Full-frame aerial photography prime lens

Abstract

The utility model provides a full-frame aerial photography prime lens. The full-frame aerial photography prime lens comprises a first lens group, a diaphragm, a focusing lens and a second lens group which are sequentially arranged from an object side to an image side, the focal power of the first lens group is positive; the aperture of the diaphragm can be adjusted; the focal power of the focusing lens is negative, and the focusing lens can move along the optical axis direction; the focal power of the second lens group is positive. The full-frame aerial photography prime lens provided by the utility model is compact in structure and low in manufacturing cost; large-aperture light of the lens can be received, the length of the lens is effectively controlled, and the design of small size and light weight is facilitated. Different aperture shooting and depth-of-field adjustment can be realized; the image quality can be uniform and stable in a relatively long shooting range; and the focal power of the second lens group is positive, so that a relatively large imaging picture and relatively high relative illumination can be realized.

Description

Technical Field

[0001] The present application belongs to the technical field of optical lenses, and more specifically, to a full-frame aerial photography fixed-focus lens. Background Art

[0002] With the development and progress of science and technology, drones are becoming more and more maneuverable, and they play various supporting roles in people's lives, such as agricultural irrigation, celebration shooting, and city shooting. The aerial camera lens carried by drones needs to be small and light with stable image quality. At present, there are some disadvantages in the aerial cameras on the market, such as large size, small imaging screen, limited shooting range, serious color difference, and heavy weight. At the same time, although a few highly competitive aerial cameras support large-surface shooting and are generally lighter and smaller, they also have problems such as low relative illumination and peripheral vignetting. Utility Model Content

[0003] The purpose of the embodiments of the present application is to provide a full-frame aerial photography fixed-focus lens to solve the technical problems in the prior art of small imaging frame, low image quality and high manufacturing cost while ensuring that the lens is small and lightweight.

[0004] To achieve the above-mentioned purpose, the technical solution adopted in the present application is: to provide a full-frame aerial photography fixed-focus lens, including: a first lens group, an aperture, a focusing lens and a second lens group arranged in sequence from the object side to the image side; the optical focal length of the first lens group is positive; the aperture of the aperture can be adjusted; the optical focal length of the focusing lens is negative, and the focusing lens can be moved along the optical axis; the optical focal length of the second lens group is positive.

[0005] Optionally, the first lens group includes at least three positive power lenses and at least one negative power lens; along the direction from the object side to the image side, the first lens in the first lens group is a positive power lens, and a surface close to the object side is a convex surface; the last lens in the first lens group has a concave surface close to the image side.

[0006] Optionally, in the first lens group, at least one negative power lens is glued to one positive power lens to form a first achromatic lens; in the first achromatic lens, the Abbe number and refractive index of the positive power lens and the negative power lens meet the following conditions:

[0007] Vd1-Vd2>20,Nd2-Nd1>0.2;

[0008] Among them, Vd1 is the Abbe number of the positive power lens, Vd2 is the Abbe number of the negative power lens, Nd1 is the refractive index of the positive power lens, and Nd2 is the refractive index of the negative power lens.

[0009] Optionally, in the first lens group, at least one positive power lens is an extra-low dispersion lens.

[0010] Optionally, the focal length of the first lens group and the focal length of the full-frame aerial photography fixed-focus lens satisfy the following conditional formula:

[0011] F1 / F≤0.82;

[0012] Among them, F1 is the focal length value of the first lens group; F is the focal length value of the full-frame aerial photography fixed-focus lens.

[0013] Optionally, a surface of the focusing lens close to the image side is a concave surface; when the object distance increases, the focusing lens moves toward the object side along the optical axis, and when the object distance decreases, the focusing lens moves toward the image side along the optical axis.

