Tech Talk: Up Close
Sep 1, 2008 12:00 PM, By C. William Day
Short-throw projectors are an impressive new technology tool.
Over the last several years, short-throw projectors have been popping up in many education institutions. These video or data projectors can be positioned unusually close to the projection surface, minimizing installation constraints and maximizing presentation applications.
Imagine being able to get a bright, vibrant, 80-inch diagonal image from a projector placed only a few inches from the screen. Think about not having to worry about blocking the projector light path and casting huge shadows on a presentation, and never having to squint against the glare of the lamp. The short-throw projector makes it possible.
Short-throw and ultra-short-throw projectors are the “in” technology tool for educators. Much of their appeal comes from the ability to use them with interactive whiteboards.
Short-throw projectors can display large images while only inches away from the screen. In fact, when the projector is placed flush with the screen's surface — in other words, a throw distance of zero inches — it displays a 70-inch diagonal 4:3 image. From 3 inches away, the image is nearly 80 inches diagonal.
These new projectors deliver more than 2,000 ANSI lumens in their brightest mode. Short-throw projectors now on the market give enough lumen power that ambient light should not be an issue unless the sun is shining directly on the screen.
One of the problems in education facilities is how to get a big image in a small room. A variety of just-on-the-market short-throw projectors perform well in classrooms, conference rooms and auditoriums where the space is limited to a stage area, or locations where the one-and-a-half times the width of the screen mounting distance is not possible. The best benefit of using a short-throw projector is that it reduces shadows more than standard projectors when used with an interactive whiteboard. These projectors come with automatic keystone correction, networking connectivity and a remote.
Ultra-short-throw projectors, which are mirror-based, don't look like a standard multimedia projector. The lens has been designed to produce big-screen presentations from a short distance (typically 3 to 19 inches) between projector and screen. Short-throw projectors enable a user to have more space during a classroom presentation and eliminate shadow effects caused by people and objects in front of the screen. To produce this size image on a standard business projector, it would have to be at least 6 to 10 feet away from the screen.
Now for the bad news: progress comes with a price. You can expect to pay more for the short-throw because it has a specialized lens. But if you have a small room or want to be closer to the audience, short-throw projectors may be a worthwhile investment.
Day is senior analyst at KBD Planning Group, Young Harris, Ga., a firm specialized in educational facilities and technology planning. He can be reached at bday@kbdplanning.com. www.kbdplanning.com
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