Film: Lens which collects and directs light through both gate and lens.1 A simple lens system that concentrates light in a beam. Used in printing machines.


Audio: A type of microphone which uses the movement of a diaphragm between two charged plates to produce an electrical output.


Historical name for capacitor.



1 Case, D., 1985, Motion Picture Film Processing, Media Manuals, Focal Press, London, Boston