Gain (projection screens)

Gain is a property of a projection screen and is one of the specifications quoted by projection screen manufacturers.

Interpretation

The measured number is called the peak gain at zero degrees viewing axis. It represents the gain value for a viewer seated along a line perpendicular to the screen's viewing surface. The gain value represents the screen's brightness ratio relative to a set standard. Screens with a higher brightness than this standard are rated with a gain higher than 1.0, while screens with lower brightness are rated from 0.0 to 1.0. Since a projection screen is designed to scatter the impinging light back to the viewers, the scattering can be highly diffuse or highly concentrated. Highly concentrated scatter results in a higher screen gain at the cost of a more limited viewing angle, whereas highly diffuse scattering results in lower screen gain with the benefit of a wider viewing angle.