Aperture diameter calibration test system and method

Abstract

The aperture aperture calibration and testing system and method provided in this application describe a system where a control module controls an aperture motor via signals. The aperture motor adjusts the aperture mechanism to form the light-transmitting aperture. A camera captures an image of the light-transmitting aperture. The control module processes the image to calculate the actual light-transmitting diameter, and then uses optical formulas to calculate the aperture F-number. This eliminates the need for measurement in imaging instruments or optical test stands, resulting in a small, low-cost system that facilitates rapid deployment and mass production on production lines. The system employs an independent testing architecture, directly driving and testing the aperture mechanism without requiring the assembly of the entire lens, thus improving testing flexibility. The method describes adjusting the aperture aperture with the aperture motor, recording the motor's step count, obtaining the actual light-transmitting diameter through image processing, and calculating the aperture F-number by combining the camera's focal length with the actual light-transmitting diameter, achieving measurement without the need for testing equipment.

Description

Technical Field

[0001] This application relates to the field of optical testing equipment technology, and in particular to an aperture transmission diameter calibration test system and method. Background Technology

[0002] In the design and tuning of camera lenses, the aperture diameter (entrance pupil diameter) is a crucial parameter determining the lens's F-number (aperture number). Different aperture positions correspond to different aperture diameters, and their accuracy directly affects the lens's exposure performance and the consistency of its optical parameters.

[0003] In existing technologies, the measurement of the aperture's light transmission diameter usually relies on testing the entire lens after assembly using imaging instruments or optical stands. However, such testing equipment is bulky and expensive, which is not conducive to large-scale deployment on production lines. Summary of the Invention

[0004] The technical problem to be solved by this application is that in the prior art, the measurement of the aperture diameter usually relies on testing with imaging instruments or optical stands after the entire lens is assembled. However, the testing equipment such as imaging instruments or optical stands is large in size and expensive, which is not conducive to large-scale deployment on the production line.

[0005] To address the aforementioned problems, or at least partially address the aforementioned technical issues, this application provides an aperture transmittance diameter calibration test system and method.

[0006] In a first aspect, the present invention discloses an aperture light transmission diameter calibration and testing system, which includes a control module, a camera, an aperture mechanism, and an aperture motor. The control module is connected to the vision detection module and the aperture motor, and the aperture motor is connected to the aperture mechanism. An aperture motor drives the aperture mechanism to move, and the aperture mechanism forms a corresponding light-transmitting hole. The camera captures the image in the aperture mechanism. The control module obtains the number of steps driven by the aperture motor and the captured aperture image. The control module performs image processing on the aperture image to calculate the actual light-transmitting diameter and the aperture F-number.

[0007] Preferably, the control module includes a main control unit, a visual signal transmission unit, and an aperture driving unit, with the main control unit connected to the visual signal transmission unit and the aperture driving unit respectively; The visual signal transmission unit is connected to the camera, and the aperture drive unit is connected to the aperture motor.

[0008] Preferably, the control module includes a data transmission unit and a transmission interface, wherein the data transmission unit is connected to the main control unit and the data transmission unit is connected to the transmission interface.

[0009] Preferably, the control module includes a power supply unit, which is connected to the data transmission unit and is also connected to the main control unit, the visual signal transmission unit, and the aperture drive unit.

[0010] Preferably, the control module includes a display signal transmission unit, which is connected to the main control unit.

[0011] Preferably, it includes a display screen, which is electrically connected to the display signal transmission unit.

[0012] Preferably, the control module includes a backlight unit, which is connected to the main control unit.

[0013] Preferably, it includes a backlight lamp, which is connected to the backlight unit.

[0014] Secondly, this invention discloses an aperture transmittance diameter calibration test method, applicable to the aforementioned aperture transmittance diameter calibration test system, comprising, Initialize the system, drive the aperture motor to drive the aperture mechanism to adjust the light transmission aperture, and record the number of drive steps of the aperture motor and the theoretical light transmission aperture of the aperture mechanism; The camera captures aperture images under the theoretical light-transmitting aperture in real time. The control module performs image processing on the aperture images and calculates the actual light-transmitting diameter of the aperture mechanism to obtain the actual light-transmitting diameter. Based on the actual light-transmitting diameter and the focal length of the camera, the F-number of the aperture mechanism is calculated to obtain the aperture F-number.

[0015] Preferably, the following steps are then included: A table is created to correspond the number of drive steps of the aperture motor to the actual light transmission diameter, resulting in a light transmission diameter relationship table. The aperture F-number is displayed on the screen, and the relationship table between the aperture F-number and the light transmission diameter is transmitted to the host computer through the data transmission unit.

