Christie GraphXMASTER RPMS-D100U User Manual page 39

OPERATION
RPMS, CS50 & CS70-D100U/UF User's Manual
3-22
Vertical stretch – adjusts the height the image while keeping the width constant.
Use Vertical Stretch to display data from the incoming signal in a different aspect
ratio.
Pixel tracking – adjusts the frequency of the pixel sampling clock, indicated by the
number of pixels per line, so that all pixels generated by a particular source are sampled.
Proper pixel tracking ensures that the image quality–whether good or poor– is consistent
across the screen, that aspect ratio is correct, and that pixel phase can be optimized
(below).
Pixel tracking is adjusted most effectively using a good test pattern, such as a smooth
gray consisting of a clear pattern of tiny black and white dots, or a similar "half on,
half off" graphic image, such as the Windows shutdown screen. Steady flickering or
several soft vertical stripes or bands across the entire image indicates poor pixel
tracking. Adjust the slidebar until the stripes broaden to the point where one large
stripe fills the image. Again, the image may still exhibit some noise.
NOTE: 1) By default, the projector will sample at the correct frequency for most
SHORT CUT:
sources. 2)
Pixel phase – adjusts the phase of the pixel sampling clock relative to the incoming
signal. It is used primarily for adjusting RGB inputs.
Adjust pixel phase when the image (usually from an RGB source) shows shimmer or
"noise". Pixel phase adjustment is done most effectively from within a proper test
pattern, such as a smooth gray consisting of a clear pattern of tiny black and white
dots, or a similar graphic image, such as the Windows shutdown screen. Adjust until
the image is stable and each dot is clearly defined. Using the numbers on the slidebar
as a guide, you will notice that you can actually stabilize the image at more than one
point—i.e., you may find that the image appearance at "11" is identical to the image
appearance at "38", thus you can select either setting.
NOTE: 1) Adjust pixel phase after pixel tracking is properly set. 2)
Pixel
Press and adjust the bottom slidebar.
Filter – applies a low pass filter to the input signal. This removes high frequencies,
which can improve pixel phase noise, but also reduces signal bandwidth. Note that
most signals will not require any filter adjustment—use the filter option only if
standard pixel tracking and phase adjustments do not adequately clear up a "noisy"
signal. For best results:
1. Optimize Pixel Tracking and jot down the value.
2. Optimize Pixel Phase
3. If the image is still too noisy, return to Pixel Tracking and "mis-adjust" so that 2
vertical bands of noise appear, separated by a good center band. See Figure 3.11.
4. Adjust Filter to maximize the width of the good area. See Figure 3.11.
5. Return Pixel Tracking to its correct setting from Step 1.
6. Readjust Phase.
Pixel
Press and adjust the top slidebar.
SHORT CUT: