Is the projection screen gain as high as possible?

If we want to understand the performance of the projection curtain, we must first understand the following parameters. We usually use gain to describe the reflective ability of a curtain. Project light onto a fully diffuse surface and set the reflected brightness to 1. Then, under the same conditions, the same light is projected vertically onto the curtain, and the brightness of the midpoint and the points on the same arc is measured. The ratio of this brightness to the brightness of the completely diffuse reflection is called the gain of the curtain. Project the same light onto a screen with a different gain, and the higher the gain, the more brightness we see on the screen.

Semi-gain is also an important measure of screen brightness. We know that when we look vertically on the screen, the brightness at the center of the screen should be highest, but when we look off-center, the brightness drops. The gain when the brightness of the screen is half of the bright point is called the half gain, and the viewing Angle is called the half gain Angle. Half-gain Angle is an important indicator of how good the screen is. The larger the half-gain Angle, the greater the viewing Angle we have on the screen and the more clearly we can see.

A screen with a smaller gain looks more peaceful, but is more affected by ambient light. A high-gain screen is brighter, has more layers, behaves better in color, and is less affected by ambient light. Does that mean the bigger the screen, the better? The answer is no. In fact, there is an inverse relationship between the gain and the viewing Angle on the screen. When the gain is high, the brightness of the middle points will be high but the brightness of the four corners will be low, and the brightness of the picture will be more concentrated. So it's not that the higher the gain, the better the picture.