[0016] The technical solution provided in this application has the following advantages compared with the prior art: The aperture transmittance diameter calibration test system and method provided in this application mention that the control module controls the operation of the aperture motor through signals, the aperture motor adjusts the light-transmitting aperture formed by the aperture mechanism, the camera captures the image in the light-transmitting aperture, the control module performs image processing on the image, calculates the actual transmittance diameter through the image, and then calculates the aperture F number by combining the image with optical formulas. It does not require measurement in testing equipment such as imaging instruments or optical stands. The system is small in size and low in cost, and is easy to deploy and apply in batches on production lines.

[0017] Furthermore, an independent testing architecture is adopted to directly drive and test the aperture mechanism, eliminating the need for assembling the entire lens and improving testing flexibility.

[0018] The method describes adjusting the aperture motor to adjust the light-transmitting aperture, recording the step number of the aperture motor, obtaining the actual light-transmitting diameter through image processing, and calculating the aperture F-number by combining the camera focal length and the actual light-transmitting diameter. This eliminates the need for measurement in imaging instruments or optical test benches, resulting in a small, low-cost system that facilitates rapid deployment and mass application on production lines. Employing an independent testing architecture, it directly drives and tests the aperture mechanism without requiring the assembly of the entire lens, enabling offline testing and calibration of the independent aperture mechanism. This provides flexible testing, unrestricted by the overall machine structure. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A structural module diagram of an aperture transmittance diameter calibration test system provided in this application; Figure 2 A circuit diagram of the main control unit of an aperture transmission diameter calibration and testing system provided in this application; Figure 3 A circuit diagram of the visual signal transmission unit of an aperture aperture diameter calibration test system provided in this application; Figure 4 A circuit diagram of the aperture driving unit of an aperture transmission diameter calibration test system provided in this application; Figure 5 A circuit diagram of the power supply subunit of an aperture aperture diameter calibration test system provided in this application; Figure 6 A circuit diagram of the data transmission unit of an aperture aperture diameter calibration test system provided in this application; Figure 7 A flowchart illustrating the steps of a method for calibrating the aperture diameter provided in this application.

[0022] Explanation of reference numerals in the attached figures: 1. Aperture transmittance diameter calibration and testing system; 11. Camera; 12. Control module; 121. Main control unit; 122. Visual signal transmission unit; 123. Aperture drive unit; 124. Power supply unit; 1241. Power supply subunit; 1242. First voltage regulator subunit; 1243. Second voltage regulator subunit; 125. Data transmission unit; 13. Aperture mechanism; 14. Iris motor; 15. Display screen; 16. Backlighting. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] Firstly, see Figures 1-6 The present invention discloses an aperture light transmission diameter calibration test system 1, which is used for testing and calibrating the light transmission diameter of the aperture.

[0025] The aperture diameter calibration test system 1 includes a control module 12, a camera 11, an aperture mechanism 13, and an aperture motor 14. The control module 12 is connected to the vision inspection module and the aperture motor 14. The aperture motor 14 is connected to the aperture mechanism 13. The control module 12 acquires the image acquired by the camera 11 and calculates the aperture diameter from the acquired image. The aperture mechanism 13 includes aperture blades and its mechanical structure, which are used to form apertures of different sizes. The aperture motor 14 is used to drive the opening and closing of the aperture blades in the aperture mechanism 13.

[0026] Specifically, the aperture motor 14 drives the aperture mechanism 13 to move, forming a corresponding light-transmitting aperture. The camera 11 captures the image from the aperture mechanism 13. The control module 12 obtains the number of steps driven by the aperture motor 14 and the captured aperture image. The control module 12 performs image processing on the aperture image to calculate the actual light-transmitting diameter and the aperture F-number. The control module 12 controls the aperture motor 14 to operate via signals, adjusting the light-transmitting aperture formed by the aperture mechanism 13. The camera 11 captures the image from the light-transmitting aperture. The control module 12 performs image processing on the image, calculates the actual light-transmitting diameter from the image, and then calculates the aperture F-number using optical formulas. This eliminates the need for measurement in imaging instruments or optical test stands, resulting in a small system size, low cost, and easy deployment and mass application on production lines.

[0027] Furthermore, an independent testing architecture is adopted to directly drive and test the aperture mechanism 13, eliminating the need to assemble the entire lens and improving testing flexibility.

