Sharpen or USM

[MP Guy]

What is the difference between using the sharpening filter or USM?

Thanks

[back alley]

here

and here

more

i'd just tell you but i haven't actually read these myself yet

joe

[dmr]

It's my impression that sharpen just increases contrast at edges, but unsharp mask mimics the wet darkroom unsharp mask technique, which I've never done but read about.

[Pherdinand]

dunno the difference in theoury but USM works for me, i always use it (flatbed scan needs it desperately)

[Marc Jutras]

I use a a second layer (copy of the original) in Overlay (or Soft Light or Hard Light depending on the effect) and apply a High Pass filter on it. The radius of the filter determines the amount of sharpening. Normally, it affects only the edges and not the noise.