Can someone explain "how" this works? I use it to sharpen my pics a lot, but I don't know why it works or what the values are. I just move them around until I like what I see....
I found this Quicktime video on Apple's website that is a good, concise overview of the Photoshop unsharp mask tool, what the values mean, and how they can be applied to various images. Runs about 5 minutes or so; very informational.
Here's an article that breaks down the various components and shows their effect on a simple shape. Many people recommend applying the USM in lab mode on the luminosity channel.
