Adobe 13102498 - Photoshop CS3 - Mac User Manual page 169

Adjusting black and white points with Levels Input sliders
4 To adjust midtones, use the middle Input slider to make a gamma adjustment.
Moving the middle Input slider to the left makes the overall image lighter. This slider adjustment maps a lower
(darker) level up to the midpoint level between the Output sliders. If the Output sliders are in their default position
(0 and 255), the midpoint is level 128. In this example, the shadows expand to fill the tonal range from 0 to 128, and
the highlights are compressed. Moving the middle Input slider to the right has the opposite effect, making the image
darker.
Note: You can also enter a gamma adjustment value directly in the middle Input Levels text box.
Moving the middle slider adjusts the image gamma
Click OK.
5
You can view the adjusted histogram in the Histogram palette.
Adjust color using Levels
Do one of the following to open the Levels dialog box:
1
• Choose Image > Adjustments > Levels.
• Choose Layer > New Adjustment Layer > Levels. Click OK in the New Layer dialog box.
2 Do one of the following to neutralize a color cast:
• Double-click the Set Gray Point Eyedropper tool
Enter the values you want to assign to the neutral gray, and click OK. Then click in a part of the image that should
be neutral gray.
in the Levels dialog box to display the Adobe Color Picker.
PHOTOSHOP CS3 162
User Guide