[0028] The control module 12 includes a main control unit 121, a visual signal transmission unit 122, and an aperture drive unit 123. The main control unit 121 is connected to the visual signal transmission unit 122 and the aperture drive unit 123 respectively. The visual signal transmission unit 122 is connected to the camera 11, and the aperture drive unit 123 is connected to the aperture motor 14.

[0029] Specifically, the visual signal transmission unit 122 transmits the image captured by the camera 11 to the main control unit 121. The aperture drive unit 123 drives the aperture motor 14 and controls the aperture motor 14 to drive the aperture blades to form a light-transmitting hole through the signal. The main control unit 121 outputs aperture drive control commands and calculates the real-time light-transmitting diameter and aperture F number based on the image data captured by the visual signal transmission unit 122.

[0030] The main control unit 121 includes chip U1, which is an STM32H750VBT6 chip. The aperture drive unit 123 includes chip U3, which is a DRV8833PWPR chip. The visual signal transmission unit 122 includes interface H3, which connects to chip U3 and the aperture motor 14. Pins E7, E8, E9, and E10 of chip U1 are connected to pins E7, E8, E9, and E10 of chip U3. The eighth pin of interface H3 is connected to pin B1 of chip U1. Pin B1 is used for aperture shutter status detection and can cooperate with the visual signal transmission unit 122 to determine the opening or closing state of the aperture in real time and record the corresponding motor steps. Chip U3 is a motor driver chip used to drive the aperture motor 14, achieving precise control of the aperture motor 14.

[0031] As one embodiment, the main control unit 121 has a built-in image processing subunit and a calculation processing subunit. The image processing subunit can perform image processing on the image transmitted by the visual signal transmission unit 122, and the calculation processing subunit calculates the actual light transmission diameter and aperture F number based on the processing results of the image processing subunit.

[0032] The control module 12 includes a data transmission unit 125 and a transmission interface. The data transmission unit 125 is connected to the main control unit 121 and the transmission interface. The transmission interface is connected to an external device to obtain power and data. The host computer transmits data to the main control unit 121 through the transmission interface and the data transmission unit 125.

[0033] Specifically, the data transmission unit 125 is used to obtain power and transmit data. The transmission interface adopts a TYPE-C interface. In the data transmission unit 125, the VBUS terminal transmits power signals, the D+ terminal and the D- terminal transmit data, and transmit data with the USB_N terminal and USB_P terminal of the chip U1.

[0034] The aperture diameter calibration test system 1 includes a display screen 15 and a backlight lamp 16. The display screen 15 is electrically connected to the display signal transmission unit, and the backlight lamp 16 is connected to the backlight unit. The control module 12 includes a display signal transmission unit and a backlight unit. The display signal transmission unit is connected to the main control unit 121, and the backlight unit is connected to the main control unit 121.

[0035] Specifically, the display screen 15 is used to display the aperture diameter and aperture F-number calculated by the main control unit 121, and the backlight 16 is used to assist the camera 11 in obtaining a clear, high-contrast aperture image. The backlight unit is connected to the LED_R terminal, LED_G terminal, LED_B terminal, and E2 terminal in the chip U1, and the display signal transmission unit is connected to the I2C_SDA terminal and I2C_SCL terminal of the chip U1.

[0036] As one embodiment, the aperture transmission diameter calibration test system 1 includes indicator lights, which are used to visually indicate the system's operating status.

[0037] The control module 12 includes a power supply unit 124, which is connected to the data transmission unit 125. The power supply unit 124 is also connected to the main control unit 121, the visual signal transmission unit 122, and the aperture driving unit 123.

[0038] The power supply unit 124 supplies power to various components within the system. The power supply unit 124 includes a power supply subunit 1241, a first voltage regulator subunit 1242, and a second voltage regulator subunit 1243. The power supply subunit 1241 is electrically connected to both the first voltage regulator subunit 1242 and the second voltage regulator subunit 1243. The power supply subunit 1241 supplies power to the LED, aperture motor 14, main control unit 121, and display screen 15. The first voltage regulator subunit 1242 converts 5V power to 2.8V power, and the second voltage regulator subunit 1243 converts 5V power to 1.5V power. The first voltage regulator subunit 1242 and the second voltage regulator subunit 1243 supply power to the camera 11.

[0039] The power supply subunit 1241 includes chip U8, which is model ME3108A33M5G. The first voltage regulator subunit 1242 includes chip U9, which is model ME6206A28XG. The second voltage regulator subunit 1243 includes chip U10, which is model ME6206A15XG.

