It may be due to stains or dust on the surface of the lens, which affects the refraction of light; It is also possible that there is displacement or damage to the internal lenses of the lens, which changes the optical structure.

The stability of the detector\'s output signal and its position within the normal dynamic range can be observed. Alternatively, a standard light source can be used for testing to compare the output results with theoretical values.

It will lead to an increase in light energy loss in the optical system, a decrease in imaging brightness, a decrease in contrast, and affect the clarity and quality of the image.