Tue 11-Jan-11 03:59 AM | edited Tue 11-Jan-11 04:01 AM by dm1dave
Camera sharpening is global capture sharpening. As you say, for many images it's good enough. But with with camera sharpening, you can only control intensity. For these reasons (global, limited control), it is often recommended to do capture sharpening as an adjustment step.
I know what you are getting at BUT...
The purpose of Capture Sharpening is to reverse the effect of the AA filter. It IS and should be a global adjustment.
With this degree of sharpening the extra control afforded by using USM has little usefulness unless you have specific problems that need to be addressed. The primary reason USM is recommended is to control noise. If you have noise in an image any sharpening step will make the noise more visible. With USM you can use a smaller radius so that the sharpening has less effect on the noise. If the image is noise free then the radius is not as important.
Another thing to consider is that the in-camera sharpening was designed by people who know exactly how the AA filter affects the image. These in-camera setting were designed to provide optimal capture sharpening based upon the strength of the AA filter.
Your second paragraph you talk about selective sharpening. You are right that what you describe is NOT Creative Sharpening but it is also NOT Capture sharpening it IS Selective Sharpening.
In the post above that you responded to I listed both Selective Sharpening and Creative Sharpening as two separate items (I edited it to be more clear) that both fit in the same area of the work flow. Selective Sharpening needs to be done separately and after Capture Sharpening using a tool such as USM that give you full control.
Don’t get me wrong. I am not saying that my way is best. Using camera sharpening is one of 4 or 5 ways to deal with Capture Sharpening. What works best for one person or one image may not work well for someone else of a different image.