Viewing Angle

Viewing Angle is the maximum angle at which you can view your flat-panel display without the image appearing faded, weak, or distorted and 180° theoretically is the highest. Often, the horizontal viewing angle (sideways) is listed, but sometimes provide viewing angles both horizontally and vertically. For most home theater systems, the horizontal viewing angle is more critical.

Projection screens maximize the light coming from the projector by reflecting more light back to the audience concentrating the viewing angle. They are made using high-tech fabrics, that either focus or diffuse the light shining on them and control how that light is reflected back to the viewer.

A viewer is situated in front of the screen, and when there are many such viewers, the horizontal viewing angle must be large to allow all of the viewers to see a bright image. Also, it is desirable to have a large horizontal viewing angle so that a viewer can be situated at positions other than directly in front of the screen. The screen surface is best used when there is a good control of ambient light and a moderately wide viewing angle is desired.

Technically the measurement of gain at this point is known as Peak Gain at Zero Degrees Viewing Axis. If you move to the side and view the screen at an angle the brightness of the projected image drops. The angle at which the gain reading drops to 50% of the peak value is known as the Half Gain Viewing Angle. A person viewing the screen from this angle will see an image half as bright as the person seated at the center position. Thus brightness falls off more rapidly as you move away from the zero degree viewing axis, and the Half Gain Viewing Angle is relatively narrow.

If the projector is pointing down 20 degree to the center of the screen, and you are looking UP, to the center of the screen, at a 20 degree angle, you have the full bounce, and the screen image is at its brightest. If you are at a different angle, the screen won't be as bright.

High gain projector screens limit the viewing angle. For a screen with a gain of 1 the picture appears high quality out to about 50 degrees from the projector. But at a gain of 1.5 that viewing angle is reduced to about 35 degrees. Over 2 and the viewing angle is down to around 25 degrees, making it much more difficult to layout your room.