What's Your Angle?
Demystifying Screen Viewing Angles

By Jennifer Andrews

Projector screens help images look brighter, crisper and cleaner than walls, chalkboards or other surfaces. In fact, in years past, screens were created that actually made projectors appear brighter by using an especially reflective surface material; however, this reflective fabric created “fall-off” when viewers sat at wider viewing angles from the center of the screen.

Newer screens have reduced the effect of falloff, and brighter projectors have made reflective screens less popular. Let’s take a look at today’s screen surfaces and how viewing angles might be affecting those seated at the outside edges of your congregation.

To understand screens, there are two vital specifications: gain and viewing angle.

Gain is a measurement usually made perpendicular to screen center, of the luminance (brightness) reflected by the screen, divided by the luminance radiating from the projector. Higher-gain screens actually increase the appearance of brightness while lower gain screens don’t.

Lower-gain screens do, however, provide a more consistent brightness throughout the image and from wider viewing angles. Lower-gain screens also reduce glare from ambient light, and improve the contrast ratio, which is desirable for deep, rich black and crisp white images. That’s why low-gain screens are preferred for home-theater applications.

Viewing angle is the angle from a specified viewing position to the center of the screen. It’s usually measured on the horizontal or vertical axis.

Screen manufacturer Da-Lite specifies the viewing angle as the optimum screen brightness from screen center to either side. Lower-gain screens typically have wider viewing angles than higher-gain screens as light is more evenly reflected off the surface.

Those who’ve shopped for a screen in the past have probably heard of glass-beaded screen fabric. Glass-beaded surfaces were helpful in creating brighter-looking images; however, there was fall-off at the sides of the image, which meant those sitting at a wider angle to the screen saw images that weren’t as bright as those closer to the center of the screen. Glass-beaded screens were also more delicate, requiring special care so as to prevent the reflective beads from falling off of the screen. Glassbeaded surfaces are still available from some screen manufacturers, but new high-gain screens are also on the market offering wider viewing angles. As an added bonus, they can be cleaned with a simple soap-and-water solution.

Projector screens today suffer from less fall-off, partly because brighter projectors have reduced the need for high-gain material. The popular Da-Lite Matte White fabric specifies a 50-degree viewing angle, which is its measure from the center of the screen; essentially, this means the screen’s “sweet spot” is 100 degrees. The screen will still be visible outside of that 100-degree angle, but it won’t be nearly as bright as it is within the specified range.

Just a few years ago, a projector was considered “ultra-bright” if it was 1,000 lumens or better today a whereas a 1,000-lumen projector would fall in the lower range of brightness today. The increase in brightness has relieved some of the necessity for higher-gain screens. Therefore, viewing angles have broadened and are less of an issue than in previous years.

Jennifer Andrews is the Internet communications manager for ProjectorPeople.com, where she has been writing tutorials on projection technology for five years. Visit www.projectorpeople.com for more information about this dynamic display technology.