Christie J Series User Manual page 82

Section 3: Operation
For a source exhibiting overly high black levels (typically caused by a noisy source causing black level spikes)
use the Input Levels menu (shown above). These adjustments, serve as a calibration process compensating for
differences in sources and cabling, to perfect the source image input levels and eliminate the "overshoot" and
"undershoot".
NOTES: 1) Input Levels are of limited use with digital signals, but do offer some ability to tweak poorly
mastered source materials. 2) Input levels apply for the current source only, but for any color temperature
used. 3) Assuming that color temperature has been set up based on the internal test patterns, you can then set
up input levels for a given source so that it matches the color temperature of the internal test patterns.
• Auto Input Level: Use only if you are an experienced user and you have an unusual source that you feel
needs further color temperature and/or input level adjustment. This compensates for incoming out-of-range
drives (white) and black levels (black) that would cause "crushing" of light and dark colors in the image.
After entering a check mark, wait for the six slide bar values to stabilize, then delete the check mark and exit.
The Auto Input Level is automatically turned off upon exit from the Input Levels Menu.
• Black Levels And Drives: To check your image levels and adjust these controls:
IMPORTANT! Do not use Input Levels to adjust color temperature. This will distort contrast and brightness
functions as well as color temperature.
1. Ensure overall "Contrast" and "Brightness" settings are both set to near 50.
NOTE: Not required for "Auto" adjustment.
C
ONTRAST
2. Check the color temperature setup using an internal grey scale test pattern, making sure to obtain a neutral
grey scale.
NOTE: Not required for "Auto" adjustment.
3. Confirm that you are using input on an Analog BNC card or a Dual Link DVI card. Input Levels are not
applicable for sources going through the decoder. A grey scale is recommended.
4. If black levels are too high (and/or whites are too low, which is rare), you likely have a noisy source that is
producing skewed input levels. Enable "Auto" in the Input Levels menu. Wait for all six values to
stabilize. Alternatively, do not use "Auto"; reduce black levels manually instead. Judge by eye and change
one or more of the six levels as necessary to obtain proper blacks and whites. You may want to see only a
certain color while adjusting; use the Auto Color Enable option (described below).
5. Delete the "Auto" check mark and leave the Input Levels menu.
• Auto Color Enable: When a check mark is present, selecting a specific black level or drive to adjust will
automatically enable the corresponding color in the display. Delete the check mark to see all colors, or to
enable a different specific color through the Color Enable control.
• Clamp Location: Brightens the image produced from certain high-resolution high-frequency graphic
sources. The projector automatically selects the best clamp location for most sources. Use the normal Back
Porch location if the image is either sufficiently bright or overly bright. Select Sync Tip if the image appears
unusually dim, if there are horizontal streaks across the image, or if there is significant color drift. This
moves the clamping pulse from the normal back porch location (which is likely too short) to the tip of the
horizontal sync pulse. Tri Level is typically needed for an HDTV source.
• Input Peak Detector: A tool to assist with defining individual input levels, enabling you to accurately set
the Input Levels for any particular source with the appropriate image. Enabling the Peak Detector activates a
special operating mode for detecting only pixels that are considered black or white—all other levels are
displayed as a mid-level grey. When used with a smooth grey scale pattern in which black and white are
known to be at opposite edges of the image, you can watch these isolated areas while adjusting individual
black levels and input drives until both black and white edges are just visible and distinguished from
3-26
RIGHT
= 50 (approx.)B = 50 (approx.)
J Series 2.0, 2.4 and 3.0 kW User Manual
020-100707-03 Rev. 1 (02-2014)