Distance which is present between the Specimen surface and the detector plane.

Camera length depends on the optical setup and it is ideally determined from calibration measurements using known samples, e.g., gold on carbon.

Historically the term camera length was used in TEM, however more recently there have been innovative applications in SEM, see publications provided under examples provided in this class.

This definition applies to the experimental technique of Fraunhofer far field diffraction. In diffraction mode the quantity camera length is used to qualify the level of magnification of the diffraction pattern onto the detector. Note that the camera length may by altered by the addition of lenses in the beam transforming the physical quantity in a virtual one.