Adobe 13102498 - Photoshop CS3 - Mac User Manual page 172

If the Curves dialog box is set to display levels rather than percentages, the highlights are represented in the top right
corner of the graph. Moving a point in the top portion of the curve adjusts the highlights; moving a point in the
center of the curve adjusts the midtones; and moving a point in the bottom section of the curve adjusts the shadows.
To darken highlights, move a point down near the top of the curve. Moving a point either down or to the right maps
the Input value to a lower Output value, and the image darkens. To lighten the shadows, move a point up near the
bottom of the curve. Moving a point either up or to the left maps a lower Input value to a higher Output value, and
the image lightens.
Note: In general, only small curve adjustments are necessary to make tonal and color corrections to most images.
Do one of the following:
1
• Choose Image > Adjustments > Curves.
• Choose Layer > New Adjustment Layer > Curves. Click OK in the New Layer dialog box
2 (Optional) To adjust the color balance of the image, choose the channel or channels that you want to adjust from
the Channel menu.
To edit a combination of color channels at the same time, Shift-click the channels in the Channels palette before
choosing Curves. The Channel menu then displays the abbreviations for the target channels—for example, CM for
cyan and magenta. It also contains the individual channels for the selected combination. This method does not work
in a Curves adjustment layer.
Note: Select Channel Overlays in Curve Display Options to see the color channel curves superimposed on the composite
curve.
Add a point along the curve by doing one of the following:
3
• Click directly on the curve.
• (RGB images only) Ctrl-click (Windows) or Command-click (Mac OS) a pixel in the image.
Ctrl/Command-clicking pixels in the image is the best way to add points when you want to preserve or adjust specific
details in an RGB image.
To identify areas in the image that are being clipped (completely black or completely white), select Show Clipping.
You can add up to 14 control points to the curve. To remove a control point, drag it off the graph, select it and press
Delete; or Ctrl-click (Windows) or Command-click (Mac OS) the control point. You cannot delete the endpoints of
the curve.
PHOTOSHOP CS3 165
User Guide