Can anyone point me to where I can learn about sharpening in PP with Camera RAW?
My specific quest is to find out what to look for when sharpening. I don't understand "radius" and how the slider effects it. Should I be increasing or decreasing radius etc.?
Clarity on "luminance" and "luminance detail" as well as the "colour" and "colour detail" sliders would all be much appreciated.
There are a few things to realize. Luminance is a Noise Reduction, not sharpening. It is in fact a blurring operation, which hides noise pixels. So, pay attention to what you're doing.
No blind adjustments.
There is lots of info online, go with that. But...
Nobody listens, but sharpening should be done LAST, the final operation (later, at use time), and specifically honed for the output you are about to do. If you sharpen early, just because you can, then at final time, this may involve resharpening, etc. Should be done last, once, when you know what your use needs. Specifically, after the final resample to final smaller size. There is really no point of sharpening a 24 megapixel image.
You can't use it that way.
Printers print at about 300 dpi, where the video screen is more like 100 dpi. These are different. One size does not fit all. Viewing 100% does not take that into account. You should view it (or check it) as it will be used.
But a video image might be 1000 pixels wide. To print 8x10 might be 3000 pixels wide. These are different.
My notions:
USM Radius is how much it widens the edge. Too much can obscure fine detail. I would suggest around 1.0 for video (maybe 0.6 if much fine detail, to maybe 1.5 if little, but 1.0 is good compromise). More Radius is sharper, but coarser edges, more visible. 1.0 does NOT mean 1 pixel.
And maybe up to Radius 3.0 for printing (1.5 to 3.0). Because printing prints many more pixels in the detail. You have to actually print it to see it, video shows pixels differently (but yes, you do learn what is needed). Again, one size for all is NOT optimum.
Then Amount, often 80 is good. 90 is getting to be a lot. You NEVER want to make the enhanced edges visible, or sharpening noticeable, you just want it to look a bit sharper.... and natural.
I set threshold to 4 or 5, for no good reason.
For video, since they have to be sized smaller, I mostly never sharpen for video, and simply only depend on Adobe BiCubic Sharper, set to be automatic in its resamples. Seems adequate. But a little more can be added time to time.
