Overhead Projectors
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Selecting the Right Screen
* Pick the type of screen that best suits your particular needs. Front projection screens come in portable, wall, and ceiling mounted models, and in manual or electric (a motor lowers and raises the screen) versions. You might also be interested in a rear projection screen.
* Determine the optimum screen size based on room dimensions, planned audience seating size and arrangement. The rule of thumb is to fit the screen to the audience, and not to the projector. Da-Lite suggests following this formula to determine the appropriate screen size:
** The screen height should be approximately equal to 1/6 the distance from the screen to the last row of seats. Ideally, the first row of seats should be approximately two screen heights away.
** The bottom of the screen should be a minimum of 4 feet above the audience floor, allowing those seated at the rear to see the screen. This may require additional screen "drop" for ceiling hung screens.
* Select the appropriate format for your projection application. Common formats are shown below. More information concerning height and width can be obtained from the retailer and are often specific to the screen.
* "Gain," a measure of the reflectivity of light on the material, is also important to consider. You'll need a higher gain in a lighter environment to better see the image (a lighter room isn't good for projecting an image in general!), but be careful: a too high gain has a mirror-like property and may be distracting. At high levels, viewers will see a blurred image of the projector lens reflected off the screen, a "hot spot." In most cases (unless the room is long and narrow), you should aim for a surface with a gain falling between 1:1 and 1:5.
Screen Surfaces
Screens come in all shapes, types and sizes. Here are some things to keep in mind when choosing:
Front Projection Screen Surfaces
* A large screen will usually have less luminance (quality and amount of light reflected from the surface) than a smaller screen, and therefore less contrast in a lit room. Don't let this discourage you from purchasing a large screen however, just work to make the surrounding room as dark as possible to fix the problem.
* Both white and gray screens are available. White gray screens have higher gain levels, they have less contrast than the traditional white matte screen (which emits more light). For this reason, white screens are more desirable in lighter surroundings (rooms with lighter walls, furniture, and ambient light that you cannot block out, maybe from a window without adequate blinds, etc.).
* Glass beaded screens, with reflective beads embedded in the surface, have greater gain than some other screens. These kinds of screens cannot usually be cleaned in the traditional way (water, mild soap, and a light cloth) however.
* Some screens are manufactured to allow the center channel speaker to be placed directly behind the screen, without loss of audio quality or range.
* Consider a portable or pullmounted one, if you're looking for more space!
Rear Projection Screen Surfaces
* The image is projected onto the screen from behind.
* These kinds of screens usually offer a bright, sharp image and high contrast.
Maintenance
Projector screens are usually flame retardant and mildew resistant. Most can also be washed with a light cloth, mild soap and water.
Manufacturers
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Draper
Other Guides
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Overhead Projectors
