Particularly with the linear polarization schemes popular since the 1950s, the use of linear polarization meant that a level head was required for any sort of comfortable viewing; any effort to tilt the head sideways would result in the polarization failing, ghosting, and both eyes seeing both images. Circular polarization has alleviated this problem, allowing viewers to tilt their heads slightly (although any offset between the eye plane and the original camera plane will still interfere with the perception of depth).Compared to anaglyph images, the use of polarized 3D glasses produces a full-color image that is considerably more comfortable to watch and is not subject to binocular rivalry. However, it requires a significant increase in expense: even the low cost polarized glasses typically cost 50% more than comparable red-cyan filters, and while anaglyph 3-D films can be printed on one line of film, a polarized film was often done with a special set up that uses two projectors. The use of multiple projectors also raises issues with synchronization, and a poorly synchronized film would negate any increased comfort from the use of polarization. This problem was solved by a number of single strip polarized systems which were standard in the 1980s.
Because neutral-gray linear-polarizing filters are easily manufactured, correct color rendition is possible. Circular-polarizing filters often have a slight brownish tint, which may be compensated for during projection.
Until 2011, home 3D television and home 3D computer primarily used active shutter glasses with LCD or plasma displays. TV manufacturers (LG, Vizio) have introduced displays with horizontal polarizing stripes overlaying the screen. The stripes alternate polarization with each line. This permits using relatively inexpensive passive viewing glasses, similar to those for movies. The principal disadvantage is that each polarization can display only half as many scanning lines.
- Generally inexpensive.
- Do not require power.
- Do not require a transmitter to synchronize them with the display.
- Do not suffer from flicker.
- The images for polarized glasses have to share the screen simultaneously, and therefore cannot have full resolution delivered to each eye simultaneously. A full 1080p picture results from image fusion. This disadvantage does not occur on projections where each pixel can contain information for both eyes.
- Associated with the headaches many people attribute to 3D viewing.
- Narrow vertical viewing angles compared to Active shutter 3D