[0014] Optionally, the second lens group includes a plurality of lenses. Along the direction from the object side to the image side, the first lens in the second lens group is a positive power lens, the second lens is a negative power lens, and the first lens and the second lens are glued together to form a second achromatic lens; in the second achromatic lens, the Abbe number and the refractive index of the positive power lens and the negative power lens meet the following conditions:

[0015] Vd1'-Vd2'>20,Nd2'-Nd1'>0.2;

[0016] Wherein, Vd1' is the Abbe number of the positive power lens, Vd2' is the Abbe number of the negative power lens, Nd1' is the refractive index of the positive power lens, and Nd2' is the refractive index of the negative power lens.

[0017] Optionally, along the direction from the object side to the image side, the third lens in the second lens group is a negative power lens, the fourth lens is a positive power lens, the third lens and the fourth lens are cemented to form a cemented lens, and in the cemented lens, the Abbe number and refractive index of the positive power lens and the negative power lens satisfy the following conditions:

[0018] Nd3'>Nd4';

[0019] Wherein, Nd3' is the refractive index of the positive power lens, and Nd4' is the refractive index of the negative power lens.

[0020] Optionally, along the direction from the object side to the image side, in the second lens group, the fifth lens is a negative power lens, and a surface of the fifth lens close to the object side is a concave surface, and the sixth lens is a positive power lens.

[0021] Optionally, the focal length value and the total optical length of the full-frame aerial photography fixed-focus lens satisfy the following conditional formula:

[0022] L / F ≥ 0.78;

[0023] Among them, F is the focal length of the full-frame aerial photography fixed-focus lens, and L is the total optical length of the full-frame aerial photography fixed-focus lens.

[0024] The beneficial effects of the full-frame aerial photography fixed-focus lens provided in the present application are: compared with the prior art, in the present application, the full-frame aerial photography fixed-focus lens has a compact structure and low manufacturing cost; by adopting a first lens group with positive optical focal length, it is possible to collect light from a large aperture of the lens, effectively control the length of the lens, and facilitate a small and lightweight design; by setting an adjustable diaphragm aperture, different aperture shooting and depth of field adjustment can be achieved; by setting a focusing lens with negative optical focal length, uniform and stable image quality can be achieved within a longer shooting range; the optical focal length of the second lens group is positive, which can achieve a larger imaging frame and a higher relative illumination. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A 2D structural schematic diagram of a full-frame aerial photography fixed-focus lens provided in Example 1 of the present application;

[0027] Figure 2 This is the MTF diagram corresponding to 10lp / mm and 30lp / mm line pairs of the full-frame aerial photography fixed-focus lens provided in Example 1 of the present application;

[0028] Figure 3 This is a distortion diagram of the full-frame aerial photography fixed-focus lens provided in Example 1 of the present application;

[0029] Figure 4 A relative illumination diagram of a full-frame aerial photography fixed-focus lens provided in Example 1 of the present application;

[0030] Figure 5 A 2D structural schematic diagram of a full-frame aerial photography fixed-focus lens provided in Example 2 of the present application;

[0031] Figure 6 This is the MTF diagram corresponding to 10lp / mm and 30lp / mm line pairs of the full-frame aerial photography fixed-focus lens provided in Example 2 of the present application;

[0032] Figure 7 This is a distortion diagram of the full-frame aerial photography fixed-focus lens provided in Example 2 of the present application;

[0033] Figure 8 A relative illumination diagram of a full-frame aerial photography fixed-focus lens provided in Example 2 of the present application;

[0034] Fig. 9 A 2D structural diagram of a full-frame aerial photography fixed-focus lens provided in Example 3 of the present application;

[0035] Fig.10 This is the MTF diagram corresponding to 10lp / mm and 30lp / mm line pairs of the full-frame aerial photography fixed-focus lens provided in Example 3 of the present application;

[0036] Fig.11 This is a distortion diagram of the full-frame aerial photography fixed-focus lens provided in Example 3 of the present application;

[0037] Fig.12 This is a relative illumination diagram of the full-frame aerial photography fixed-focus lens provided in Example 3 of the present application.

