Oxberry optical printer, M2A.

An optical printer is a device consisting of one or more film projectors mechanically linked to a film camera. It allows filmmakers to re-photograph one or more strips of film. With special lenses for resizing and distorting the material with projectors sending the film image to the camera, fade-outs and fade-ins, dissolves, slow motion, fast motion and image overlays can be easily achieved. More complicated work can involve dozens of elements, all combined into a single scene.