Rear Projection: The method of transmitting light through the surface of the

substrate. Light sources can be from a projector, traditional

lighting fixture (ellipsoidal's, fresnel's, parcan's) or from intel-

ligent moving lights. The light source is on the opposite side

of the viewer, thus the viewer is looking at transmitted light

through the projection surface. There are several types of rear

projection screens ranging from very bright, narrow viewing

areas to very even, wide viewing areas. Several factors must

be considered when deciding which rear projection screen to

use such as the type of projector being used, the brightness

of the projector, projector placement/distance relative to the

screen surface, ambient light level, viewing cone needed and

color of the screen.

Advantages of Rear Projection:

Bright, crisp and high contrast images

Ambient light less of a concern as compared to front

projection because color is typically grey or black (does not

reflect as much light as a light colored surface).

No need to worry about shadows cast from projector.

Screen tends to disappear when image is not projected due

to darker color.

Disadvantages of Rear Projection:

Projector placement behind screen - Space limitation.

Some hot spotting may occur depending on screen sur-

face used.

37Projection Surfaces