[0038] Among them, the reference numerals in the figure are:

[0039] 100 - first lens group; 101 - first lens; 102 - second lens; 103 - third lens; 104 - fourth lens;

[0040] 200- aperture;

[0041] 300-focus lens;

[0042] 400 - second lens group; 401 - fifth lens; 402 - sixth lens; 403 - seventh lens; 404 - eighth lens; 405 - ninth lens; 406 - tenth lens. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0045] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0047] Please also read Figure 1 , Figure 5 and Fig. 9 The full-frame aerial photography fixed-focus lens provided by the embodiment of the present application is now described. The full-frame aerial photography fixed-focus lens comprises: a first lens group 100, an aperture 200, a focus lens 300, and a second lens group 400, which are arranged in sequence from the object side to the image side; the first lens group 100 has a positive focal length; the aperture of the aperture 200 can be adjusted; the focus lens 300 has a negative focal length, and the focus lens 300 can move along the optical axis; the second lens group 400 has a positive focal length. Figure 1 , Figure 5 and Fig. 9 In the figure, IMA is the image side.

[0048] Compared with the prior art, the full-frame aerial photography fixed-focus lens provided in the present application has a compact structure and low manufacturing cost in the present embodiment. By adopting the first lens group 100 with positive optical focal length, it is possible to collect light with a large aperture of the lens, effectively control the length of the lens, and facilitate a small and lightweight design. By setting an adjustable aperture of the diaphragm 200, different aperture shooting and depth of field adjustment can be achieved. By setting a focusing lens 300 with negative optical focal length, uniform and stable image quality can be achieved within a longer shooting range. The optical focal length of the second lens group 400 is positive, which can achieve a larger imaging frame and a higher relative illumination.

[0049] In one embodiment of the present application, the first lens group 100 includes at least three positive power lenses and at least one negative power lens; along the direction from the object side to the image side, the first lens in the first lens group 100 is a positive power lens, and a surface close to the object side is a convex surface; the last lens in the first lens group 100 has a concave surface close to the image side.

[0050] In this embodiment, a lens with positive focal length is used in the first lens group 100, so that a large aperture light can be collected, spherical aberration and part of vertical axis aberration can be effectively corrected, light height can be reduced, and system sensitivity can be reduced; a lens with negative focal length is used in the first lens group 100, so that the angle at which the edge light enters the aperture 200 can be reduced, and part of the vertical axis aberration can be balanced.

[0051] In one embodiment of the present application, in the first lens group 100, at least one negative power lens and one positive power lens are cemented together to form a first achromatic lens; in the first achromatic lens, the Abbe number and refractive index of the positive power lens and the negative power lens meet the following conditions:

[0052] Vd1-Vd2>20,Nd2-Nd1>0.2;

[0053] Among them, Vd1 is the Abbe number of the positive power lens, Vd2 is the Abbe number of the negative power lens, Nd1 is the refractive index of the positive power lens, and Nd2 is the refractive index of the negative power lens.

[0054] In this embodiment, the use of the first achromatic lens can effectively correct astigmatism. The Abbe number and refractive index of the two lens materials constituting the first achromatic lens meet the above conditions, which can effectively correct the spherical aberration of the system and improve the imaging quality. It can be understood that the key to the parameters lies in the relative size relationship between the refractive index and the Abbe number of the material between the two lenses. When the parameters do not meet the above conditions, the chromatic aberration of the system is in a state of under-correction or over-correction, and the lens is prone to overall color cast problems.

[0055] In one embodiment of the present application, in the first lens group 100 , at least one positive power lens is an extra-low dispersion lens.

[0056] In this embodiment, an ultra-low dispersion lens is used as a positive power lens, which can effectively correct the spherical aberration of the system. It can be understood that the ultra-low dispersion lens is a lens made of ultra-low dispersion material.

[0057] In one embodiment of the present application, the focal length of the first lens group 100 and the focal length of the full-frame aerial photography fixed-focus lens satisfy the following conditional formula:

[0058] F1 / F≤0.82;

[0059] Wherein, F1 is the focal length value of the first lens group 100; and F is the focal length value of the full-frame aerial photography fixed-focus lens.

[0060] In this embodiment, by adjusting the focal length of the first lens group 100 according to the above conditional expression, the total length of the system can be effectively controlled, the angle of light passing through the aperture 200 can be reduced, and the inter-group sensitivity of the optical system can be reduced.

