Christie HAL Series User Manual page 8


Choose a screen size which is most appropriate for your lens and application.
2:1 - 3:1 zoom
1.2:1 fixed
1.5:1 - 3:1 zoom
3:1 - 7:1 zoom
Note: Stated screen sizes refer to the diagonal size of a 5:4 screen.

Choose a screen aspect ratio which is most appropriate for your application.
Aspect ratio describes the proportion of the screen and is expressed as a ratio of
width to height, such as "4:3" or "5:4". Ideally, to exactly fill a screen with an
image, the aspect ratio of the screen should correspond to the aspect ratio of the
image, which depends
on the source in use.
For example, standard
video from a VCR has
a 4:3 aspect ratio,
whereas a high
resolution SXGA
signal (1280 x 1024)
has a 5:4 aspect ratio.
See Figure 2-3.
NOTE: With a few exceptions, sources with less than 1280 x 1024 resolution
have a 4:3 aspect ratio. The correct aspect ratio for 1280 x 1024 sources is 5:4.
If you use a mix of sources—i.e., those with the rectangular 4:3 aspect ratio as
well as those with the slightly more square 5:4 aspect ratio—a 5:4 screen will
likely provide the most flexibility. With a 5:4 screen, a 5:4 source image
naturally fills the screen at an established
throw distance. Filling the same screen
with a 4:3 source image requires only a
simple software adjustment to slightly
expand the image to the top and bottom
edges of the screen (Figure 2-4). See 3.6,
Adjusting the Image.
With a 4:3 screen, 4:3 sources will naturally fill the screen at an established
throw distance. Filling the same screen with a 5:4 source image (one from a 1280
x 1024 source) requires a reduction in this throw distance so that the "too tall"
5:4 image no longer spills over the top or bottom of the screen. Once set up in
this manner, all images will then have side borders (Figure 2-5), with most 4:3
images changing aspect ratio as well.
NOTE: For existing installations having multiple 4:3 screens, you can use
Electrohome's EX-1200 or EX-2000 Display Wall controller to fill each screen.
Table 2-1. Screen Size Ranges
2.3’ - 30’ (0.7 - 9 meters)
4’ - 10’ (1.2 - 3.1 meters)
4’ - 30’ (1.2 - 9 meters)
6’ - 30’ (1.8 - 9 meters)
Figure 2-3. Aspect Ratios
Figure 2-4. Adjusting a 4:3 Image
INSTALLATION & SETUP
DLV 1280
User's Manual
2-5