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(Brightness, Contrast, Color, and Tint) are pressed. U stands for Unity, or perhaps Unchanged. In either
case, it shows that the signal passing through that particular control is being neither boosted nor cut. To see
the settings for another control, press either one of that control’s buttons. To change the settings, press the
up and down arrow buttons.
You can see the extent of color processing available in this section by experimenting with the controls.
Brightness has to do with how light or dark the colors in the image will appear at the Video Output. The
Contrast controls affect the range between the lightest and the darkest parts of the image, including how
much shadow and highlight detail can be seen. Color controls the saturation or intensity of the color image,
from fully saturated or extremely intense at the top of the scale to completely desaturated or monochrome
(black and white) at the bottom. The Tint buttons (NTSC only) control the actual hue or specific colors in the
image, in effect rotating all the colors equally around an imaginary color wheel.
The up and down Tint buttons do double duty as Reset and Reset All. Reset works on the selected input
source, and when pressed and held for 2 seconds, resets the Color Processor controls and R.G.B. white
balance corrector for just that input to U or unity. (Press and hold the Reset button until you see the image
shake a bit and return to it’s unprocessed state.) Reset All is activated the same way, but resets the Color
Processor and RGB Corrector settings on all 4 inputs to U or neutral.
But how do you know for certain how effective any of these adjustments are? You can see the changes by
looking at the Main Output on a video monitor, but how do you know if that reference is accurate?
The first part of the answer is: by having an accurately calibrated monitor that shows exactly, with reference
to a standard, what the video looks like. That standard has been described and agreed to by the Society of
Motion Picture and Television Engineers (SMPTE) and the European Broadcasters Union (EBU), and is
most commonly shown as “color bars.” Color bars are an image consisting of columns and blocks of specific
colors and gray tones. Because of differences in television standards, SMPTE bars and EBU bars do not
look the same. They are used in much the same ways: when these are displayed on a monitor, the monitor
can then be adjusted to meet the standard.
The most serious, accurate color correction is done with the aid of a waveform monitor/vector scope, a
signal analysis instrument (actually a pair of instruments) common in video editing suites, which shows
precisely the details of the video signal. With one of these instruments, you can see at a glance (once you
know what you are looking for) the most intimate electronic details and irregularities of the video signal.
Many users may not have access to a waveform monitor or vector scope, but this does not necessarily
condemn them to produce less than high quality video. It means that more care must be taken and some
different procedures must be followed.
Nothing will take the place of a calibrated, properly adjusted monitor, so that must always be your first step.
For more information on monitor calibration procedure, see
Appendix: Monitor Calibration
, page 55
.
