Abstract: A flashing device attachable to a motion picture camera having a body provided with an objective lens aperture and with at least two magazine apertures over one of which may be detachably mounted a film magazine. The camera comprises a driving mechanism inside its body to move the film stored in the magazine and passing it through one magazine aperture over which the magazine is mounted, in front of the lens aperture in order to expose the successive frames of this film to the light of a scene to be recorded. A casing provided with an opening closed by a ground glass is detachably mounted onto the body of the camera over the other magazine aperture with the opening of the casing facing the other magazine aperture. A lamp is mounted inside the casing for directing light onto the ground glass closing the opening of the casing and therefrom through this opening and its facing aperture, onto the film moving through the body of the camera in order to subject the film to a supplemental uniform exposure.