A weak temperature drift full-frame large aperture mirrorless lens

Abstract

The utility model discloses a weak temperature drift full frame big aperture micro single lens, including optical system of lens, optical system is from left to right in turn with first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, diaphragm, seventh lens, eighth lens, ninth lens along the light ray incident light path, wherein, first lens is negative refractive power meniscus lens, second lens is negative refractive power double concave lens, third lens is positive refractive power double convex lens, fourth lens is negative refractiive power meniscus lens, fifth lens is positive refractive power double convex lens, sixth lens is positive refractive power double convex lens, seventh lens is negative refractive power meniscus lens, eighth lens is negative refractive power meniscus lens, ninth lens is positive refractive power double convex lens.

Description

Technical Field

[0001] This utility model belongs to the field of optical imaging technology, specifically relating to a full-frame large-aperture mirrorless lens with low temperature drift. Background Technology

[0002] Mirrorless cameras, by eliminating the mechanical reflex mirror structure of DSLRs, offer advantages such as a short flange distance (typically <20mm) and a large mount diameter, enabling more compact bodies and superior imaging angles. However, this also places higher demands on the lenses used. Fast autofocus requires the high-speed autofocus system of mirrorless cameras, but existing internal focusing solutions are prone to significant focus breathing (angle of view >3%), causing image shift in video recordings, and making it difficult to balance focusing speed and image quality. Mirrorless lenses often need to operate in extreme temperature environments: outdoor photography may face temperatures as low as -30°C (e.g., polar regions, high-altitude scenes), while industrial inspection scenarios may encounter temperatures as high as 70°C (e.g., metallurgical, photovoltaic production lines). Existing lenses, due to the thermo-optical effect of lens elements (refractive index drift with temperature) and the mismatch between the lens barrel and the thermal expansion coefficients of the lens elements, are prone to focus plane shift and severe image quality degradation.

[0003] Therefore, a full-frame mirrorless lens that combines "large aperture, no heat generation, fast focusing, and high resolution" with a compact structure is needed. Utility Model Content

[0004] To address the aforementioned issues, this invention proposes a full-frame, large-aperture mirrorless lens with low temperature drift.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A full-frame, large-aperture mirrorless lens with low temperature drift includes an optical system comprising, from left to right, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, an aperture stop, a seventh lens, an eighth lens, and a ninth lens; wherein, The first lens is a negative refractive power meniscus lens, with a convex object side and a concave image side; The second lens is a negative refractive power biconcave lens, with both the object-side and image-side surfaces being concave. The third lens is a positive refractive power biconvex lens, with the object-side surface being convex and the image-side surface being convex. The fourth lens is a negative refractive power meniscus lens, with a concave object side and a convex image side; The fifth lens is a positive refractive power biconvex lens, with the object-side surface being convex and the image-side surface being convex. The sixth lens is a positive refractive power biconvex lens, with a convex object side and a convex image side; The seventh lens is a negative refractive power meniscus lens, with a concave object side and a convex image side; The eighth lens is a negative refractive power meniscus lens, with a concave object side and a convex image side; The ninth lens is a positive refractive power biconvex lens, with both the object-side and image-side surfaces being convex.

[0006] Furthermore, the air gap between the first lens and the second lens is 19.2-21.2 mm; the air gap between the second lens and the first cemented lens composed of the third and fourth lenses is 2.8-3.2 mm; the air gap between the first cemented lens and the fifth lens is 13.2-15.1 mm; the air gap between the fifth lens and the second cemented lens composed of the sixth and seventh lenses is 5.1-6.3 mm; the air gap between the second cemented lens and the eighth lens is 4.2-5.3 mm; and the air gap between the eighth lens and the ninth lens is 0.2-0.3 mm.