[0040] Secondly, see Figure 7 This invention discloses a method for calibrating and testing the aperture's light transmission diameter, applicable to the aforementioned aperture light transmission diameter calibration and testing system, comprising: Step S1: Initialize the system, drive the aperture motor to drive the aperture mechanism to adjust the light transmission aperture, and record the number of drive steps of the aperture motor and the theoretical light transmission aperture of the aperture mechanism; Step S2: The camera acquires the aperture image under the theoretical light-transmitting aperture in real time. The control module performs image processing on the aperture image and calculates the actual light-transmitting diameter of the aperture mechanism to obtain the actual light-transmitting diameter. Based on the actual light-transmitting diameter and the focal length of the camera, the F-number of the aperture mechanism is calculated to obtain the aperture F-number.

[0041] Specifically, in step S1, after the system is powered on, it completes initialization operations such as hardware self-test, backlight illumination activation, and communication port configuration to ensure that the system enters a stable and measurable state. The control module drives the aperture motor according to the preset program to adjust the aperture mechanism to the corresponding target light-transmitting aperture position, synchronously records the current motor drive steps, and generates the theoretical light-transmitting aperture data corresponding to the number of steps based on the aperture mechanical parameters. This establishes the initial correspondence between the motor drive steps and the theoretical light-transmitting aperture, realizing precise and controllable adjustment of the aperture opening position, and laying the foundation for the comparison of measured data and theoretical data and error correction.

[0042] Specifically, in step S2, the camera acquires image data of the current aperture aperture in real time under stable backlight conditions. The control module sequentially performs image processing such as grayscale conversion, filtering and noise reduction, edge extraction, and contour fitting on the image to calculate the actual physical light-transmitting diameter of the aperture mechanism. Then, combined with the known focal length parameters of the camera, the aperture F-number is calculated according to the optical formula. The actual light-transmitting diameter is obtained through visual inspection, replacing the theoretical estimate, and the parameter conversion from light-transmitting diameter to aperture F-number is completed, realizing the actual measurement and calibration of the core optical parameters of the aperture. This obtains high-precision, high-reliability actual light-transmitting diameter and aperture F-number, completing the automated measurement and calibration of aperture parameters, improving measurement accuracy and parameter consistency.

[0043] It is understandable that the aperture motor adjusts the light-transmitting aperture, the step number of the aperture motor is recorded, the actual light-transmitting diameter is obtained through image processing, and the aperture F-number is calculated by combining the camera focal length and the actual light-transmitting diameter. This eliminates the need for measurement in imaging instruments or optical test benches, resulting in a small system size, low cost, and easy rapid deployment and mass application on production lines. Employing an independent testing architecture, it directly drives and tests the aperture mechanism without requiring the assembly of the entire lens, enabling independent offline testing and calibration of the aperture mechanism. This provides flexible testing and is not limited by the overall machine structure.

[0044] The following steps are then included: Step S3: Create a corresponding relationship table between the driving steps of the aperture motor and the actual light transmission diameter to obtain the light transmission diameter relationship table. Display the aperture F-number on the display screen, and transmit the relationship table between the aperture F-number and the light transmission diameter to the host computer through the data transmission unit.

[0045] Specifically, the current aperture motor step count is recorded one-to-one with the calculated light-transmitting diameter, forming a table showing the correspondence between motor step count and light-transmitting diameter. Simultaneously, the corresponding F-number can be calculated using an optical formula based on the known lens focal length: F-number = focal length / light-transmitting diameter. The aperture motor step count, image processing, and diameter calculation processes are repeated to complete the detection of all preset aperture motor step counts until a complete calibration data table is generated. That is, the light-transmitting diameter corresponding to all motor step counts in the table is calibrated. After detection, the measurement results are displayed in real-time on the screen or transmitted to a host computer via a data transmission unit and interface for generating calibration files or importing into the production line automation system. In step S3, the data association and solidification of the motor step count, actual light-transmitting diameter, and aperture F-number are completed, automatically establishing the correspondence between motor step count and light-transmitting diameter, improving production consistency, enabling local visualization of measurement results, and uploading the calibration data for storage, analysis, and calibration file generation. This is suitable for laboratory and production line use. Establish a high-precision calibration data table that can be directly used for production and debugging, so that on-site operators can intuitively view the results. At the same time, the data is traceable and reusable, and supports the connection with the production line automation system.

[0046] Step S2 specifically includes the following steps: Step S21: Perform image preprocessing on the aperture image to obtain a preprocessed image. Image preprocessing includes grayscale conversion and filtering for noise reduction. Step S22: Extract the aperture contour from the preprocessed image, fit the aperture contour, and obtain a pixel-level image of the contour. Step S23: Obtain the pixel diameter from the fitted contour pixel-level image, convert it into the actual physical size according to the pixel equivalent coefficient pre-calibrated by the system, and output the aperture light-passing diameter.

