Checking Gamut
Set the thresho
lds for gamut. (See page 119, To Set Up Gamut Checks.) After
selecting the Arrowhead display, compare the signal to the display to determine
out-of-gamut composite components. Note the following:
Signals exceeding the luminance amplitude gamut extend above the top
horizontal limit (top electronic graticule line).
Signals exceeding the luminance plus peak chrominance amplitude gamut
extend beyond the upper and lower diagonal limits.
The bottom horizontal line shows the minimum allowed luminance level. 0 or
7.5IREforNTSCand0mVforPAL.
Usage Notes
To automate this check, do the procedure Automating Gamut Checks.(See
page 123.)
Checking Luma Gamut
Luma limit thresholds can be configured for identifying luma exceeding threshold
limits. They apply to both the incoming SDI and to the Arrowhead repre sentation
of the SDI input as a composite signal. By defining these levels in percent, they
automatically account for the presence or absence o f setup. The thresholds are
affected by your choice of set-up or no set-up for the Arrowhead display.
Set the thresholds for gamut. (See page 119, To Set Up Gamut Checks.) After
selecting the Arrowhead display, compare the signal to the display to determine
out-of-gamut luminance. Note the following:
The adjustable thresholds are indicated by the dark blue horizontal graticule
lines.
The thresholds are defined in terms of percent of full scale.
The range for the Upper limit is 90% to 108%.
The range to the Lower Limit is – 6% to +5%.
Another useful Arrowhead function is a measure of how well the active video
signal is using the dynamic range of the video channel. A properly adjusted signal
should be centered in the arrowhead graticule and have transitions that approach
all the limits.
Automating Gamut C hecks
You can use alarms to automatically monitor for out-of-gamut conditions.
1. Check that Gamut thresholds are configured as you want them. (See page 119,
To Set Up Gamut Checks.)
2. Press the CONFIG button to display the Configuration menu.
WFM8200 and WFM8300 Waveform Monitors 123
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