Abstract: A device on a film projector for copying movie films in combination with a movie camera which is equipped with a releaser for the exposure of single frames. Said device includes a speed-changing mechanism at the film projector for changing the speed of projection to less than the maximum exposure rate of the movie camera when operating the single-frame releaser. The film projector further comprises a pulse-generating switch, which is operated synchronously with the film feed mechanism of the film projector, such that a pulse is generated or transmitted at each change of frame of the projected film. Said pulses are used for releasing the single-frame releaser of the movie camera.