[0007] Furthermore, the radii of curvature of the front and rear surfaces of each lens satisfy the following range: The radii of curvature of the front and rear surfaces of the first lens are 74.2~78.2 mm and 17.2~25.2 mm, respectively. The radii of curvature of the front and rear surfaces of the second lens are -34.5 to -38.2 mm and 28.2 to 31.5 mm, respectively. The radii of curvature of the front and rear surfaces of the third lens are 70.2~75.2mm and -20.2~-25.5mm, respectively. The radii of curvature of the front and rear surfaces of the fourth lens are -20.2 to -25.5 mm and -90.2 to -95.2 mm, respectively. The radii of curvature of the front and rear surfaces of the fifth lens are 17.2~21.2mm and -97.2~-102mm, respectively. The radii of curvature of the front and rear surfaces of the sixth lens are 63.2~66.2mm and -12.3~-15.2mm, respectively. The radii of curvature of the front and rear surfaces of the seventh lens are -12.3 to -15.2 mm and 521.9 to -533.2 mm, respectively. The radii of curvature of the front and rear surfaces of the eighth lens are -7.2 to -9.2 mm and -10.2 to -11.9 mm, respectively. The radii of curvature of the front and rear surfaces of the ninth lens are 230.2~-235mm and -24.2~-26.9mm, respectively.

[0008] Furthermore, the optical system includes aspherical surfaces, and the surface shape of each aspherical surface satisfies the following formula: , Where z is the distance vector from the vertex of the aspherical surface along the optical axis at a height of x; x is the radial distance from the center of the lens; c is the curvature of the aspherical surface, and c = 1 / R, where R is the radius of curvature of the aspherical surface; k is the conic coefficient; and A, B, C, D, E, and F are the aspherical coefficients.

[0009] Furthermore, the parameters of the aspherical surface satisfy the following requirements: The aspheric coefficients of the front surface of the first lens are: A = 5.479, B = -4.808 × 10⁻⁶. -8 C = 2.313 × 10 -5 D = 9.272 × 10 -11 E = -8.414 × 10 -14 F = -8.414 × 10 -14 ; The aspheric coefficients of the rear surface of the first lens are: A = 0.389, B = -2.454 × 10⁻⁶. -5 C = 1.002 × 10 -8 D = -4.848 × 10 -10 E = 1.839 × 10 -12 F = -2.552 × 10 -12 ; The aspherical coefficients of the front surface of the eighth lens are: A = -1.740, B = 9.376 × 10⁻⁶. -6 C = 3.138 × 10 -6 D = -4.010 × 10 -8 E = 1.835 × 10 -10 F = -2.797 × 10 -12 ; The aspheric coefficients of the rear surface of the eighth lens are: A = -2.439, B = 5.791 × 10⁻⁶. -5 C = 2.498 × 10 -6 D = -2.584 × 10 -8 E = 1.072 × 10 -10 F = -1.670 × 10 -13 .

[0010] Furthermore, the light rays pass through the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, aperture stop, seventh lens, eighth lens, and ninth lens in sequence from left to right to form an image.

[0011] After adopting the above technical solution, the present invention has the following beneficial effects: 1. This utility model discloses a full-frame, large-aperture mirrorless lens with low temperature drift. The lens's optical system comprises nine lenses arranged sequentially from left to right along the incident light path. Each lens has specific refractive power and surface characteristics. The front and rear surfaces of the first and eighth lenses are aspherical, effectively correcting higher-order aberrations. Some lenses form a cemented lens group to compensate for spherical and chromatic aberration. Simultaneously, "thermal following" technology is used to correlate lens parameters over a wide temperature range, reducing the impact of temperature changes on imaging. The lens also strictly controls the air gap and radius of curvature between the lenses to ensure imaging performance.

