Gain refers to the screen's ability to reflect and amplify the brightness of the projected image. It is a measure of how effectively the screen reflects light back to the viewer's eyes. The gain value represents the ratio of the screen's reflective power compared to a standard reference surface, usually a matte white screen with a gain of 1.0.
The gain value indicates the amount of reflective lumens that the screen can provide. A higher gain value means that more light is reflected back, resulting in a brighter image on the screen. Conversely, a lower gain value means less light is reflected, resulting in a dimmer image.
The gain value of a screen also influences the width of the viewing angle. A screen with a higher gain will have a narrower viewing angle, meaning that viewers must be positioned more directly in front of the screen to experience the maximum brightness. On the other hand, a screen with a lower gain will have a wider viewing angle, allowing viewers to see a brighter image even if they are not directly in front of the screen.
It's important to note that the choice of gain depends on the specific viewing environment and the desired viewing experience. Factors such as ambient light, screen size, projector brightness, and audience seating arrangement all play a role in determining the optimal gain for a given situation.