Structure vs Sharpening

[bcf]

I have noticed that if I push the "Structure" slider to a very high value (even 100), and the "Amount" slider of Sharpening to a very low one (say 3), I get what seems to me a very good sharpening, without haloes. Could this be used as capture sharpening? Or as a second stage of sharpening, since it can even be applied locally.

Anyone has the same experience?
What does "structure" do, anyway? ;-)

[Doug Peterson]

It's a mid radius unsharp mask (more or less).

The effect of a USM is partially perceptually cumulative with regards to radius. That is, a mid-radius USM also sharpens detail at a small radius. So adding structure may be balanced by reducing the standard (small radius) sharpening.

Unless you are doing research or art repro or such photography then it's all interpretive - if you like the look structure gives you by all means use it.

[bcf]

Thanks Doug. That's interesting.

But I don't understand how mid-radius USM can also sharpen detail at a small radius. Let's oversimplify… If the radius is say 10 pixels, how can edge contrast be applied to details finer than 10 pixels wide?