[0012] 2. This utility model discloses a full-frame mirrorless camera lens with low temperature drift (no thermalization from -30℃ to 70℃), weak focus breathing effect, large aperture (F≤2.0), and high resolution (MTF≥0.6 at 40lp / mm). It also has a compact structure (total length≤110mm) and is suitable for full-frame mirrorless cameras. It can meet the application needs of professional photography, video creation, industrial inspection and other scenarios in low light, wide temperature outdoor and high-precision vision tasks. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the optical structure of this utility model; Figure 2 This is a distortion image of the low-temperature drift full-frame large-aperture mirrorless lens of this invention at -30℃. Figure 3 The distortion image of the low-temperature drift full-frame large-aperture mirrorless lens of this utility model at 20℃; Figure 4 The distortion image of the low-temperature drift full-frame large-aperture mirrorless lens of this utility model at 70℃; Figure 5 This is a schematic diagram of the MTF curve of the weak temperature drift full-frame large aperture mirrorless lens of this utility model at -30℃ with a spatial frequency of 40lp / mm. Figure 6 This is a schematic diagram of the MTF curve of the weak temperature drift full-frame large aperture mirrorless lens of this utility model at 20℃ with a spatial frequency of 40lp / mm. Figure 7 This is a schematic diagram of the MTF curve of the weak temperature drift full-frame large aperture mirrorless lens of this utility model at 70℃ with a spatial frequency of 40lp / mm.

[0014] The reference numerals in the figure are as follows: L1, First lens; L2, Second lens; L3, Third lens; L4, Fourth lens; L5, Fifth lens; L6, Sixth lens; L7, Seventh lens; L8, Eighth lens; L9, Ninth lens; 1, Lens hood; 2, Pressure ring 1; 3, Spacer 1; 4, Front group lens barrel; 5, Spacer 2; 6, Lens adapter sleeve; 7, Screw hole; 8, Aperture stop; 9, Pressure ring 2; 10, Rear group lens barrel; 11, Fixed guide pin; 12, Sliding guide pin; 13, Focusing ring leather; 14, Spacer 3; 15, Spacer 4; 16, Cam focusing cylinder; 17, Pressure ring 3; 18, Bayonet. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0016] like Figures 1 to 7 As shown, a full-frame, large-aperture mirrorless lens with low temperature drift includes an optical system. The optical system, arranged sequentially from left to right along the incident light path, comprises a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, an aperture stop, a seventh lens L7, an eighth lens L8, and a ninth lens L9. The first lens L1 is a negative refractive power meniscus lens, with a convex object side and a concave image side; The second lens L2 is a negative refractive power biconcave lens, with both the object-side and image-side surfaces being concave. The third lens L3 is a positive refractive power biconvex lens, with a convex object-side surface and a convex image-side surface; The fourth lens L4 is a negative refractive power meniscus lens with a concave object side and a convex image side. The fifth lens L5 is a positive refractive power biconvex lens, with a convex object-side surface and a convex image-side surface; The sixth lens L6 is a positive refractive power biconvex lens, with a convex object side and a convex image side; The seventh lens L7 is a negative refractive power meniscus lens with a concave object side and a convex image side. The eighth lens L8 is a negative refractive power meniscus lens with a concave object side and a convex image side. The ninth lens L9 is a positive refractive power biconvex lens, with both the object-side and image-side surfaces being convex.

[0017] The air gap between the first lens L1 and the second lens L2 is 19.2-21.2 mm; the air gap between the second lens L2 and the first cemented lens composed of the third lens L3 and the fourth lens L4 is 2.8-3.2 mm; the air gap between the first cemented lens and the fifth lens L5 is 13.2-15.1 mm; the air gap between the fifth lens L5 and the second cemented lens composed of the sixth lens L6 and the seventh lens L7 is 5.1-6.3 mm; the air gap between the second cemented lens and the eighth lens L8 is 4.2-5.3 mm; and the air gap between the eighth lens L8 and the ninth lens L9 is 0.2-0.3 mm.

