Clarity can be a great tool to add or remove local contrast to your photos. When reduced, this has the effect of making the photo look like it was shot with a soft focus. It looks dreamy. When increased, the photo will look grittier and have a hyper-detailed (and often artificial, but hey, this is a special effect) look to it.
Experiment with clarity to see what effects you can create. I like reducing clarity a smidge when I want to make people look better. Conversely, increasing clarity will make most people look very unattractive.
The only way to use Clarity is from the Camera Raw Filter, which is in the Filters menu. I always apply the filter to a Smart Object layer.
My father-in-law took the photo shown in Figure 7.18 when he was in the Air Force, assigned to a base in Canada in the 1950s. I love the repetitive nature of the trees and the stark sky; the hills in the background hint at the scale of the photo.
Figure 7.18 Three different Clarity settings applied to one scene
To show you the effect of Clarity, I have used three different settings on this photo. The first shows settings well into the negative numbers. The second shows the photo with a Clarity setting of zero. The last shows Clarity increased. Notice the first has a wispy look and the last has a definition that borders on harshness.