Abstract: To check movement of film in still, or motion picture cameras, a movement sensing means is coupled to the film, for example a cam-operated switch coupled to the film payout spindle, an opto-electrical sensor sensing perforations in the film or the like, and generating film motion pulses. The pulses are counted in an evaluation circuit enabled when film movement is commanded, the evaluation circuit providing an alarm output if a predetermined number of output pulses has not been attained. When related to a motion picture camera, a timing circuit is included to check the generation of the number of pulses within a predetermined timing interval.