[0018] The radii of curvature of the front and rear surfaces of each lens satisfy the following range: The radii of curvature of the front and rear surfaces of the first lens L1 are 74.2~78.2mm and 17.2~25.2mm, respectively; The radii of curvature of the front and rear surfaces of the second lens L2 are -34.5~-38.2mm and 28.2~31.5mm, respectively. The radii of curvature of the front and rear surfaces of the third lens L3 are 70.2~75.2mm and -20.2~-25.5mm, respectively. The radii of curvature of the front and rear surfaces of the fourth lens L4 are -20.2 to -25.5 mm and -90.2 to -95.2 mm, respectively. The radii of curvature of the front and rear surfaces of the fifth lens L5 are 17.2~21.2mm and -97.2~-102mm, respectively. The radii of curvature of the front and rear surfaces of the sixth lens L6 are 63.2~66.2mm and -12.3~-15.2mm, respectively. The radii of curvature of the front and rear surfaces of the seventh lens L7 are -12.3 to -15.2 mm and 521.9 to -533.2 mm, respectively. The radii of curvature of the front and rear surfaces of the eighth lens L8 are -7.2 to -9.2 mm and -10.2 to -11.9 mm, respectively. The radii of curvature of the front and rear surfaces of the ninth lens L9 are 230.2~-235mm and -24.2~-26.9mm, respectively.

[0019] The optical system includes aspherical surfaces, and the surface profiles of each aspherical surface satisfy the following formula: , Where z is the distance vector from the vertex of the aspherical surface along the optical axis at a height of x; x is the radial distance from the center of the lens; c is the curvature of the aspherical surface, and c = 1 / R, where R is the radius of curvature of the aspherical surface; k is the conic coefficient; and A, B, C, D, E, and F are the aspherical coefficients.

[0020] The parameters of the aspherical surface must meet the following requirements: The aspheric coefficients of the front surface of the first lens L1 are: A = 5.479, B = -4.808 × 10⁻⁶. -8 C = 2.313 × 10 -5 D = 9.272 × 10 -11 E = -8.414 × 10 -14 F = -8.414 × 10 -14 ; The aspheric coefficients of the rear surface of the first lens L1 are: A = 0.389, B = -2.454 × 10⁻⁶. -5 C = 1.002 × 10 -8 D = -4.848 × 10 -10 E = 1.839 × 10 -12 F = -2.552 × 10 -12 ; The aspherical coefficients of the front surface of the eighth lens L8 are: A = -1.740, B = 9.376 × 10⁻⁶. -6 C = 3.138 × 10 -6 D = -4.010 × 10 -8 E = 1.835 × 10 -10 F = -2.797 × 10 -12 ; The aspherical coefficients of the rear surface of the eighth lens L8 are: A = -2.439, B = 5.791 × 10⁻⁶. -5 C = 2.498 × 10 -6 D = -2.584 × 10 -8 E = 1.072 × 10 -10 F = -1.670 × 10 -13 .

[0021] The light rays pass through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the aperture stop, the seventh lens L7, the eighth lens L8, and the ninth lens L9 from left to right to form an image.

