A 3-D TV creates an illusion of an added visual dimension for viewers using specialized glasses or changing their position. Each type of 3-D TV technology is configured to display the capture system the images were recorded on; however, the common requirement for all 3-D TV methods is to change the way light simultaneously enters the left and right eye. The first worldwide 3-D entertainment channel, HIGH TV, launched in April 2011.
Viewing a 3-D image using the anaglyph method requires glasses with a red lens over the left eye and a blue, green or cyan lens over the right eye. The image is created from two photographs that are offset by 2-1/2 inches, the typical center distance between human eyes. The 3-D technique was first developed in the late 1800s and has been used in comic books, movie theaters and home entertainment systems.
The polarized method of 3-D entertainment utilizes two images that are projected at right angles to each other. A set of 3-D glasses filters the image to ensure that each eye only sees what it is intended to see, and the human brain merges these images together to create the illusion of depth.
Active Shutter Method
The active shutter or alternate-frame sequencing method uses media recorded with two cameras and placed into a single strip of film in alternating order. The left and right images alternate at 48 frames-per-second -- versus the typical 24 frames-per-second -- and the 3-D glasses open and close the shutters over the eyes so that the correct image can be seen. This process requires linking the glasses to the hardware playing the image to automatically synchronize the open and close sequence.
The autostereoscopy method displays 3-D images without the use of special glasses by creating depth perception for viewers as they position their heads in different positions. Different images engage each eye, producing a stereo image that may ultimately excite some viewers and make others experience eye strain and headaches. In one technique used to create this 3-D method images recorded from varying angles on different 3-D cameras are combined, so that the viewer changing positions sees a holographic effect.
- Media Development Authority: 3-D TV
- Third Dimension TV: 3-D TV Technology
- 3-D Web: Autostereoscopic LCD displays
- 3-D Forums: Autostereoscopic Displays
- Dashwood Cinema Solutions: A Beginner’s Guide to Shooting Stereoscopic 3-D
- HDTV Magazine: Auto-Stereoscopic 3DTV (3-D Without Glasses) - Display Taiwan 2010 Hinted: “Sooner Than You Think” (Part 1)
- Photo Credit Sean Gallup/Getty Images News/Getty Images