Definitions for "C-mount"
Keywords:  flange, trinocular, lenses, cctv, focal
A type of camera lens mount that enables different lenses to be swapped out and used on a security camera.
The standard screw mounting for 2/3" and 1" camera lenses. The distance from the flange surface to the focal point is 17.526 mm. A C-mount lens can be used on a camera with a CS-mount by adding an adapter ring to reduce this distance to 12.5 mm.
This is a specific type of camera, as well as its corresponding lens mount. The C-mount lens is found in older versions of security cameras, and has a flange back distance of 17.5mm. In order to achieve a focused image, a 5mm ring must be inserted between the camera and lens.