How to Choose a Screen for a Front-Projection System
Choosing a screen for a front-projection display system isn't for the faint of heart. The projection screen is what you shine the image on, and they come in all shapes, sizes, and price ranges. Each type of screen has its own advantages and drawbacks.
Find out what screens your projector manufacturer recommends, ask your dealer what he or she recommends, and if at all possible, look at your projector (or the identical model) on the screen before you buy. The three major manufacturers of screens for front-projection displays are Da-Lite, Draper, and Stewart Filmscreen.
Types of projector screens
Screens come in several different forms:
Fixed wall- and ceiling-mounted screens: If you have a dedicated home theater and you’ll never want to hide the screen, these are probably the best way to go.
Retractable screens: These can be manually or electrically powered. Although nothing is cooler than pressing a button on the remote and having the screen come down, this setup will cost you more than the manual version. You also need to make sure that these systems are properly installed so that they are flat (otherwise the image can be distorted), and periodically check to make sure they haven’t become misaligned with use.
Portable screens that sit on a tripod: You can fold these up and put them away when you’re done. These are less than optimal, and generally not recommended for a home theater. If you take them down, you need to get them back in exactly the same spot or refocus the projector.
The technical characteristics of the screen are also important. Keep in mind the following:
Gain: Gain is a measure of how reflective the screen is — how much of the projector’s light gets bounced back to your eyeballs. There’s a standard industry reference for gain, and systems that have exactly as much gain as that reference are rated at a gain of 1. More-reflective (high-gain) screens are rated greater than 1 (say 1.2), while less-reflective (low-gain) screens are rated below 1 (many are rated at 0.8).
Generally speaking, match CRT projectors with high-gain screens (between 1 and 1.3, though you can go higher if needed). Brighter, fixed-pixel systems such as LCD or DLP can use a low-gain screen (0.8 or lower).
Viewing angle: Most display systems have a limited angle (from perpendicular) in which they look best. Sit outside that angle, and the picture becomes dim. For front-projector screens, this viewing angle is inversely proportional to gain. In other words, the higher the gain, the smaller the angle in which viewers will get a good picture. For this reason, you are best off choosing the lowest gain screen that works with your projector in your room.
This is why low-gain screens are recommended for fixed-pixel projectors; LCD, DLP, and LCoS projectors have light to spare, so why not trade some of it for a wider viewing angle? Viewing angles are usually listed in a number of degrees (such as 90). Your viewing angle is half this amount (45, in this case) on either side of perpendicular.
Hotspotting: One reason you shouldn’t use a screen with too high a gain for your projector is the hotspotting phenomenon. When this occurs, one part of the screen is brighter than the other parts. Typically, the center of the screen gets too bright relative to the edges, which makes the picture on the edges appear washed out.
Aspect ratio: Screens are available in either the 16:9 widescreen or 4:3 aspect ratio. You should choose the same aspect ratio as that of your projector. You can buy (or make your own, if you’re crafty) masks to cover the unlit portions of the screen when you’re watching material of a different aspect ratio.