Ultra Short Throw (UST) projectors provide a solution for small spaces where there isn’t room for the projector to a typical distance from the screen, and in presentation areas where light in the eyes would be an issue. UST projectors are located less than 2 feet from the screen, making it easier to avoid obstructions.
UST projectors were first introduced in 2003, when NEC brought the WT600 to market, and Draper has several viewing surface solutions that are perfect for UST projection. Our screens were among the first tested with UST projectors, so we know what it takes to provide the best experience with UST projection. If you’re thinking about UST projection, here are some things to keep in mind:
The most important thing when choosing a screen for a UST project is that the surface needs to be a “full diffusor.” That means the light from extreme angles is diffused to the viewer. Viewing surfaces that have higher amounts of specular reflection, such as higher performing ambient light rejecting screens, will reflect some of the projector light away from the viewer and should not be used.
A “hot spot” is an area of the screen that is much brighter than the rest of the screen. It will look like a ball of light on the screen. This is a reflection of light from the projector lens, and can be a real problem since UST projectors are so close to the viewing surface. To avoid hotspotting, stay away from using high gain viewing surfaces with UST projectors. Use a surface with a gain of 1.0 or lower to avoid hotspotting.
The Flatter the Better
Flatness is even more important than usual with UST projection. Because the projector is so close to the screen, even the smallest waves or wrinkles can create greater distortion because the angle is much wider. In addition, the lenses on the smaller UST projectors don’t have the best focus uniformity (one corner versus the opposite), and they don’t always have perfect geometry. Because of this, we recommend using only tab-tension electric or fixed frame screens with UST projectors.
Screen surface uniformity is also more important with UST projection. The projector’s proximity to the viewing surface makes it easy to see differences in performance from one part of the screen to another. We recommend premium surfaces designed for maximum uniformity.
For the best results with front projection, we recommend TecVision XT1000X White and TecVision XH700X Grey. These diffusive surfaces offer no or negative gain to avoid hotspotting and offer uniform performance throughout the entire screen surface.
We have also created a solution specifically for ultra- short throw projection under ambient light. TecVision XH800X UST ALR delivers improved contrast and color saturation in moderate to high ambient light applications. This surface can reject 57% of off axis ambient light, while still being able to support extremely wide viewing angles.
For details on these and other projection solutions, click here to compare our flexible viewing surfaces.
Terry Coffey - Draper Inc.