Gloassary
Arc Lamp – can be xenon or arc, provides light to project the film image on the screen
Aspect Ratio - width to height ratio of the picture on one frame of film
Cue mark - a black dot, usually in the upper-right corner of the frame, located 8 seconds and 1 second from the end of a 20-minute reel of film
Dowser – an asbestos plate before the shutter which blocks the light source when the projector is not in use
Exciter Lamp – an incandescent bulb used in reading optical soundtracks
Flat - a format of film with an aspect ratio of 1.37:1 or 1.85:1
Frame - one picture on a reel of film; there are 24 frames in one second of a movie
Framing Lines - the black bands located between frames on the film
Gates - pads and rollers which can be opened and closed for threading and movie showing
Intermittent Sprocket - a sprocket in the projector located just below the aperture which rotates to allow one frame to be displayed every 24th of a second
Pads - similar to a roller, holds the film down on a sprocket
Platter System - a type of projection which allows an entire movie to be shown on one reel with no changeovers
Rollers - similar to a pad, holds the film down on a sprocket
Scope - a format of film with an aspect ratio of 2.35:1
Shutter – a piece of metal which either allows or prevents light from passing over the aperture