Projector Central researchers and analysts, during tests with the Dell product, found the S500wi produced a 75-inch diagonal image (63 inches wide) sitting only five inches from the screen.

From just two feet, the projector can create an image measuring 100 inches diagonally, according to Dell.

Dell’s latest ultra short-throw projector, along with many others on the market, don’t require the pesky task of calibrating the on-screen image every time the projector is moved, even by a few inches. This can be particularly useful for educators who move projectors around the classroom on carts.

The S500wi, like others in the extreme short-throw category, can create large images from less than a foot away from the screen by reflecting the image off a mirror.

There are, however, new extreme short-throws that avoid the use of mirrors, which experts say can degrade the on-screen image, if only slightly.

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Mitsubishi’s WD380U-EST and XD380U-EST extreme short-throw projectors don’t rely on mirrors to cast a large image from a short space, but instead employ specialty lenses introduced by the company in May.

The newest Mitsubishi line of ultra short-throws requires more space in front of the screen or wall—about two feet instead of the five inches needed for the Dell projector—but the company claims it provides a clearer image for educators and their students.

“It’s technological prowess that we use to create imaging wonder, not smoke and mirrors,” said Wayne Kozuki, product manager for Mitsubishi Digital Electronics.

Mitsubishi’s latest short-throw machine features a lamp life of up to 6,000 hours if left on “low mode” and a built-in 10-watt speaker, which will work even if the projector is left on standby mode. This would allow professors to save lamp life by shutting down the projector’s visual component without sacrificing audio that could be crucial to a presentation or lecture.

Panasonic’s PT-ST10 is another short-throw projector that needs less than two feet of space to operate. The short-throw projector can be attached to Panasonic’s whiteboard, known as the Panaboard, using an attachment piece stemming from the top of the whiteboard.

Projector Central has a tool that can take the guessing out of projector choices, especially for faculty members unsure which projector to request for their classroom with limited space.

The website’s “Projection Calculator Pro” helps educators understand which machines will fit in the available room space. Using manufacturer-supplied specifics on a range of projectors, Projector Central’s calculator accounts for screen size, room lighting, and—of course—the number of feet a professor has between a projector cart and a screen or wall.

Leading technology companies also have released products made for enhancing short-throw projectors in the classroom.