Specifications

Appendix C Display Issues 245
If using a CRT or known good LCD display makes the video playback look
considerably smoother, you’re most likely experiencing synchronization prob-
lems introduced by the display or projector (see above).
BANDING This section deals with banding in smooth areas, either within a static image or
in the overlap area of projected images.
Gradients When displaying images with smooth areas and gradients, limited resolution
in the display may cause visible bands to appear. A good way of testing this is
to display a smooth grayscale ramp, as in the example shown to the left. Such
an image can easily be created in applications such as Adobe Illustrator or
Photoshop. You may also want to create test images with vertical or radial
gradients.
If such test images appear smooth on a good monitor, while exhibiting
banding using your display device, the signal resolution of the display device
is insufficient to reproduce all the steps in the gradient. Such problems are typi-
cally associated with low end, office grade projectors. Often, using a digital
interface may avoid or solve such problems since it circumvents the analog-to-
digital conversion step, which may be causing the loss of definition (see “DVI
Connector” on page 242).
Rear Projection When using rear projection, banding may be caused by the screen material.
This may also occur when using high-gain front projection screens. Such
banding can be identified by the fact that it moves with you as you walk along
the screen.
The only way to avoid or solve such problems is to use a different screen mate-
rial. Suitable low-gain screens for both front and rear projection are available