[0022] In this embodiment, the following lenses are arranged coaxially from left to right along the optical axis: first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8, and ninth lens L9. The specific parameters of each lens are as follows: The first lens L1 is an even-order aspherical negative lens with an even-order aspherical surface on both the object and image sides. It has a thickness of 5.00 mm and is made of low-dispersion glass with a refractive index n≥1.5 and an Abbe number v≥55. The characteristics of this material can effectively reduce chromatic aberration and improve the color reproduction of the image. The second lens L2 is a standard negative lens with a spherical object side and an image side. It has a thickness of 2.00 mm and is made of H-QF14 material, which has high refractive index and low dispersion characteristics. The refractive index n≥1.6 and the Abbe number v≤40 are used together with the first lens L1 to further optimize the chromatic aberration correction effect. The third lens L3 is a standard positive lens with a spherical object side and an image side. It has a thickness of 9.50 mm and is made of high-refractive-index glass with a refractive index n≥1.8 and an Abbe number v≤40. It enhances the light-gathering ability and improves image clarity. The fourth lens L4 is a standard negative lens with a spherical object side and an image side. It has a thickness of 1.70 mm and is made of high-refractive-index glass with a refractive index n≥1.9 and an Abbe number v≤40. It forms a cemented lens group with the third lens L3. By utilizing the difference in refractive index between the two lens materials, it effectively compensates for spherical aberration and chromatic aberration. The fifth lens, L5, is a standard positive lens with a spherical object side and an image side. It has a thickness of 5.78 mm, is made of low-dispersion glass, has a refractive index n≥1.5, and an Abbe number v≥55. It further optimizes the chromatic aberration of the system and improves light transmittance. The sixth lens, L6, is a standard positive lens with a spherical object-side surface and an image-side surface. It has a thickness of 6.70 mm, is made of low-dispersion glass, has a refractive index n≥1.5, and an Abbe number v≥55, which enhances the system's ability to control light and improves imaging resolution. The seventh lens L7 is a standard negative lens with a spherical object side and an image side. It has a thickness of 4.20 mm and is made of high-refractive-index, low-dispersion glass with a refractive index n≥1.6 and an Abbe number v≤40. It forms a cemented lens group with the sixth lens L6 to compensate for field curvature and distortion of the system and improve the imaging quality of the edge field of view. The eighth lens, L8, is an even-order aspherical negative lens. The object side and the image side are both even-order aspherical. The thickness is 2.0 mm. The material is glass with a special coefficient of thermal expansion, refractive index n≥1.8, and Abbe number v≥40. It can effectively correct the residual aberrations of the system and reduce the impact of temperature changes on imaging. The ninth lens, L9, is a standard positive lens with a spherical object side and an image side. It has a thickness of 8.224 mm and is made of high-transmittance, low-dispersion glass with a refractive index n≥1.8 and an Abbe number v≥40. This lens enhances the system's imaging brightness and color reproduction while ensuring the flatness of the image surface.

[0023] In this embodiment, to achieve a compact structural design, the total length of the lens is less than 110mm, which facilitates the expansion of the portability of the mirrorless camera, while meeting the requirements of full-frame imaging, and the half-image height reaches 21.675mm.

[0024] In this embodiment, the aspherical surface shape of the optical system also satisfies the aspherical formula described above, and the conic coefficients and higher-order aspherical coefficients of each aspherical surface are shown in Table 1: Table 1: Conic coefficients and higher-order aspheric coefficients of various aspherical surfaces Front surface (*S1) of the first lens (L1) 5.479 <![CDATA[2.313×10 -5 ]]> <![CDATA[-4.808×10 -8 ]]> <![CDATA[9.272×10 -11 ]]> <![CDATA[-8.414×10 -14 ]]> <![CDATA[-8.414×10 -14 ]]> Rear surface of the first lens (L1) (*S2) 0.389 <![CDATA[2.454×10 -5 ]]> <![CDATA[1.002×10 -8 ]]> <![CDATA[-4.848×10 -10 ]]> <![CDATA[1.839×10 -12 ]]> <![CDATA[-2.552×10 -12 ]]> Front surface (*S14) of the eighth lens (L8) -1.740 <![CDATA[9.376×10 -6 ]]> <![CDATA[3.138×10 -6 ]]> <![CDATA[-4.010×10 -8 ]]> <![CDATA[1.835×10 -10 ]]> <![CDATA[-2.797×10 -12 ]]> Rear surface of the eighth lens (L8) (*S15) -2.439 <![CDATA[5.791×10 -5 ]]> <![CDATA[2.498×10 -6 ]]> <![CDATA[-2.584×10 -8 ]]> <![CDATA[1.072×10 -10 ]]> <![CDATA[-1.670×10 -13 ]]> Through the precise design of the aspherical parameters described above, the optical system in this embodiment can effectively eliminate various aberrations such as spherical aberration, coma, distortion, and field curvature, ensuring imaging quality across the entire field of view.

[0025] To verify the focusing performance of the lens in this embodiment, parameters were tested under different focusing conditions, and the specific data are shown in Table 2: Table 2: System Focusing Data Table As shown in Table 2, the lens in this embodiment exhibits minimal focal length variation at infinity and the closest focusing distance (250mm), and smooth image height variation during focusing. This indicates a weak focus breathing effect, which can effectively reduce image shift during video shooting and meet the needs of professional video creation.

