User manual

19 • GRAY BALANCE AND COLOR CAST
175
ColorQuartet 5.0 Pro
19•Gray balance and color cast
Gray Balance • Overview
What it is
In conventional color repro, gray balance refers to the proportions of the three process colors
(cyan, magenta and yellow) that are necessary to produce a neutral gray in the printed image.
The same principle applies to red, green and blue if the image is reproduced in RGB format.
• If the gray balance is not correct, so that one of the three process colors is dominant, the image
is said to have a color cast.
• Color cast is normally considered undesirable, but it is sometimes used deliberately to
achieve a special effect.
Gray balance in ColorQuartet
• To neutralize the lightest and darkest portions of the image during automatic scanning, acti-
vate Highlight/Shadow in the Auto Functions section of the Magic
Touch window.
• Aside from this, ColorQuartet includes five functions, all accessed from the Color menu or the
tool bar, that influence gray balance:
• In addition, the CMYK Gray Balance window, accessed from the Color menu, displays the gray
balance of the image. It plots the original’s L*
or density values against the reproduction’s dot
percents.
• The gray balance functions can be used to reduce, neutralize or introduce color cast to
achieve the desired image effect. Which function you use depends partly on your personal
choice of working methods and on how much you know about color modification. For exam-
ple, the CMYK Curves are mainly intended for people who are used to working directly in
CMYK values without necessarily needing visual feedback.
>>> Next step:
Checking for and changing color cast
Changing gray balance with the “Gray Balance” window
Changing gray balance with the “Highlight/Shadow” window
• Gray Balance
• Highlight/Shadow
• Introduce Cast
• CMYK Curves
• RGB Curves