Sometimes, when I already have made some edits in Photoshop and find that I missed out some small areas when using the auto-mask in Lightroom, it was a pain using a brush to fix it.
Turns out that Photoshop not only has an equivalent to the Lightroom auto-mask feature but, it is far more powerful in the way you can control how the auto-masking works.
So, without spending any more time on explaining this, let us open a raw file in Photoshop and see how this works…
Nitin Chandra's Blog 