In the field of photography and videography, the choice of lens mount is crucial to the quality of the image. c-mount and cs-mount, although sounding similar, are in fact distinctly different in their design and use.

Interface Definitions and Uses

C-mount: The C-mount is used primarily for connecting projectors and projection lenses, and in some microscope imaging systems. The diameter of each thread is 1 inch (25 mm), or 32 turns of thread per inch. the distance from the mounting reference plane to the focal plane of a C-mount interface is strictly 17.526 mm. This interface design allows a certain distance to be maintained between the lens and the image sensor for optimal imaging.

CS interface (CS-mount): CS interface, on the other hand, is a type of collar used to increase the distance between the lens and the image sensor. The CS-mount is a type of mount that is used to increase the distance between the lens and the image sensor, which is converted between the mounts by means of a collar to achieve optimal image rendering.The CS-mount was designed to help the lens render sharper images, so the main difference between the CS-mount and the C-mount lies in the distance between the image sensor and the lens. Specifically, the CS interface reduces this distance to 12.5mm, a reduction from the 17.5mm of the C interface.

Distance Differences

C interface: The distance from the image sensor to the lens is 17.5 mm, which is its fixed design standard.

CS interface: The distance from the image sensor to the lens is 12.5 mm. To use a C-interface lens with a CS-interface camera, it is usually necessary to add a 5 mm washer (C/CS connection ring) to enable interface conversion.

Compatibility and Applications

Compatibility: Due to the difference in distance between the C and CS interfaces, they are not fully compatible. However, it is possible to mount a C-interface lens on a CS-interface camera and vice versa by using a conversion ring (C/CS connection ring).

Application Scenarios: The C interface, because of its longer focal length, is more suitable for applications that require a larger working distance, such as microscope imaging, industrial inspection, etc. The CS interface, on the other hand, because of its longer focal length, is more suitable for applications that require a larger working distance. The CS interface, because of its shorter focal length, is more suitable for occasions with higher space requirements, such as small cameras, surveillance cameras, etc..

There is a significant difference between the C and CS interfaces in the distance between the lens and the image sensor, and this difference determines their applicability in different application scenarios.