[0061] In one embodiment of the present application, a surface of the focusing lens 300 close to the image side is concave; when the object distance increases, the focusing lens 300 moves toward the object side along the optical axis, and when the object distance decreases, the focusing lens 300 moves toward the image side along the optical axis.

[0062] In this embodiment, by moving the focus lens 300, the focal shift caused by the change of the object distance can be compensated, thereby meeting the needs of the photographer.

[0063] In one embodiment of the present application, the second lens group 400 includes a plurality of lenses. Along the direction from the object side to the image side, the first lens in the second lens group 400 is a positive power lens, and the second lens is a negative power lens. The first lens and the second lens are cemented together to form a second achromatic lens. In the second achromatic lens, the Abbe number and the refractive index of the positive power lens and the negative power lens satisfy the following conditions:

[0064] Vd1'-Vd2'>20,Nd2'-Nd1'>0.2;

[0065] Wherein, Vd1' is the Abbe number of the positive power lens, Vd2' is the Abbe number of the negative power lens, Nd1' is the refractive index of the positive power lens, and Nd2' is the refractive index of the negative power lens.

[0066] In this embodiment, the Abbe number and refractive index of the two lens materials constituting the second achromatic lens meet the above conditions, which can effectively correct the vertical axis chromatic aberration of the system and improve the imaging quality. It can be understood that the key to the parameters lies in the relative size relationship between the refractive index and the Abbe number of the material between the two lenses. When the parameters do not meet the above conditions, the chromatic aberration of the system is in a state of under-correction or over-correction, and the lens is prone to color fringing.

[0067] In one embodiment of the present application, along the direction from the object side to the image side, the third lens in the second lens group 400 is a negative power lens, the fourth lens is a positive power lens, the third lens and the fourth lens are cemented to form a cemented lens, and in the cemented lens, the Abbe number and the refractive index of the positive power lens and the negative power lens meet the following conditions:

[0068] Nd3'>Nd4';

[0069] Wherein, Nd3' is the refractive index of the positive power lens, and Nd4' is the refractive index of the negative power lens.

[0070] In this embodiment, a cemented lens is used to effectively correct coma and other perpendicular axis aberrations, thereby achieving uniform image quality from the center to the periphery of the image.

[0071] In one embodiment of the present application, along the direction from the object side to the image side, in the second lens group 400, the fifth lens is a negative power lens, and a surface of the fifth lens close to the object side is a concave surface, and the sixth lens is a positive power lens.

[0072] In this embodiment, the fifth lens and the sixth lens of the second lens group 400 are matched with the above-mentioned shapes, which can reduce the chief ray angle of the maximum field of view, achieve a larger frame and numerical aperture value, and improve relative illumination.

[0073] In one embodiment of the present application, the focal length value and the total optical length of the full-frame aerial photography fixed-focus lens satisfy the following conditional formula:

[0074] L / F ≥ 0.78;

[0075] Among them, F is the focal length of the full-frame aerial photography fixed-focus lens, and L is the total optical length of the full-frame aerial photography fixed-focus lens.

[0076] In this embodiment, L / F satisfies the above conditional expression to ensure the ratio of the optical system, thereby ensuring the volume requirement of the optical system and achieving the design requirement of small size and lightness.

[0077] Embodiment 1

[0078] The conditional data in this embodiment are shown in Table 1, and the parameters of each lens are shown in Table 2.

[0079] Table 1:

[0080] <![CDATA[F1 / F]]> 0.7 L / F 0.96

[0081] Table 2:

[0082]

[0083]

[0084] In this embodiment, the focal length value of the optical system is F=75.20, the aperture coefficient FNO=3.0, and the total optical length L=72.

[0085] See also Figure 1 The first lens group 100 includes a first lens 101, a second lens 102, a third lens 103 and a fourth lens 104 arranged in sequence from the object side to the image side. The second lens group 400 includes a fifth lens 401, a sixth lens 402, a seventh lens 403, an eighth lens 404, a ninth lens 405 and a tenth lens 406 arranged in sequence from the object side to the image side.

