We can fall into a rut, at least I do. I was aware of High Pass sharpening but seemed to get away from it. I tend to "automatically" go to USM with settings of 20-60-0 that I learned as a de-fog device. That works very, very fine for muddy or hazy images. This homework reminded me of High Pass and, with some experimentation, reveals significant differences.
I have to look at 100% to clearly see what's happening:

- HW#58 Before.jpg (136.17 KiB) Viewed 119 times

- HW#58 High Pass.jpg (164.42 KiB) Viewed 118 times

- HW#58 USM 20-60-0.jpg (150.68 KiB) Viewed 119 times
When you look at the water coming over the dam and at the wings of the dragonfly, the edge sharpening from High Pass is clearly the better result. I took this image only because of the wide range of bright, vivid color. In this case the "USM De-fog" was clearly unnecessary and, as Michel pointed out, counterproductive. I would have left it alone and missed the improvement High Pass provided.

- HW#58.jpg (120.31 KiB) Viewed 117 times
Rusty