached Figure Description

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

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

[0038] Figure 3 Field curvature curve of a wide-angle, large-aperture full-frame camera lens;

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

[0040] In the diagram: G1, first lens group; G2, second lens group; G3, third lens group; G4, fourth 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. 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 wide-angle, ultra-large aperture full-frame camera lens, which includes, from the object side to the imaging plane, a first lens group G1, a second lens group G2, a variable aperture, a third lens group G3, and a fourth lens group G4.

[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 and the fifth lens 5, where the fifth lens 5 is a glass aspherical lens.

[0045] The second lens group G2 serves as a focusing group with negative optical power. It includes the sixth lens 6. When focusing from infinity to near, the second lens group G2 moves towards the object as a focus compensation group (moving group).

[0046] The third lens group G3 is a fixed group with positive optical power, including the seventh lens 7, the eighth lens 8, the ninth lens 9, the tenth lens 10 and the eleventh lens 11.

[0047] The fourth lens group G4 includes the twelfth lens 12, the thirteenth lens 13, the fourteenth lens 14, and the fifteenth lens 15. The number of lenses in the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 is designed according to design and usage requirements. Adding or removing the number of lenses is within the protection scope of this utility model.

[0048] In this embodiment, the first lens 1 and the second lens 2 are meniscus negative lenses that bend toward the image plane, satisfying the following conditions:

[0049] D1>7mm

[0050] 1.31 <F2 / F1<2.52

[0051] Where D1 is the center interval between the first lens 1 and the second lens 2, F1 is the focal length of the first lens 1, and F2 is the focal length of the second lens 2.

[0052] In this embodiment, the first lens group G1 contains a combination of positive and negative lenses, satisfying the following conditions:

[0053] D3<1mm

[0054] Vd4-Vd3>27

[0055] Wherein, D3 is the center interval of the positive and negative lens combination in the first lens group G1, Vd4 is the Abbe number of the negative lens in the positive and negative lens combination in the first lens group G1, and Vd3 is the Abbe number of the positive lens in the positive and negative lens combination in the first lens group G1.

[0056] In this embodiment, the focal length and position of the first lens group G1 satisfy the following conditions:

[0057] 1.8mm < |FG1×si nθ| - TL1 < 9.1mm

[0058] Wherein, FG1 is the focal length of the first lens group G1, θ is half of the maximum field of view of the camera lens optical system, and TL1 is the distance from the front vertex of the first lens 1 to the variable aperture.

[0059] In this embodiment, the second lens group G2 is a single negative lens bent towards the object surface, satisfying the following conditions:

[0060] -3.14 <F6 / f<-1.38

[0061] Where F6 is the focal length of the negative lens, and f is the focal length of the camera lens optical system.

[0062] In this embodiment, the first lens (i.e., the seventh lens 7) in the third lens group G3 is a biconvex aspherical glass lens that satisfies the following conditions:

[0063] 0.68 <F7 / f<2.33

[0064] Wherein, F7 is the focal length of the first lens (seventh lens 7) in the third lens group G3, and f is the focal length of the camera lens optical system.

[0065] In this embodiment, the last lens in the third lens group G3 (i.e., the eleventh lens 11) is a biconvex glass spherical lens that satisfies the following conditions:

[0066] 0.63<(F7×F11) / [f×(F7+F11-d)]<0.75

[0067] Wherein, F7 is the focal length of the first lens (seventh lens 7) in the third lens group G3, F11 is the focal length of the last lens (eleventh lens 11) in the third lens group G3, d is the interval between the first lens (seventh lens 7) and the last lens (eleventh lens 11) in the third lens group G3, and f is the focal length of the camera lens optical system.

[0068] In this embodiment, the last lens in the fourth lens group G4 (i.e., the fifteenth lens 15) is a meniscus aspherical lens that curves towards the object side, and it satisfies the following conditions:

[0069] |F15|>300mm

[0070] T15≥3mm

[0071] Wherein, F15 is the focal length of the last lens (fifteenth lens 15) in the fourth lens group G4, and T15 is the center thickness of the last lens (fifteenth lens 15) in the fourth lens group G4.

[0072] 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.

[0073] Table 1

[0074]

[0075]

[0076] Table 2

[0077]

[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 Most recently (0.3m) D1 6.74mm 2.74mm D2 2.72mm 6.72mm

[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] Focal length f 24.08mm Relative aperture FNO. 1.46 Field of view ω 83.9° Overall optical length 123mm

[0085] 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.

