Creating an adjustment layer

Adjustment layers can be added to an image to apply color and tonal adjustments without permanently changing the pixel values in the image. For example, if you add a Color Balance adjustment layer to an image, you can experiment with different colors repeatedly, because the change occurs only on the adjustment layer. If you decide to return to the original pixel values, you can hide or delete the adjustment layer.

Here you’ll add a Curves adjustment layer to create a greater contrast between the grille and the rust layer behind it. You’ll do this by darkening the entire rust image. An adjustment layer affects all layers below it in the image’s stacking order. Because you’ll place the Curves adjustment layer below the Metal Grille layer, the adjustment will affect the Rust layer and the Background but not the metal grille.

1.	Select the Rust layer in the Layers palette.
2.	Click the Create New Fill Or Adjustment Layer button () at the bottom of the Layers palette and choose Curves from the pop-up menu.
3.	Click the middle of the diagonal line in the grid (the color curve) to add a control point on the curve that will adjust the midtones.
4.	Drag the control point down and to the right or enter values in the Input and Output text boxes. (We moved the control point so that the value in the Input text box was 150% and the value in the Output text box was 105%.)
5.	Click OK to close the dialog box. An adjustment layer named Curves 1 appears in the Layers palette. The thumbnails for the new layer include one of the Curves 1 graph and one of the layer mask.
6.	Choose File > Save.

You can experiment by clicking the eye icons for the Curves 1 and Rust layers off and on, to see the effect of the adjustment layer on the other layers. When you finish, be sure to return all layers to their visible state.