[On the relationship between projection screen gain and viewing angle, distance and brightness] Engineering projection screen

1. The relationship between gain and viewing angle Generally speaking, the gain and viewing angle of the projection screen are a pair of contradictions. Under certain conditions, the higher the gain, the smaller the viewing angle. Conversely, the larger the viewing angle, the lower the gain. Therefore, increasing the viewing angle when the gain is constant or increasing the gain when the viewing angle is constant is a problem that the projection screen Ru0026D experts continue to research, experiment, and need to solve. The Ru0026D experts of Metron metal soft screens are constantly adjusting the formula of the metal reflective coating and the production process of the screen base, trying to increase the viewing angle without reducing the brightness gain. At present, the maximum viewing angle of Metra's metal soft screen has reached 110°. But people have found that when viewed from 40°, the image has begun to deform; when viewed from 80°, the image has been deformed to be meaningless. 2. The relationship between distance and brightness (illuminance×areau003dbrightness) The closer to the light source, the brighter it is, and the farther it is, the darker it is. This is a basic common sense that everyone knows. Similarly, in the field of projection display, the same projector and the same screen have different brightness from different screens on the same screen. In other words, the same projector and screen must be filled with screens of different sizes, and the brightness of the screen will be different because of the distance. But the same projector and picture on screens with different gains are completely different. Experts test: use the same brand, the same model, the same factory time of the projector and the same test screen to hit a normal screen with a gain of 2 and a Metron metal soft screen with a gain of 4. The brightness of the two screens is different due to different gains. Completely different, the screen brightness with high gain is also high.

Test products

Metro Metal Soft Screen

Ordinary glass bead screen

Gain (G)

4

2

Illumination (E)

235.5

235.5

Distance (m)

2.5

2.5

Screen size (in)

72

72

Brightness (B)

300

150

Experts continue to test: move the projector that hits the METRO's metal screen back and away from the screen. When the brightness of the two screens is the same, it is found that the distance between the two projectors is almost doubled, and the projected picture The area hit on the screen is four times different. That is to say: the brightness of the same projector and picture on a 72-inch screen with a gain of 2 is almost equal to the brightness of a 150-inch Metron soft metal screen with a gain of 4.

Test products

Gain (G)

Illumination (E)

Distance (m)

Screen size (in)

Brightness (B)

Meichuang Metal Soft Screen

4

109

5.4

150

138.85

Ordinary glass bead screen

2

235.5

2.5

72

150

But the 150-inch screen can hold the audience and its large picture is by no means comparable to the 72-inch screen. At the same time, the larger the screen size, the greater the number of viewers who can watch the undistorted picture.

72’’’ Projector 150’’ Projector

Three, conclusion

1) In view of the current mainstream projectors whose brightness is above 1500 lumens, when selecting the screen, the small size should consider the large viewing angle, and the large size should consider the high gain.

2) When the illuminance (lumens) of the projector and the brightness of the screen (the desired picture effect) are fixed, a high-gain and large-size screen should be selected as much as possible, so that it is more economical and more in line with the pursuit of the projector . And blindly pursuing a big angle of view has no meaning except to appreciate distorted images.