A stereoscopic 3D display technology that separates the stereo frames by polarization. Using polarizer overlays, the movie projector or TV screen emits the left frame in a different polarization than the right frame, and the viewer wears polarized glasses to filter the frames to the appropriate eyes.
Polarized 3D is also called "passive 3D," because the glasses have no built-in electronics and do not perform any processing (contrast with active 3D
). See 3D visualization
, anaglyph 3D
, lenticular 3D
, parallax 3D
and 3D glasses
Linear and Circular Polarization
Dating back to the 1950s, the linear polarized method was the first 3D technology used for major motion pictures such as the 1953 horror film "House of Wax." The theater projector emitted stereo frames polarized 90 degrees apart. Later on, the technology changed to a clockwise/counterclockwise orientation like the RealD method widely used today. Polarized 3D glasses with two different lens polarizations filter the images to each eye respectively.
The circular polarized method migrated to TVs that alternate the lines of resolution: one line polarized to the left eye, the next line to the right. However, because the lines are interlaced, the viewer sees half the resolution (only 540 lines reach each eye on a 1080p TV). With 2160p 3D TVs, the full 1080p resolution can be delivered (see 4K TV
Polarized 3D for the Cinema
The 3D movie projectors send polarized images to the screen, which reflect back to the viewer's polarized glasses. The circular method is used in today's 3D movies. (Images courtesy of Actif Polarizers Ltd.)
Polarized 3D for Computers and TVs
Linear polarization is adequate for video games, because gamers look straight at the screen. However, people move around more watching TV, and the circular polarization works best.
Polarized RealD Glasses
The RealD glasses (top) are handed out in the movie theater, while the steampunk goggles also have RealD lenses for the retro lover (see RealD glasses
). (Images courtesy of RealD and WillRockwell, www.etsy.com/shop/WillRockwell)