Christie roadie 25k User Manual page 13

INSTALLATION AND SETUP
Although image size and aspect ratio can be adjusted using projector software, 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 is largest on a 16:9 screen.
Figure 2.5. Aspect Ratios: Images vs. Screens
As shown in Figure 2.5, 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
most installations, 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 vertically—
enough to utilize the remaining pixels while not noticeably distorting the image.
Using a Cinema "Flat" Screen (1.85 aspect ratio)
By default, source signals closely matching the projector's 2048 x 1080 (a.k.a., 1.89)
display area will fill this area accordingly. Signals with lower aspect ratios will
automatically scale to be as large as possible while maintaining their original aspect
ratio. For details on resizing behavior, see 3.7, Adjusting the Image.
Displaying Both 'Flat" and "Scope"
As an example, two standard types of displays common in theatres—flat and scope—
differ in their width-to-height aspect ratio as shown below:
Figure 2.6. Typical Wide Formats
Achieving either of these displays from a variety of incoming source material (that
may or may not be in the same format) depends on proper settings in the projector as
well as certain room conditions.
Projector Variables: Electronic and Anamorphic Resizing
The native resolution of the projector (1.89) closely matches the aspect ratio of "flat"
source material (1.85). Wider scope material, however, may be "squeezed"
2-7
Roadie 25K User's Manual