[0086] In this embodiment, by limiting the above-mentioned conditional expressions, aberrations are effectively corrected, achieving a maximum aperture of F1.4 while obtaining superior performance. It exhibits excellent imaging at infinity and close-up distances, effectively eliminating some ghosting in the image through calculation, with distortion less than 2%. By calculating and selecting a moving group that satisfies the low breathing effect, and adjusting the light incident position and length of the moving group as well as the ratio of positive and negative optical power, the system makes the angle change during switching between near and far shooting tend to be smooth, greatly reducing the discomfort of video shooting and improving the photography experience. The structure is compact and lightweight, with the moving group containing only one lens, significantly reducing the weight and movement distance of the moving group, and effectively ensuring focusing efficiency.

[0087] 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 wide-angle, large-aperture full-frame camera lens, characterized in that: From the object plane to the imaging plane, the lens group consists of the first lens group (G1), the second lens group (G2), the variable aperture, the third lens group (G3), and the fourth lens group (G4). The first lens group (G1) is a fixed group with negative optical power, including a first lens (1), a second lens (2), a third lens (3), a fourth lens (4) and a fifth lens (5); The second lens group (G2) serves as a focusing group and has negative optical power. When the sixth lens (6) focuses from infinity to near, the second lens group (G2) serves as a focusing compensation group and moves toward the object. The third lens group (G3) is a fixed group with positive optical power, including the seventh lens (7), the eighth lens (8), the ninth lens (9), the tenth lens (10) and the eleventh lens (11); The fourth lens group (G4) includes the twelfth lens (12), the thirteenth lens (13), the fourteenth lens (14), and the fifteenth lens (15).

2. The wide-angle, large-aperture full-frame camera lens according to claim 1, characterized in that: The first lens (1) and the second lens (2) are meniscus negative lenses that bend toward the image plane and satisfy the following conditions: D1>7mm 1.31 <F2 / F1<2.52 Wherein, D1 is the center interval between the first lens (1) and the second lens (2), F1 is the focal length of the first lens (1), and F2 is the focal length of the second lens (2).

3. A wide-angle, large-aperture full-frame camera lens according to claim 1, characterized in that: The first lens group (G1) contains a combination of positive and negative lenses that satisfies the following conditions: D3<1mm Vd4-Vd3>27 Wherein, D3 is the center interval of the positive and negative lens combination in the first lens group (G1), Vd4 is the Abbe number of the negative lens in the positive and negative lens combination in the first lens group (G1), and Vd3 is the Abbe number of the positive lens in the positive and negative lens combination in the first lens group (G1).

4. A wide-angle, large-aperture full-frame camera lens according to claim 1, characterized in that: The focal length and position of the first lens group (G1) satisfy the following conditions: 1.8mm < |FG1×sinθ|-TL1 < 9.1mm Wherein, FG1 is the focal length of the first lens group (G1), θ is half of the maximum field of view of the camera lens optical system, and TL1 is the distance from the front vertex of the first lens (1) to the variable aperture.

5. A wide-angle, large-aperture full-frame camera lens according to claim 1, characterized in that: The second lens group (G2) is a single negative lens bent towards the object surface, satisfying the following conditions: -3.14 <F6 / f<-1.38 Where F6 is the focal length of the negative lens, and f is the focal length of the camera lens optical system.

6. A wide-angle, large-aperture full-frame camera lens according to claim 1, characterized in that: The first lens in the third lens group (G3) is a biconvex aspherical glass lens that satisfies the following conditions: 0.68 <F7 / f<2.33 Wherein, F7 is the focal length of the first lens in the third lens group (G3), and f is the focal length of the camera lens optical system.

7. A wide-angle, large-aperture full-frame camera lens according to claim 6, characterized in that: The last lens in the third lens group (G3) is a biconvex glass spherical lens that satisfies the following conditions: 0.63<(F7×F11) / [f×(F7+F11-d)]<0.75 Wherein, F7 is the focal length of the first lens in the third lens group (G3), F11 is the focal length of the last lens in the third lens group (G3), d is the interval between the first and last lenses in the third lens group (G3), and f is the focal length of the camera lens optical system.

8. A wide-angle, large-aperture full-frame camera lens according to claim 1, characterized in that: The last lens in the fourth lens group (G4) is a meniscus aspherical lens that curves towards the object side, and it satisfies the following conditions: |F15|>300mm T15≥3mm Wherein, F15 is the focal length of the last lens in the fourth lens group (G4), and T15 is the center thickness of the last lens in the fourth lens group (G4).

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