Projection booth

A projection booth (US English), projection box (British English) or bio box (Australian English) is a room or enclosure for the machinery required for the display of movies on a reflective screen, located high on the back wall of the presentation space. It is common in a movie theater.

History

During the early cinema period (1895 to the late 1900s approximately), the projector was typically located and operated within the theatre auditorium itself. The move to physically segregated projection booths resulted from the emergence of auditoria specifically designed for the projection of movies, which was caused by a combination of the growing popularity of cinema and increasing concerns over the safety risks of nitrate film. Projection booths that were segregated and equipped with fire prevention, fighting and containment infrastructure gradually became a legal requirement throughout the developed world.

A typical example of the regulation that emerged during this period was the fire safety provisions of the Cinematograph Act 1909 in the United Kingdom.

To maintain isolation between projection room and auditorium, windows were fitted in the projection room wall through which the image is projected and are usually made from a special, high grade glass designed to minimise distortion and light loss through absorption and reflection. They are often called portholes, as they were usually much smaller than the windows typically found in buildings. The origin of the reduced size dates back to the ability to manufacture glass without imperfections that could distort the image but more importantly these openings to the auditorium had to be made fireproof. Steel guillotine shutters were fixed over each window between projection room and the auditorium and in case of fire a low melting point fuse would release the shutters and isolate the projection room from the auditorium should the glass break from the heat of a fire.