NewTek Tricaster TCXD850, Руководство пользователя, Страница: 313 / 336

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As it happens, from the vectorscope point of view, neither black nor white properly have any
color saturation. Thus with the lens cap on (or with a white card filling the viewfinder), the
vectorscope should show only a small fuzzy trace at its center. If the fuzzy dot is off-center
horizontally or vertically, this would indicate that the camera is incorrectly calibrated, actually
tinting gray areas.
When the trace is off center, the direction and distance of the offset tells us what sort of tint
(and how much) is represented by the deviation. You may be able to use the color controls at
your camera to correct for this offset, or you can use the
U Offset and V Offset controls in
TriCaster’s Proc Amp to do so (as always, source controls are best). Adjustments to U Offset
move the trace left or right, while V Offset changes adjust its vertical position.
Let’s move on to a slightly more rigorous testing.
C.2.3 COLOR METRICS
At this point, we’ve assured ourselves that the signal from the camera is neither too bright nor
too dark, that its output falls within broadcast legal luminance limits, and that the black & white
part of the signal does not have an unwanted color cast.
We haven’t done anything yet, though, to assure our reds are red, not slightly brown, or that our
blues are not slightly green or magenta, etc. The Vectorscope can provide much more specific
information about your cameras color signal. Let’s see how it can assist you to ensure your
colors are accurate.
USING COLOR BARS
You’ll no doubt have seen the familiar color bars used as a standard reference for video signal
calibration. Two examples are shown here. Figure 219 is an example of the color bars used in
NTSC countries, while Figure 220 is a PAL example, common throughout European nations.