[0086] In this embodiment, the focal length of the first lens group 100 is F1=52.37, the optical power of the first lens 101, the second lens 102 and the fourth lens 104 is positive; the optical power of the third lens 103 is negative; the third lens 103 and the fourth lens 104 are cemented together to form a first achromatic lens; the refractive index and Abbe number of the third lens 103 are respectively: Nd=1.83; Vd=37.8; the refractive index and Abbe number of the fourth lens 104 are respectively: Nd=1.5; Vd=81.6; the second lens 102 and the fourth lens 104 are extra-low dispersion lenses.

[0087] In this embodiment, the fifth lens 401 and the sixth lens 402 are cemented to form a second achromatic lens; the refractive index and Abbe number of the fifth lens 401 are respectively: Nd=1.64; Vd=60.2; the refractive index and Abbe number of the sixth lens 402 are respectively: Nd=1.76; Vd=28; the seventh lens 403 and the eighth lens 404 are cemented to form a cemented lens; the refractive index of the seventh lens 403 is: Nd=1.84; the refractive index of the eighth lens 404 is: Nd=1.50.

[0088] See also Figure 2 , Figure 2 This is the MTF diagram of the full-frame aerial photography fixed-focus lens provided in Example 1 of the present application at 10lp / mm and 30lp / mm line pairs. The dotted line represents the sagittal direction, and the solid line represents the meridian direction. Figure 2 It can be seen that the MTF of the 0-0.9 field of view lens at 10lp / mm is greater than 0.85, and the MTF of the 0-0.9 field of view lens at 30lp / mm is greater than 0.6, and the imaging is uniform.

[0089] See also Figure 3 , Figure 3 This is the distortion diagram of the full-frame aerial photography fixed-focus lens provided in Example 1 of the present application. In the field of view angle vs distortion diagram corresponding to a wavelength of 546mm, the lens distortion is less than 1%.

[0090] See also Figure 4 , Figure 4 This is a relative illumination diagram of the full-frame aerial photography fixed-focus lens provided in Example 1 of the present application. The edge field illumination is >45%, and there is no dark corner.

[0091] Embodiment 2

[0092] The conditional data in this embodiment are shown in Table 3, and the parameters of each lens are shown in Table 4.

[0093] Table 3:

[0094] <![CDATA[F1 / F]]> 0.55 L / F 0.88

[0095] Table 4:

[0096]

[0097]

[0098] In this embodiment, the focal length value of the optical system is F=85.65, the aperture coefficient FNO=3.2, and the total optical length L=75.36.

[0099] The focal length value F1 of the first lens group 100 is 47.12; the optical power of the first lens 101, the second lens 102 and the fourth lens 104 is positive; the optical power of the third lens 103 is negative; the third lens 103 and the fourth lens 104 are cemented together to form a first achromatic lens; the refractive index and Abbe number of the third lens 103 are respectively: Nd=1.80; Vd=44.0; the refractive index and Abbe number of the fourth lens 104 are respectively: Nd=1.44; Vd=96.0; the fourth lens 104 is an extra-low dispersion lens.

[0100] In the second lens group 400, the fifth lens 401 and the sixth lens 402 are cemented to form a second achromatic lens; the refractive index and Abbe number of the fifth lens 401 are respectively: Nd=1.62; Vd=63.4; the refractive index and Abbe number of the sixth lens 402 are respectively: Nd=1.78; Vd=26; the seventh lens 403 and the eighth lens 404 are cemented to form a cemented lens; the refractive index of the seventh lens 403 is: Nd=1.7; the refractive index of the eighth lens 404 is: Nd=1.50.

