From Photo-3d

Basically, projection of 3D images involves:

1. Use of a dual-lens projector, or two single-lens projectors
2. Polarized filters over each projection lens are aligned at right angles
3. Use an aluminum (silver) or lenticular screen, not a white one. A white screen will de-polarize the light projected, destroying the stereo effect. The silver or lenticular screens preserve the polarization of the projected light.
4. Polarized glasses are worn which match the alignment of the projector lens polarizing filters. In most projectors and glasses, the orientations of the polarization is in a V shape. A notable exception are the IMAX and FED projector and glasses, which have the polarization in the vertical and horizontal directions.

[edit] See Also

• dual-lens slide projectors
• Digital Projection