1. The imaging scale of the lens should be consistent with the CCD target scale of the industrial endoscope camera. As mentioned above, there are 1 inch, 2 / 3 inch, 1 / 2 inch, 1 / 3 inch, 1 / 4 inch, 1 / 5 inch and other standards.
2. The inherent principle of lens resolution to describe the imaging quality of lens is the optical transfer function and distortion of lens. However, for support, what we need to know is only the spatial resolution of lens. Taking the number of black and white stripes that can be resolved per millimeter as the measurement unit, the calculation formula is: lens resolution n = 180 / height of frame pattern. Because the size of CCD target surface of industrial endoscope camera has been standardized, for example, the target surface of 1 / 2-inch camera is 6.4mm wide and 4.8mm high, and that of 1 / 3-inch camera is 4.8mm wide and 3.6mm high. Therefore, for 1 / 2 INCH CCD target, the resolution of the lens should be 38 pairs of lines / mm. For 1 / 3 inch camera, the resolution of the lens should be more than 50 pairs of lines. The smaller the target of the camera, the higher the resolution of the lens.
3. Firstly, the focal length of the lens is selected according to the distance from the industrial endoscope camera to the monitored target. After the focal length f is determined, the visual field is determined by the target plane of the camera.
4. Aperture or luminous flux the luminous flux of a lens is measured by the ratio of the focal length of the lens to the luminous aperture. Marked by F, each lens is marked with its larger f value. The luminous flux is inversely proportional to the square of the F value. The smaller the F value is, the larger the aperture is. So we should choose the manual aperture or the active aperture lens according to the light change degree of the monitored part.