What is 20>50>0 sharpening?

I've been trying to find the perfect sharpening method...aren't we all, and I recently was given this formula, but don't know what it means. I don't have CS anything only elements 7. Does someone have instructions on what to click on in elements? I've done the downsizing, then oversharpen using unsharp mask, then resize again, works better than previous ways, but I'm wondering if I'm missing something.

This setting in the Unsharp Mask mode (available in Elements) doesn't actually sharpen an image at all. Instead, it applies a 'local contrast enhancement' that can often make images 'pop' a bit more. I try this step on all of my images...sometimes it works, sometimes not. Gotta be careful, though. If any areas of the image verge on overexposure, this step will push those areas right off the edge. Keep an eye on your histogram when using this technique.

Here's a Luminous Landscape article explaining local contrast enhancement. I use it quite a bit, although the "Clarity" slider in ACR does something similar if you work with RAW files and have that slider in Elements.

Also, it doesn't have to be 20/50/0....I've used anything from 10/20/0 to 50/200/0. Obviously the effect varies greatly so it depends on what you want the image to look like. (The "0" for threshold essentially just means that it gets applied everywhere. So that one is least likely to change, although upping that could sort of filter the effect based on the image data.)

Thanks guys...I did a little experimenting and wondered why the contrast upped itself...thanks for the explanations.

There have literally been volumes written on sharpening so it's a very deep and varied subject. Regarding USM, it sounds like you're satisfied but here's a little more info for you in case it helps. It is an oversimplification so please "pros" don't hammer me, but I think captures the essence of what's happening.

The software looks to detect edges in the image based on a difference of tonality. When you apply USM, the software applies a lighter tone to one side of the edge and a darker tone to the opposite side. The "amount" determines how dark/light this applied tone is. The "radius" determines how far the applied tone is allowed to extend from either side of the detected edge. The "threshold" tells the software how much difference in tone there needs to be before it even considers something to be an edge. Hope that doesn't sound too abstract. It's much easier to demo than explain in writing. If this doesn't help, just ignore it. If it does, great!

John

My favorite text on sharpening is the late, Bruce Fraser's "Real World Sharpening." He did the best job of explaining this stuff in detail, but understandably of any resource I know.