Screens Critical to Corporate AV
Jul 13, 2006 8:00 AM, By John McKeon
“A high gain screen can make a low-lumen projector look better,” says Kevin Baisley, vice president of sales and marketing at Vutec Corporation. That’s just one tip to illustrate how big a contribution corporate AV users and their integrators can realize from a system component that’s often an afterthought at best: the projection screen.
At the recent Projection Summit in Orlando, Fla., several speakers noted that although projector manufacturers routinely tout the brightness and contrast ratios of their machines, these numbers don’t tell the whole story—indeed, they can be downright misleading without some consideration of the screen on which an image is being presented.
Helping corporate customers evaluate factors like these and develop effective systems that meet their needs is going to be the key role of AV integrators in the future, as products like displays become more widely available at commodity prices, says Insight Media’s Chris Chinnock. “The challenge of the corporate AV integrator is to convince the corporate buyer that ‘hang & bang’ is not so easy,” Chinnock says.
Screen considerations are a prime example. At the Summit, Jacob Christensen of DNP Denmark pointed out that some of the huge contrast ratios being promoted by projector vendors aren’t really relevant in daily use. For effective viewing, he noted, an onscreen image should be no more than three times brighter than the white paper on the user’s desk, and not more than 10 times brighter than the darkest part of the room. The risk, if these levels are exceeded, is eye fatigue that will greatly hamper the communications process.
The choice of a screen also depends in large part on the ambient light conditions in which the projected image must be viewed. Corporate boardrooms are special in this regard because conferees generally want to be able to take notes and read documents, which precludes any significant darkening of the room.
That’s where screen gain can come in. Gain is the degree to which a screen reflects an image back to the eye that’s actually brighter than what was projected on the screen. Standard white matte screens command a majority of the market, Baisley says, but some other materials can deliver five or six times as much gain. As a result, the user may be able to achieve a brighter onscreen image without buying a much brighter projector.
Screen manufacturers are also delivering a growing array of motorized screen options, as well as screens in different shapes, including some that are custom designed for specific creative concepts.
It’s also important to specify a large enough screen. Baisley cites the industry’s “rule of seven” as a guide. This rule holds that the distance from the screen to the farthest spectator should not be more than seven times the screen diagonal. In a corporate conference room where the most distant participant is 30ft. or 35ft. away, this rule suggests a minimum screen diagonal of 4ft. or 5ft.
Screen selection and sizing, of course, are prime areas in which volume retail outlets don’t often serve the needs of the corporate user. For advice on these topics, and on linking all elements of a room’s AV systems together in an easy to use configuration, Chinnock notes the integrator must play a critical role.