Move the aperture fixed-focus lens. The aperture of this lens can be changed, but the focal length cannot be changed. Suitable for occasions where the focal length is fixed and the illumination brightness changes little; Manual aperture zoom lens, the use method is the same as above, but in some cases, considering the scope and distance of the camera environment, the lens is used if it is uncertain; Automatic aperture fixed focus lens, when the ambient illumination changes, this lens drives the lens aperture motor through the amplitude of the output signal of the camera brightness level, thus automatically adjusting the aperture size and ensuring the illumination falling on the target surface to be constant. Suitable for situations where the illumination changes greatly and the focal length of the camera is fixed. Automatic aperture zoom lens, the application mode is the same as above. In some cases, this lens is used when the scope and distance of the camera environment are not determined; Variable lens. The adjustment of the aperture and focal length of this lens is controlled by electronic control. Generally, this kind of lens has a long focal length and a wide zoom range. The aperture can be controlled and remotely controlled, so it is used in general projects.