[0047] Specifically, the system acquires the original aperture image under the current theoretical aperture in real time using a camera. Image preprocessing, contour extraction and fitting, and pixel diameter conversion are then performed sequentially, and the aperture F-number is calculated based on the focal length. First, the aperture image undergoes grayscale conversion and filtering for noise reduction, resulting in a denoised preprocessed image. Next, the preprocessed image undergoes aperture contour extraction and fitting to obtain a pixel-level contour image. Contour extraction uses threshold segmentation or edge detection methods, while contour fitting uses least-squares circle fitting or ellipse fitting. Then, the pixel diameter is read from the pixel-level image. Based on a pre-calibrated pixel equivalent coefficient (mm / pixel), the pixel diameter in the image is converted to the actual physical size, yielding the actual aperture diameter. The actual aperture diameter is then output. The pixel equivalent coefficient, a calibration parameter in mm / pixel, is pre-calibrated using a standard ruler or standard aperture under the same optical path conditions. Finally, the aperture F-number is calculated based on the actual aperture diameter and the known focal length of the camera. By eliminating image noise and contour errors through machine vision algorithms, image information is transformed into physical dimensions that can be used for optical calibration. This completes the entire process from image acquisition to the actual light transmission diameter and aperture F-number, effectively improving the accuracy and stability of light transmission diameter measurement and obtaining true and reliable physical measurement values ​​and aperture F-numbers, thus providing an accurate basis for subsequent data correlation and calibration.

[0048] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0049] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0054] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Since these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations.

[0055] The above description describes specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A calibration and testing system for aperture transmission diameter, characterized in that, It includes a control module, a camera, an aperture mechanism, and an aperture motor. The control module is connected to the vision detection module and the aperture motor, and the aperture motor is connected to the aperture mechanism. An aperture motor drives the aperture mechanism to move, and the aperture mechanism forms a corresponding light-transmitting hole. The camera captures the image in the aperture mechanism. The control module obtains the number of steps driven by the aperture motor and the captured aperture image. The control module performs image processing on the aperture image to calculate the actual light-transmitting diameter and the aperture F-number.

2. The system according to claim 1, characterized in that, The control module includes a main control unit, a visual signal transmission unit, and an aperture driving unit. The main control unit is connected to the visual signal transmission unit and the aperture driving unit, respectively. The visual signal transmission unit is connected to the camera, and the aperture drive unit is connected to the aperture motor.

3. The system according to claim 1, characterized in that, The control module includes a data transmission unit and a transmission interface. The data transmission unit is connected to the main control unit, and the data transmission unit is connected to the transmission interface.

4. The system according to claim 1, characterized in that, The control module includes a power supply unit, which is connected to the data transmission unit. The power supply unit is also connected to the main control unit, the vision signal transmission unit, and the aperture drive unit.

5. The system according to claim 1, characterized in that, The control module includes a display signal transmission unit, which is connected to the main control unit.

6. The system according to claim 1, characterized in that, It includes a display screen, which is electrically connected to the display signal transmission unit.

7. The system according to claim 1, characterized in that, The control module includes a backlight unit, which is connected to the main control unit.

8. The system according to claim 1, characterized in that, Includes a backlight lamp, which is connected to the backlight unit.

9. A method for calibrating and testing the aperture's light transmission diameter, applicable to the aperture's light transmission diameter calibration and testing system described in any one of claims 1-8, characterized in that, include, Initialize the system, drive the aperture motor to drive the aperture mechanism to adjust the light transmission aperture, and record the number of drive steps of the aperture motor and the theoretical light transmission aperture of the aperture mechanism; The camera captures aperture images under the theoretical light-transmitting aperture in real time. The control module performs image processing on the aperture images and calculates the actual light-transmitting diameter of the aperture mechanism to obtain the actual light-transmitting diameter. Based on the actual light-transmitting diameter and the focal length of the camera, the F-number of the aperture mechanism is calculated to obtain the aperture F-number.

10. The method according to claim 1, characterized in that, The following steps are then included: A table is created to correspond the number of drive steps of the aperture motor to the actual light transmission diameter, resulting in a light transmission diameter relationship table. The aperture F-number is displayed on the screen, and the relationship table between the aperture F-number and the light transmission diameter is transmitted to the host computer through the data transmission unit.

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