Abstract: In a rolling loop motion picture apparatus, such as a projector or camera, the movie film is pressed against a film supporting surface disposed within a light path. In order to be cleaned, the film supporting surface is moved out of the light path to an inoperative position opposite a sheet of material formed of an inert polyurethane material to which particulate contaminants adhere. The sheet is moved into contact with the film supporting surface, whereby the particulate contaminants adhere to the sheet. Then the sheet is retracted from the film supporting surface, along with the particulate contaminants. The film is guided between fixed and movable guide surfaces. The movable guide surface is spring-biased downwardly against the top edge of the film and is constrained against horizontal movement.