C-Mount is the industry standard attachment for digital imaging devices that are dedicated to microscopes. Choosing the appropriate adapter for your camera and microscope has an enormous impact on the quality of the image and the size of the field of view that you will be able to capture. Different relay lens values are appropriate to different camera sensor sizes and will dramatically affect the camera's field of view.

C-Mount is a 1" diameter threaded port with a specific focal depth to the camera sensor. The port is female on the camera side and male on the microscope attachment. A C-Mount adapter is often necessary to attach a dedicated digital microscope camera to the trinocular output of a microscope, which is often a 23mm smooth-wall trinocular tube (DIN standard) or sometimes a proprietary mount that is unique to the optics of a particular microscope. Many C-Mount adapters will include some type of adjustment to assist in bringing the camera and the primary ocular view into par-focus with one another.