Auto-Align Layers

The Auto-Align Layers command uses the same technology as Photomerge to align layers automatically. The only slightly odd thing, in my opinion, is that this layer-based function is found under the Edit menu. This function is wonderful when you have created a document with several layers and you want to align them all. For example, say you shoot several family photos moments apart and you need to swap heads so everyone has their eyes open.

Using Auto-Align Layers is pretty simple: In the Layers panel, select all the layers you want to align. Then, choose Edit > Auto-Align Layers. In the dialog, choose a Projection method—I use Auto 99.99% of the time—and click OK (Figure 2.16). Photoshop moves and rotates each layer so that the consistent elements line up.

Figure 2.16 The Auto-Align Layers dialog.

Once the layers are aligned, you can use masks, the Clone Stamp tool, and other options to complete the effect. This is a great example of letting Photoshop do some of the work for you and then manually finishing off the project.