Understanding Sharpening in Camera Raw and Lightroom
Canon 1Ds MKIII with 100-400mm f/5.6 L IS
Digital image sharpening is often the least understood aspect of image processing, yet it is as well among the most important. The reason for this is that every image has different sharpening requirements, and each use, whether a 16X20" exhibition print or for use on the web, requires different amount of shapening applied at different times in the image processing process. No wonder so many people simply shoot in-camera JPGs and say the hell with it.
There are automated solutions. Among the best of these is Photokit Sharpener from Pixel Genious. I've been using this Photoshop plug-in for years and can hardly imagine working without it.