3D technology has been around for years, but only recently has it been incorporated into high-definition television via Blu-ray Discs and digital downloads. 3D is based on the theory of stereoscopy, or creating the illusion of depth in an image.
There are three types of 3D technology:
It’s been around for years, and it’s name is almost synonymous with red and blue glasses. There are many old movies in 3D that utilized red and blue glasses. However, movies such as Coraline make use of red and green combination. Most of the glasses are produced out of paper.
Polarized (also known as “Passive”)
This is the 3D technology used when you go to to 3D theaters such as IMAX or theaters which show 3D films such as Avatar, Alice in Wonderland, and Toy Story 3. The fancier glasses (fancier than paper anaglyph glasses at least), restrict the light that enters each lens thereby sending two different images to create a stereographic effect.
Now these glasses are really fancy, and expensive. Active glasses receive two different images from a 3D TV (that runs at double the refresh rate at a minimum of 120 Hz) to each eye by synching to the television via infrared or other synching method. The refresh rate is so fast that the eye does not notice the shuttering of the image. Active 3D technology is current home solution that has become standardized on Blu-ray Discs.