"Curves" is the most powerful adjustment command in Photoshop. Although its functionality and work principles are very similar to those of "Levels", this method let us editing virtually any tonal range, or even adjusting several different ranges in different ways. Please note, though, that when unlocked in Photoshop Elements 6, this tool has 2 important restrictions - it only edits current layer and current color channel.
How to adjust image tone:
- For a layered document, select the proper layer in the Layers palette.
- In the Effects palette, double-click the "Curves" thumbnail. There appears dialog box allowing you to adjust image tone by editing the graph. Generally speaking, the sharper your graph is, the more contrasting image you get.
- Very carefully pull some middle point of the graph to brighten or darken the image midtones.
- Pull the graph at some lower point rightward to decrease brightness in the darker areas (let's say, in "mid-shadows").
- Uplift the upper segment to brighten the "mid-highlights" (screenshot).
- To define tonal range more precisely, [Ctrl]-click a specific spot on the image. Then pull the graph at the added point to adjust the selected range.
