3-D film

A 3-D ("three-dimensional") film or S3D film^[1] is a motion picture that enhances the illusion of depth perception. Derived from stereoscopic photography, a special motion picture camera is used to record the images as seen from two perspectives (or computer-generated imagery generates the two perspectives), and special projection hardware and/or eyewear are used to provide the illusion of depth when viewing the film. 3-D films are not limited to feature film theatrical releases; television broadcasts and direct-to-video films have also incorporated similar methods, primarily for marketing purposes.

3-D films have existed in some form since 1890, but until 2010 had been largely relegated to a niche in the motion picture industry because of the costly hardware and processes required to produce and display a 3-D film, and the lack of a standardized format for all segments of the entertainment business. Nonetheless, 3-D films were prominently featured in the 1950s in American cinema, and later experienced a worldwide resurgence in the 1980s and 90s driven by IMAX high-end theaters and Disney themed-venues. 3-D films became more and more successful throughout 2000-09, culminating in the unprecedented success of 3-D presentations of Avatar in December 2009, followed by the record-breaking opening of Tim Burton's Alice in Wonderland in March 2010.

Stereoscopic motion pictures can be produced through a variety of different methods. Over the years the popularity of various systems being widely employed in movie theaters has waxed and waned. Though anaglyph (see next section) was sometimes used prior to 1948, during the early "Golden Era" of 3-D cinematography of the 1950s the polarization system was used for every single feature length movie in the United states, and all but one short film^[2]. In the 21st century, polarization 3-D systems have continued to dominate the scene, though during the 60s and 70s some classic films which were converted to anaglyph for theaters not equipped for polarization, and were even shown in 3D on TV^[3]. In the years following the 90s, some movies were made with short segments in anaglyph 3D. Following are some of the technical details and methodologies employed in some of the more notable 3-D movie systems that have been developed: