Adobe PHOTOSHOP 5.0 User Manual page 128

120 CHAPTER 6
Making Color and Tonal Adjustments
2 If you're working in an image with more than
one color channel, choose the channel (or
channels) you want to adjust from the Channel
menu. (See "Using the Channels palette" on
page 240.)
To edit a combination of color channels at the
same time, Shift-select the channels in the
Channels palette before choosing the Levels
command. The Channel menu then displays the
abbreviations for the target channels—for
example, CM for cyan and magenta. The menu
also contains the individual channels for the
selected combination.
3 Select Preview to see your changes as you drag
the Levels sliders.
To adjust the midtones, use the gray slider
4
directly under the histogram. Drag the slider to the
right to darken the midtones, drag it to the left to
lighten the midtones. You can also enter values
directly in the Input Levels text boxes, using the
center text boxes for midtones.
Adjusts gamma or gray levels
Click OK.
5
Using the Curves command
Like Levels, Curves lets you adjust the tonal range
of an image. However, instead of making the
adjustments using just three variables (highlights,
shadows, and midtones), you can adjust any point
along the 0–255 scale while keeping up to 15 other
values constant.
You can also use the Arbitrary Map option in the
Curves dialog box to draw a tonal curve by
dragging. This feature lets you create a variety of
interesting tonal and color effects.
For a color illustration of using curves for
tonal adjustment, see the sidebar
on page 231.
To use the Curves dialog box:
1 Open the Curves dialog box (see "Using color
adjustment commands" on page 105).
A
B
C
A. Highlights B. Midtones C. Shadows