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To present a STEREOSCOPIC MOTION PICTURE, two images are projected superimposed onto the same screen through CIRCULAR POLARIZING FILTERS of opposite handedness. The viewer wears eyeglasses which contain a pair of analyzing filters (circular polarizers mounted in reverse) of opposite handedness. Light that is left-circularly polarized is blocked by the right-handed analyzer, while right-circularly polarized light is blocked by the left-handed analyzer. The result is similar to that of stereoscopic viewing using linearly polarized glasses, except the viewer can tilt his or her head and still maintain left/right separation (although stereoscopic image fusion will be lost due to the mismatch between the eye plane and the original camera plane)
The UNIPOAR 3D SYSTEM for cinemas is a polarized 3D system, that is based on the projector presenting a alternating segments of circularly polarized material. Mounted in front of the projector lens, this filter is synchronized to the projected images, giving each frame a polarization perpendicular to the previous one, which can be viewed with polarized 3D glasses.