Movie projector

The first movie projector was the Zoopraxiscope, invented by British photographer Eadweard Muybridge in 1879.

Eadweard Muybridge (9 April 1830 – 8 May 1904, born Edward James Muggeridge) was an English-American photographer important for his pioneering work in photographic studies of motion, and early work in motion-picture projection.

Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras.

The frames are later played back in a movie projector at a specific speed, called the frame rate (number of frames per second).

The first movie projector was the Zoopraxiscope, invented by British photographer Eadweard Muybridge in 1879.

The zoöpraxiscope (initially named zoographiscope and zoogyroscope) is an early device for displaying moving images and is considered an important predecessor of the movie projector.

A movie projector is an opto-mechanical device for displaying motion picture film by projecting it onto a screen.

Traditionally, films were recorded onto celluloid film through a photochemical process and then shown through a movie projector onto a large screen.

A movie projector is an opto-mechanical device for displaying motion picture film by projecting it onto a screen.

Different markets exist for screens targeted for use with digital projectors, movie projectors, overhead projectors and slide projectors, although the basic idea for each of them is very much the same: front projection screens work on diffusely reflecting the light projected on to them, whereas back projection screens work by diffusely transmitting the light through them.

The first commercial, public screening of cinematographic films happened in Paris on 28 December 1895.

The images on the film stock are projected for viewing the motion picture.

By 2006, the advent of much higher 4K resolution digital projection reduced pixel visibility.

In television and consumer media, 38402160 (4K UHD) is the dominant 4K standard, whereas the movie projection industry uses 40962160 (DCI 4K).

In 1999, digital cinema projectors were being tried out in some movie theatres.

Digital movies are projected using a digital video projector instead of a film projector.

In the early 1900s up until the late 1960s, carbon arc lamps were the source of light in almost all theaters in the world.

It continued in use in more specialized applications where a high intensity point light source was needed, such as searchlights and movie projectors until after World War II.

The Xenon arc lamp was introduced in Germany in 1957 and in the US in 1963.

It produces a bright white light that closely mimics natural sunlight, with applications in movie projectors in theaters, in searchlights, and for specialized uses in industry and research to simulate sunlight, often for product testing.

The birth of sound film created a need for a steady playback rate to prevent dialog and music from changing pitch and distracting the audience.

In sound-on-disc technology from the era, a phonograph turntable is connected by a mechanical interlock to a specially modified film projector, allowing for synchronization.

A critical part of understanding these visual perception phenomena is that the eye is not a camera, i.e.: there is no frame rate for the human eye or brain.

To minimize the perceived flicker, projectors employed dual- and triple-blade shutters, so each frame was displayed two or three times, increasing the flicker rate to 48 or 72 Hertz and reducing eye strain.

It is the complete automation of projection that has enabled the modern "multiplex" cinema – a single site typically containing from 8 to 24 theaters with only a few projection and sound technicians, rather than a platoon of projectionists.

The film is projected with a movie projector onto a large projection screen at the front of the auditorium while the dialogue, sounds and music are played through a number of wall-mounted speakers.

70 mm film is also used in both the flat and domed IMAX projection system.

In the 1950s, the potential of 35 mm film to provide wider projected images was explored in the processes of CinemaScope (1953) and VistaVision (1954), following multi-projector systems such as Cinerama (1952).

The intermittent mechanism can be constructed in different ways.

The intermittent mechanism or intermittent movement is the device by which film is regularly advanced and then held in place for a brief duration of time in a movie camera or movie projector.

Sync between the two reels is checked with SMPTE leader, also known as countdown leader.

A film leader is a length of film attached to the head or tail of a film to assist in threading a projector or telecine.

As the reel being shown approaches its end, the projectionist looks for cue marks at the upper-right corner of the picture.

Most projection booths in movie theaters in the past (and in some older theaters and studio screening rooms today) were equipped with two projectors side-by-side to project reels of film alternating between the two projectors.

This technique was first introduced in September, 1953 by Hazard E. Reeves for Cinemascope. Various anamorphic implementations have been marketed under several brand names, including CinemaScope, Panavision and Superscope, with Technirama implementing a slightly different anamorphic technique using vertical expansion to the film rather than horizontal compression.

Its creation in 1953 by Spyros P. Skouras, the president of 20th Century Fox, marked the beginning of the modern anamorphic format in both principal photography and movie projection.

The intermittent movement in these projectors is usually provided by a Geneva drive, also known as the Maltese Cross mechanism.

One application of the Geneva drive is in film movie projectors and movie cameras, where the film is pulled through an exposure gate with periodic starts and stops.

The first form of magnetic sound was the double-head system, in which the movie projector was interlocked with a dubber playing a 35 mm reel of a full-coat, or film completely coated with magnetic iron-oxide.

The sound recording would then be synchronized with a movie projector or a telecine.

In older theaters, there may be manually operated, sliding covers in front of the projection booth's windows.

These include isolating the noise produced by opto-mechanical projectors from the audience, providing appropriate atmospheric control for the projection and film transport equipment (including, in more advanced booths, the use of HEPA air filtration to prevent dust contamination of the film prints in use), the provision of work space for the projectionist to prepare prints for projection and maintain the equipment, and the isolation of dangerous equipment and infrastructure (e.g. potentially explosive xenon bulbs and three-phase power) from untrained members of the public.

Smooth wheels with triangular pins called sprockets engage perforations punched into one or both edges of the film stock.

Sprockets are used in the film transport mechanisms of movie projectors and movie cameras.

Various anamorphic implementations have been marketed under several brand names, including CinemaScope, Panavision and Superscope, with Technirama implementing a slightly different anamorphic technique using vertical expansion to the film rather than horizontal compression.

Panavision was established principally for the manufacture of anamorphic projection lenses to meet the growing demands of theaters showing CinemaScope films.

The way the film is fed from the platter to the projector is not unlike an eight-track audio cartridge.

The endless loop tape concept continued to be used in newer movie projectors, though their tape spool is actively rotated and not drawn by tension on the film.

For techniques used to display pictures with a three-dimensional appearance, see the 3-D film article for some movie history and the stereoscopy article for technical information.

Using left-eye and right-eye prints and two interlocked projectors, left and right frames were alternately projected, each pair being shown three times to suppress flicker.