Adobe PHOTOSHOP 5.0 User Manual page 114

106 CHAPTER 6
Making Color and Tonal Adjustments
To open a color adjustment dialog box:
Do one of the following:
Choose Image > Adjust and choose the
•
command you want from the submenu.
Hold down Ctrl (Windows) or Command
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(Mac OS), and click the New Layer button in the
Layers palette. For type, choose the color
adjustment command you want, and click OK.
Choose Layer > New > Adjustment Layer. For
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Type, choose the color adjustment command you
want and click OK.
For an existing adjustment layer, double-click
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the adjustment layer name in the Layers palette.
To cancel color changes without closing a
color adjustment dialog box, hold down
Alt (Windows) or Option (Mac OS) to change
the Cancel button to the Reset button; click
Reset. This action—like resetting an
adjustment layer—resets the image to the
default settings (except for the Posterize and
Threshold commands).
Previewing color adjustments
When you make color changes to a selection,
Photoshop usually displays the changes
throughout the entire screen. This happens
because the Preview option is selected and, by
default, Photoshop does not use the video card's
color lookup table (VLUT) in response to your
adjustments. Known as video table lookup, or color
table animation, this process displays an
immediate, but not always accurate, preview of
changes. You can turn off color table animation to
display an accurate preview of color adjustments
to the selected area only.
The following guidelines apply when using color
table animation:
The VLUT is off by default on Windows and is
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not available for most operations on Windows and
Mac OS unless the monitor is set to 256 colors.
For color table animation to work in 24-bit
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mode with Windows, you must install a color table
animation extension, supplied by your video card
manufacturer, in the Plug-Ins directory.
The color table animation feature can cause
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problems in Mac OS if you are using a 24-bit
or 32-bit video card for which certain color
QuickDraw commands have not been properly
implemented. If you have a problem, contact your
video card manufacturer for ROM updates. You
should also reset the video mode and turn off the
Video LUT Animation option in the General
Preferences dialog box.
Image with Preview option off and on