ABSTRACT
Adjustment layers Nearly all the image adjustments you see listed in the Image ➯ Adjustments menu can also be applied as adjustment layers via the Layer menu or Layers palette (see Figure 6.1). Adjustment layers offer the ability to apply multiple image adjustments and/or fi lls to an image and have these changes remain ‘dynamic’. In other words, an adjustment layer is an image adjustment that can be revised at any time – adjustment layers enable the image adjustment processing to be deferred until the time when the image is fl attened. Adjustment layers always have an active layer mask, which means that whenever an adjustment layer is active, you can paint or fi ll using black to selectively hide the adjustment effect, and paint or fi ll with white to reveal. Adjustment layers are savable in the Photoshop native, TIFF and PDF formats, they add very little to the overall fi le size and best of all, provide limitless opportunities to edit and revise the adjustments that are made to an image. If you want to dodge or burn a photograph, i.e. make a localized correction to darken the sky or lighten someone’s face, then the best way to do this is by using a masked adjustment layer. In the technique shown here, I added an adjustment layer that darkened the image as a whole and then fi lled the adjustment layer mask with black to hide the layer adjustment and painted (or in this case, partially fi lled) the adjustment layer mask with white to selectively apply the image adjustment layer to the photograph. Working with adjustment layers is by far the best way to shade or lighten an image. This is because you have the freedom to re-edit the adjustment layer to make the adjustment lighter or darker. And you can edit the mask associated with the adjustment to redefi ne the areas you want to adjust. In the following example I show you how to use a Levels adjustment layer to create a darkening vignette, but you could also use a Curves adjustment layer. Either technique will work just as well here.
