Adobe PHOTOSHOP 5.0 User Manual page 124

116 CHAPTER 6
Making Color and Tonal Adjustments
The RGB equivalent is 10, 10, 10.
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The grayscale equivalent is a 96% dot.
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You can reproduce these same values quickly by
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entering a value of 4 in the Brightness text box.
Click OK when you've entered the values. Then
9
click the shadow area you identified in step 7.
To use Threshold mode to identify the lightest and
darkest areas in the image:
1 Open the Levels dialog box (see "Using color
adjustment commands" on page 105). Make sure
that the Preview option is deselected.
The Levels dialog box displays a histogram of the
image (unless it is an adjustment layer). (See
"Step 2: Check the scan quality and tonal range"
on page 112.)
Note: On most systems running Windows,
Threshold mode works only if the monitor is set to
256 colors. The Video LUT Animation option in the
General Preferences dialog box must be on for
Threshold mode to work. (See "Previewing color
adjustments" on page 106.)
2 Hold down Alt (Windows) or Option
(Mac OS), and drag the white or black Input
Levels triangle.
The image changes to Threshold mode, and a
high-contrast preview image appears. The visible
areas of the image indicate the lightest parts of the
image if you are dragging the white slider, and the
darkest parts if you are dragging the black slider. If
a color channel is selected in the Levels dialog box,
the black area indicates where none of the given
color component exists.
3 Slowly drag the slider to the center of the
histogram to identify the light or dark areas in the
image. Use these pixels for targeting the black
point and white point in your image.