Using Help
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137
Adobe Photoshop Help
Making Color and Tonal Adjustments
Using Help
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Contents
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Index
Back
137
3
Enter a value in the Opacity text box. Values can range from 0 to 100%. Use this setting
to reveal more or less of the underlying image through the warning color. Then click OK.
Original image, and preview of out-of-gamut colors
Using the Levels dialog box
The Levels dialog box lets you correct the tonal range and color balance of an image by
adjusting intensity levels of the image’s shadows, midtones, and highlights. The Levels
histogram serves as a visual guide for adjusting the image’s key tones.
Using Levels to set highlights, shadows, and midtones
You can set the highlights and shadows in an image by moving Input sliders to the first
group of pixels on both ends of the Levels histogram. This maps these pixels—the darkest
and lightest pixels in each channel—to black and white, increasing the tonal range of the
image. The corresponding pixels in the other channels are adjusted proportionately to
avoid altering the color balance. You can use the middle Input slider to change the
intensity values of the middle range of gray tones without dramatically altering the
highlights and shadows.
Although the Levels sliders are not as exact as assigning target values or using the Curves
dialog box, they often yield good results.
To adjust tonal range using Levels:
1
Open the Levels dialog box. (See
“Making color adjustments” on page 132
.)
2
To adjust tones for a specific color channel, choose an option from the Channel menu.
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. You can only
edit spot channels and alpha channels individually.
3
To adjust the shadows and highlights manually, do one of the following:
•
Drag the black and white Input Levels sliders to the edge of the first group of pixels on
either end of the histogram. You can also enter values directly into the first and third
Input Levels text boxes.
•
Drag the black and white Output Levels sliders to define new shadow and highlight
values. You can also enter values directly in the Output Levels text boxes.
