Screen gain

The luminance factor is used to evaluate the dispersion characteristics ( reflection behavior ) picture walls. It is defined from the ratio of the luminance of a sample for screen luminance of a perfectly diffusing and reflecting surface. Such a surface is referred to as the white standard.

The luminance factor can always be specified for only one viewing direction. In order to characterize the reflective properties of a projection screen, so you need a table of luminance factors depending to a certain viewing direction. Graphically illustrates one such assignment in the form of a so-called luminance factor indicatrix.

A luminance factor of 1.5 means that a particular screen in a certain direction 1.5 times more reflective than a standard white surface. The light is amplified in this direction, so to speak.

In many German data sheets for projection video walls of the luminance factor is also referred to as " gain factor ". In the English language the term "Screen Gain" is in use.