The UV lens is also called Ultra Violet, which is a kind of filter used by exponential code cameras to protect the lens and improve the quality of the picture. UV mirrors are usually colorless and transparent, and some will appear purple or magenta at a certain angle due to the addition of anti-reflection coating. The main function is to absorb ultraviolet rays with a wavelength below 400 nanometers, and it has no filtering effect on other visible/invisible light. The reason it can filter ultraviolet rays is because the lens contains lead, so the UV lens is heavier than other lenses of the same size and thickness. At the same time, the UV mirror can prevent the coating of the lens surface from directly contacting the external environment, which plays a protective role.

The UV lens is suitable for shooting in the seaside, mountains, snowfields and open areas, and can reduce the blue tone caused by ultraviolet rays. At the same time for digital cameras, it can also exclude the interference of ultraviolet rays on the CCD, which helps to improve the clarity and color reproduction effect. Muti-layer coated UV mirrors have a certain improvement in light transmittance compared to ordinary UV mirrors, and are the most common UV mirrors used by film friends.