Christie CP2000-X User Manual page 15

Screen Aspect Ratio
CP2000-X User Manual
020-100031-01 Rev . 1 (03-2009)
Table 2.1. Matching Lenses to Screen Size
Lens Type
1.25 – 1.45:1 zoom
1.45 – 1.8:1 zoom
1.8 – 2.4:1 zoom
2.2 – 3.0:1 zoom
3.0 – 4.3:1 zoom
4.3 – 6.0:1 zoom
5.5 – 8.5:1 zoom
Aspect ratio describes the proportion of the display and is expressed as the ratio of

width to height, such as "5:4" or "16:9". Typical aspect ratios range from 1.25 to
2.35—the higher the value, the wider or "less square" the image. See Table 2.2.
Table 2.2. Typical Aspect Ratios
Application
SXGA
35mm filmstrip
NTSC Video / XGA
PAL Video / XGA
HDTV Video
Letterbox Video / "Flat"
Cinemascope
Although image size and aspect ratio can be adjusted using projector controls, it is
still ideal to use a screen with an aspect ratio that closely matches your likely source
material. You can then more easily fill the screen with the image without restricting
either image size or content. For example, standard video from a VCR has a 4:3 ratio
(approximately) and can fill a 4:3 screen without side-to-side stretching, whereas a
high-definition signal with a 16:9 aspect ratio is largest on a 16:9 screen.
Figure 2.8. Aspect Ratios: Images vs. Screens
As shown in Figure 2.7, an obvious mismatch between source material and screen is
characterized by "black bars" on both sides of the image (if the screen is wider than
the source material) or above and below the image (if the source material is wider—
typically called a letterbox display). The black bars are unused display pixels and, in
many installations such as theatres, are masked or hidden behind panels or curtains.
Alternatively, if the area of unused pixels is considered minimal, you may prefer to
use the projector's software control to slightly stretch the image either horizontally or
INSTALLATION AND SETUP
Screen Width (<—>)
10-121 ft.
8-102 ft.
6-83 ft.
5-66 ft.
3-49 ft.
2.5-35 ft.
2-27 ft.
Aspect Ratio
1.25 (5:4)
1.32 (4:3)
1.33 (4:3)
1.33 (4:3)
1.78 (16:9)
1.89 (2048 x 1080)
2.35
2-7