[0101] See also Figure 6 , Figure 6 This is the MTF diagram of the full-frame aerial photography fixed-focus lens provided in Example 2 of this application at 10lp / mm and 30lp / mm line pairs. The dotted line represents the sagittal direction, and the solid line represents the meridian direction. Figure 2 It can be seen that the MTF of the 0-0.9 field of view lens at 10lp / mm is greater than 0.85, and the MTF of the 0-0.9 field of view lens at 30lp / mm is greater than 0.7, and the imaging is uniform;

[0102] See also Figure 7 , Figure 7 The distortion diagram of the full-frame aerial photography fixed-focus lens provided in Example 2 of the present application is a field of view angle vs distortion diagram corresponding to a wavelength of 546 mm, and the lens distortion is less than 1%;

[0103] See also Figure 8 , Figure 8 This is a relative illumination diagram of the full-frame aerial photography fixed-focus lens provided in Example 2 of the present application. The edge field illumination is >50%, and there is no dark corner.

[0104] Embodiment three:

[0105] The conditional data in this embodiment are shown in Table 5, and the parameters of each lens are shown in Table 6.

[0106] Table 5:

[0107] <![CDATA[F1 / F]]> 0.48 L / F 0.81

[0108] Table 6:

[0109] Surface number Surface type R-Value thickness Refractive Index Abbe number Sur1 Standard 39.19 3.05 1.95 32 Sur2 Standard 101.33 0.14 Sur3 Standard 19.27 4.66 1.50 81 Sur4 Standard 46.45 1.80 Sur5 Standard 39.51 1.30 1.85 32 Sur6 Standard 12.82 5.35 1.44 96 Sur7 Standard 103.00 2.66 STOP Standard infinity 3.08 Sur9 Standard 412.46 1.27 1.49 71 Sur10 Standard 19.84 4.91 Sur11 Standard 23.71 3.21 1.56 68 Sur12 Standard -71.85 1.27 2 25.4 Sur13 Standard 44.89 2.00 Sur14 Standard -90.46 4.04 1.76 27 Sur15 Standard -12.86 1.29 1.58 68 Sur16 Standard -89.27 10.77 Sur17 Standard -15.86 1.30 1.75 52 Sur18 Standard -37.74 0.14 Sur19 Standard 73.45 5.01 1.55 48 Sur20 Standard -49.53 21.76 Image Standard Infinity -

[0110] In this embodiment, the focal length value of the optical system is F=99.4, the aperture coefficient FNO=3.5, and the total optical length L=80.

[0111] The focal length value F1 of the first lens group 100 is 47.72; the optical power of the first lens 101, the second lens 102 and the fourth lens 104 is positive; the optical power of the third lens 103 is negative; the third lens 103 and the fourth lens 104 are cemented together to form a first achromatic lens; the refractive index and Abbe number of the third lens 103 are respectively: Nd=1.85; Vd=32.0; the refractive index and Abbe number of the fourth lens 104 are respectively: Nd=1.44; Vd=96.0; the fourth lens 104 is an extra-low dispersion lens.

[0112] In the second lens group 400, the fifth lens 401 and the sixth lens 402 are cemented to form a second achromatic lens; the refractive index and Abbe number of the fifth lens 401 are respectively: Nd=1.56; Vd=68; the refractive index and Abbe number of the sixth lens 402 are respectively: Nd=2.0; Vd=25.4; the seventh lens 403 and the eighth lens 404 are cemented to form a cemented lens; the refractive index of the seventh lens 403 is: Nd=1.76; the refractive index of the eighth lens 404 is: Nd=1.58.

[0113] See also Fig.10 , Fig.10 This is the MTF diagram of the full-frame aerial photography fixed-focus lens provided in Example 3 of the present application at 10lp / mm and 30lp / mm line pairs. The dotted line represents the sagittal direction, and the solid line represents the meridian direction. From the figure, it can be seen that the MTF of the 0-0.9 field of view lens at 10lp / mm is greater than 0.85, and the MTF of the 0-0.9 field of view lens at 30lp / mm is greater than 0.6, and the imaging is uniform;

[0114] See also Fig.11 , Fig.11 The distortion diagram of the full-frame aerial photography fixed-focus lens provided in Example 3 of the present application is a field of view angle vs distortion diagram corresponding to a wavelength of 546 mm, and the lens distortion is less than 1%;

[0115] See also Fig.12 , Fig.12This is a relative illumination diagram of the full-frame aerial photography fixed-focus lens provided in Example 3 of the present application. The edge field illumination is >50%, and there is no dark corner.

