C mount is a screw mount that fixes the camera and lens by screws.
Inner diameter 25.4 mm (1 inch), screw pitch 0.794 mm, flange back 17.526 mm is C mount standard
With the miniaturization camera, there is also a CS mount that reduces C flange back by 5 mm.
(The caliber and screw pitch are the same.)
Depending on the camera, 5 mm thick rings may be installed to both C mount and CS mount, so that It’s necessary they can be removed.
Summary
Both C mount and CS mount can be mounted with the same aperture and screw pitch.
However, please take a note that the performance of the lens can not be fully demonstrated.
(The symptoms such as ” out of focus”, “the focal length fluctuates even though it is a zoom lens (* 1)”, “the magnification changes”, etc.)
(* 1) Please refer to “Macro lens and macro zoom lens”.