Polarized 3D system
To present a stereoscopic motion picture, two images are projected superimposed onto the same screen through orthogonal polarizing filters (Usually at 45 and 135 degrees).
To present a stereoscopic motion picture, two images are projected superimposed onto the same screen through circular polarizing filters of opposite handedness.
The viewer wears eyeglasses which contain a pair of analyzing filters (circular polarizers mounted in reverse) of opposite handedness.
This means that a pair of aligned DLP projectors, some polarizing filters, a silver screen, and a computer with a dual-head graphics card can be used to form a relatively high-cost (over US$10,000 in 2010) system for displaying stereoscopic 3D data simultaneously to a group of people wearing polarized glasses.
This is a very cost-effective way to convert a theater for 3-D as all that is needed are the attachments and a non-depolarizing screen surface, rather than a conversion to digital 3-D projection.
Polarizing techniques are easier to apply with cathode-ray tube (CRT) technology than with Liquid crystal display (LCD).
In 2003 Keigo Iizuka discovered an inexpensive implementation of this principle on laptop computer displays using cellophane sheets.
[6] One can construct a low-cost polarized projection system by using a computer with two projectors and an aluminium foil screen.
Packs of thin glass sheets, angled so as to reflect away light of the unwanted polarity, served as the viewing filters.
[8] They were first used to show a 3-D movie to the general public at "Polaroid on Parade", a New York Museum of Science and Industry exhibit that opened in December 1936.
At the 1939 New York World's Fair, a short polarized 3-D film was shown at the Chrysler Motors pavilion and seen by thousands of visitors daily.
[12] Cardboard glasses with earpieces and larger filters were used to watch Bwana Devil, the feature-length color 3-D film that premiered on 26 November 1952 and ignited the brief but intense 3-D fad of the 1950s.
Cardboard and plastic frames continued to co-exist during the following decades, with one or the other favored by a particular film distributor or theater or for a particular release.
Some showings of Andy Warhol's Frankenstein during its 1974 U.S. first run featured unusual glasses consisting of two stiff plastic polarizers held together by two thin silver plastic tubes slit lengthwise, one attached across the tops and bent at the temples to form earpieces, the other a short length bent in the middle and serving as the bridge piece.
The design managed to be both stylish in an appropriately Warholesque way and self-evidently simple to manufacture from the raw sheet and tube stock.
At IBC 2011 in Amsterdam RAI several companies, including Sony, Panasonic, JVC & others highlighted their upcoming 3D stereoscopic product portfolios for both the professional and consumer markets to use the same polarization technique as RealD 3D Cinema uses for stereoscopy.
TV manufacturers (LG, Vizio) have introduced displays with horizontal polarizing stripes overlaying the screen.