[0026] To evaluate the temperature adaptability of the lens in this embodiment, its imaging performance was tested under different temperature environments. The specific results are as follows: Distortion Test: The lens distortion was measured using professional optical testing equipment at temperatures of -30℃, 20℃, and 70℃. The test results are as follows: Figure 2 , 3 As shown in Figure 4, within the temperature range of -30℃ to 70℃, the maximum distortion of the lens is less than 0.8%, the degree of distortion is small and stable with temperature changes, indicating that it has good temperature adaptability and can maintain excellent imaging distortion control capability in extreme temperature environments; Modulation Transfer Function (MTF) Test: The modulation transfer function is an important indicator for evaluating the imaging quality of an optical system. The closer the MTF value is to 1, the higher the imaging resolution of the system. The MTF value of the lens at a spatial frequency of 40 lp / mm was tested at temperatures of -30℃, 20℃, and 70℃. The test results are as follows: Figure 5 , 6As shown in Figure 7, within the temperature range of -30℃ to 70℃, at a spatial frequency of 40 lp / mm, the MTF is greater than 0.60 within a 0.8 field of view, indicating that the lens has high imaging resolution under different temperature conditions and can meet the requirements of full-frame high-quality imaging.

[0027] In addition, the lens in this embodiment also has the following performance advantages: Wide applicable wavelength range: It can cover the 0.486~0.656μm wavelength range, which includes the main range of visible light, and can meet the color reproduction needs of various scenarios such as daily photography and professional creation; Large aperture: F / #2.0. The large aperture design increases the amount of light entering the lens, enabling clear and bright images to be captured even in low-light conditions. It also achieves a shallow depth of field effect, highlighting the subject. Small incident angle: CRA (chief ray angle) ≤18°. A smaller chief ray incident angle can reduce the loss of light due to reflection and refraction on the sensor surface, and improve the brightness uniformity and color accuracy of the image.

[0028] In summary, the low-temperature drift full-frame large-aperture mirrorless lens in this embodiment achieves performance advantages such as low temperature drift, low focus breathing effect, large aperture, and high resolution through reasonable lens combination, precise optical parameter design, and the application of "thermal follow" technology. At the same time, it has a compact structural design, is suitable for full-frame mirrorless cameras, and can meet the application needs of various scenarios such as professional photography, video creation, and industrial inspection.

[0029] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A full-frame, large-aperture mirrorless lens with low temperature drift, characterized in that: An optical system including a lens, wherein the optical system comprises, from left to right along the incident light path, a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), an aperture stop, a seventh lens (L7), an eighth lens (L8), and a ninth lens (L9); wherein, The first lens (L1) is a negative refractive power meniscus lens, with a convex object side and a concave image side; The second lens (L2) is a negative refractive power biconcave lens, with both the object-side and image-side surfaces being concave. The third lens (L3) is a positive refractive power biconvex lens, with both the object-side and image-side surfaces being convex. The fourth lens (L4) is a negative refractive power meniscus lens with a concave object side and a convex image side. The fifth lens (L5) is a positive refractive power biconvex lens, with the object side and the image side being convex. The sixth lens (L6) is a positive refractive power biconvex lens with a convex object side and a convex image side; The seventh lens (L7) is a negative refractive power meniscus lens with a concave object side and a convex image side. The eighth lens (L8) is a negative refractive power meniscus lens with a concave object side and a convex image side. The ninth lens (L9) is a positive refractive power biconvex lens, with both the object-side and image-side surfaces being convex.

2. The full-frame large-aperture mirrorless lens with low temperature drift as described in claim 1, characterized in that: The air gap between the first lens (L1) and the second lens (L2) is 19.2-21.2 mm; the air gap between the second lens (L2) and the first cemented lens composed of the third lens (L3) and the fourth lens (L4) is 2.8-3.2 mm; the air gap between the first cemented lens and the fifth lens (L5) is 13.2-15.1 mm; the air gap between the fifth lens (L5) and the second cemented lens composed of the sixth lens (L6) and the seventh lens (L7) is 5.1-6.3 mm; the air gap between the second cemented lens and the eighth lens (L8) is 4.2-5.3 mm; and the air gap between the eighth lens (L8) and the ninth lens (L9) is 0.2-0.3 mm.

3. The full-frame large-aperture mirrorless lens with low temperature drift as described in claim 1, characterized in that, The radii of curvature of the front and rear surfaces of each lens satisfy the following range: The radii of curvature of the front and rear surfaces of the first lens (L1) are 74.2~78.2 mm and 17.2~25.2 mm, respectively; The radii of curvature of the front and rear surfaces of the second lens (L2) are -34.5~-38.2mm and 28.2~31.5mm, respectively; The radii of curvature of the front and rear surfaces of the third lens (L3) are 70.2~75.2mm and -20.2~-25.5mm, respectively. The radii of curvature of the front and rear surfaces of the fourth lens (L4) are -20.2 to -25.5 mm and -90.2 to -95.2 mm, respectively. The radii of curvature of the front and rear surfaces of the fifth lens (L5) are 17.2~21.2mm and -97.2~-102mm, respectively. The radii of curvature of the front and rear surfaces of the sixth lens (L6) are 63.2~66.2mm and -12.3~-15.2mm, respectively. The radii of curvature of the front and rear surfaces of the seventh lens (L7) are -12.3 to -15.2 mm and 521.9 to -533.2 mm, respectively. The radii of curvature of the front and rear surfaces of the eighth lens (L8) are -7.2 to -9.2 mm and -10.2 to -11.9 mm, respectively. The radii of curvature of the front and rear surfaces of the ninth lens (L9) are 230.2~-235mm and -24.2~-26.9mm, respectively.

4. The full-frame large-aperture mirrorless lens with low temperature drift as described in claim 1, characterized in that, The optical system includes aspherical surfaces, and the surface profiles of each aspherical surface satisfy the following formula: ， Where z is the distance vector from the vertex of the aspherical surface along the optical axis at a height of x; x is the radial distance from the center of the lens; c is the curvature of the aspherical surface, and c = 1 / R, where R is the radius of curvature of the aspherical surface; k is the conic coefficient; and A, B, C, D, E, and F are the aspherical coefficients.

5. A full-frame, large-aperture mirrorless lens with low temperature drift as described in claim 4, characterized in that, The parameters of the aspherical surface must meet the following requirements: The aspherical coefficients of the front surface of the first lens (L1) are: A = 5.479, B = -4.808 × 10⁻⁶. -8 C = 2.313 × 10 -5 D = 9.272 × 10 -11 E = -8.414 × 10 -14 F = -8.414 × 10 -14 ; The aspheric coefficients of the rear surface of the first lens (L1) are: A = 0.389, B = -2.454 × 10⁻⁶. -5 C = 1.002 × 10 -8 D = -4.848 × 10 -10 E = 1.839 × 10 -12 F = -2.552 × 10 -12 ; The aspherical coefficients of the front surface of the eighth lens (L8) are: A = -1.740, B = 9.376 × 10⁻⁶. -6 C = 3.138 × 10 -6 D = -4.010 × 10 -8 E = 1.835 × 10 -10 F = -2.797 × 10 -12 ; The aspherical coefficients of the rear surface of the eighth lens (L8) are: A = -2.439, B = 5.791 × 10⁻⁶. -5 C = 2.498 × 10 -6 D = -2.584 × 10 -8 E = 1.072 × 10 -10 F = -1.670 × 10 -13 .

6. The full-frame large-aperture mirrorless lens with low temperature drift as described in claim 1, characterized in that: The light rays pass through the first lens (L1), the second lens (L2), the third lens (L3), the fourth lens (L4), the fifth lens (L5), the sixth lens (L6), the aperture stop, the seventh lens (L7), the eighth lens (L8), and the ninth lens (L9) from left to right to form an image.

Images