Gain factor

The gain factor informs you of the luminance of the respective projector screen in comparison to a surface that is standard white-coated. The factor expresses how many times lighter the picture is seen by the viewer. The viewing angle must be taken into consideration, though.

To be able to compare different projector screen's coatings, one has a matt white, rough surface that reflects light equally in all directions given as gain factor 1.0.

Projector screen surfaces that reflect less light to left and right and so achieve a lighter picture for the viewer who is sitting in the middle, have a factor that is higher than 1.0. Such a high factor can only be achieved by "bundling" the light in one direction. Through this bundling, the diffused light of the projection surface is reduced. Through this a lighter depiction of the picture depends very much on the viewing angle.

For use in the cinema viewing at home, the Gain-Factor of 1.2 should not be exceeded. In any case, make sure to ask the manufacturer of the cloth for a diagram confirmation of the Gain-Factor in which is described the dependency factors of the viewing angles.