Empty Adjustment Layers

Adjustment Layers and Blending Modes can be an effective combination when applying the enhancement techniques described in Chapter 13, “Enhancement.” Adjustment Layers can used anytime that you would usually duplicate a layer and change its blending mode. As an alternative, you can use a blending mode that's often referred to as an “empty Adjustment Layer.” To do this, create a new Adjustment Layer, but don't move any of the sliders in the adjustment dialog box (so it doesn't change the appearance of the image). This technique works because Photoshop acts as if the Adjustment Layer contains the result of the adjustment being applied. Since an empty adjustment doesn't change the image, it's considered to be identical to the underlying image.

The advantage of using an empty Adjustment Layer over duplicating a layer is that any future retouching that is applied to the underlying image will automatically be reflected in the empty version (Figures 11.30 to 11.32), but will not affect a duplicate layer (Figure 11.33).