[0116] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A full-frame aerial photography fixed-focus lens, characterized in that: Including the following settings from the object side to the image side: A first lens group, wherein the optical power of the first lens group is positive; An aperture, the aperture of which can be adjusted; A focusing lens, wherein the focusing power of the focusing lens is negative and the focusing lens can move along the optical axis; as well as The second lens group has positive refractive power.

2. The full-frame aerial photography fixed-focus lens according to claim 1, characterized in that: The first lens group includes at least three positive power lenses and at least one negative power lens; Along the direction from the object side to the image side, the first lens in the first lens group is a positive power lens, and a surface close to the object side is a convex surface; the last lens in the first lens group has a concave surface close to the image side.

3. The full-frame aerial photography fixed-focus lens according to claim 2, characterized in that: In the first lens group, at least one negative power lens is glued to one positive power lens to form a first achromatic lens; in the first achromatic lens, the Abbe number and refractive index of the positive power lens and the negative power lens meet the following conditions: Vd1-Vd2>20,Nd2-Nd1>0.2; Among them, Vd1 is the Abbe number of the positive power lens, Vd2 is the Abbe number of the negative power lens, Nd1 is the refractive index of the positive power lens, and Nd2 is the refractive index of the negative power lens.

4. The full-frame aerial photography fixed-focus lens according to claim 2, wherein: In the first lens group, at least one positive power lens is an extra-low dispersion lens.

5. The full-frame aerial photography fixed-focus lens according to claim 1, wherein: The focal length of the first lens group and the focal length of the full-frame aerial photography fixed-focus lens satisfy the following conditional formula: F1 / F≤0.82; Among them, F1 is the focal length value of the first lens group; F is the focal length value of the full-frame aerial photography fixed-focus lens.

6. The full-frame aerial photography fixed-focus lens according to claim 1, wherein: The side of the focusing lens close to the image side is a concave surface; when the object distance increases, the focusing lens moves toward the object side along the optical axis, and when the object distance decreases, the focusing lens moves toward the image side along the optical axis.

7. The full-frame aerial photography fixed-focus lens according to claim 1, wherein: The second lens group includes a plurality of lenses. Along the direction from the object side to the image side, the first lens in the second lens group is a positive power lens, and the second lens is a negative power lens. The first lens and the second lens are glued together to form a second achromatic lens. In the second achromatic lens, the Abbe number and refractive index of the positive power lens and the negative power lens meet the following conditions: Vd1'-Vd2'>20,Nd2'-Nd1'>0.2; Wherein, Vd1' is the Abbe number of the positive power lens, Vd2' is the Abbe number of the negative power lens, Nd1' is the refractive index of the positive power lens, and Nd2' is the refractive index of the negative power lens.

8. The full-frame aerial photography fixed-focus lens according to claim 7, characterized in that: Along the direction from the object side to the image side, the third lens in the second lens group is a negative power lens, the fourth lens is a positive power lens, the third lens and the fourth lens are cemented to form a cemented lens, and in the cemented lens, the Abbe number and the refractive index of the positive power lens and the negative power lens meet the following conditions: Nd3'>Nd4'; Wherein, Nd3' is the refractive index of the positive power lens, and Nd4' is the refractive index of the negative power lens.

9. The full-frame aerial photography fixed-focus lens according to claim 8, characterized in that: Along the direction from the object side to the image side, in the second lens group, the fifth lens is a negative power lens, and a surface of the fifth lens close to the object side is a concave surface, and the sixth lens is a positive power lens.

10. The full-frame aerial photography fixed-focus lens according to any one of claims 1 to 9, characterized in that: The focal length and total optical length of the full-frame aerial photography fixed-focus lens satisfy the following conditional formula: L / F ≥ 0.78; Among them, F is the focal length of the full-frame aerial photography fixed-focus lens, and L is the total optical length of the full-frame aerial photography fixed-focus lens.

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