Production Glossary
Film projector
A film projector, also known as a movie projector, is a mechanism utilized in the display of motion pictures. The projector is broken down into four elemental units- spooling system, lamp, lens, and audio system. The device works as follows:A roll of film is set onto the spool of the projector, which is spun by an electric motor. The spool spins, transferring the film to an empty roll on the second spool. A the transfer occurs, the singular frames are stopped for a split second in front of a projector lamp. As the light shines through the frame of film, and before it shows up on a screen, the image is enlarged by a lens so it will appear larger than the original frame size. In order for the audio and image to match, the audio system will release the sound slightly before the frame it is paired with. This compensates for the travel time of the sound to the ears of the audience.
The common sizes of film projectors are 8 mm (for home use), 16 mm (for educational use), and 35 mm (for motion picture use).
