How Do Polarized 3D Glasses Work?

How do Polarized 3D Glasses work?
Stereoscopy is a technique used to create a three-dimensional illusion by narrowing the margin of light that enters the eye using Polarized 3D glasses for the effect. A stereoscopic film actually consists of two images projected at the same time onto the same area through polarizing filters oriented at right angles to each other. All the viewer has to wear is a cheap pair of spectacles which contain a similar filters. The effect is managed due to the fact that light is only passed through each filter when it has been similarly polarized and has blocked the orthogonally polarized light

Polarized light rays bouncing off a cinema screen often get diffused and this de-polarization can be problematic. If an aluminized or silver screen is used, the situation can be resolved. A station using dual head graphic cards, a silver display surface, a few polarizing filters, and properly aligned DLP hardware can be utilized to create a reasonably priced system. (under US$10 000 in 2003) system for displaying stereoscopic 3d data simultaneously to tens of people wearing polarized glasses. Such a system, called a GeoWall, has been used for several years now in the Earth Sciences thanks to the GeoWall Consortium, with several open source and commercial packages available.

When stereo images are to be presented to a single user, it is practical to construct an image combiner, using partially silvered mirrors and two image screens at right angles to one another. One image is seen directly through the angled mirror whilst the other is seen as a reflection. Correctly adjusted glasses are equipped and filters, properly polarized, are attached to the image screens. There is another, similar system that projects on one screen with the topmost image inverted and viewed in a partly reflective horizontal surface and the lower image shown right-side up. Cathode ray technology is most commonly used in conjunction with polarizing techniques.

In 2003 Keigo Iizuka discovered an inexpensive implementation of this principle on laptop computer displays using cellophane sheets

Polarized stereoscopic pictures have been around since 1936, when Edwin H. It was first introduced to motion pictures by Land. Polarizing projection and glasses were most widely used during the early part of the nineteen fifties when they were used to watch three dimensional films in movie theatres. Note that with the use of anaglyph color filter method, only a small amount of the 3D films of that period were known to use the effect. The novel aspect is their use of digital projection and high-tech IMAX 70mm film projectors, with extremely trustworthy mechanical parts. Using varying forms of polarization, a completely new chronicle of 3D animation films are now beginning to reveal themselves to theaters. Polarization doesn't work as well with home presentations, whether broadcast or on DVD. NBC and the Discovery Channel are beginning to show some of the new HD programming, but it can only be watched through anaglyph lenses.