Originally posted by biz-engineer I recently exported one out of selected K1 raw files to the print company for a 48" print. After retouching the image (cloning out a few small but unwanted elements) I noticed some elements at the edge of the images were a little fuzzy. Pushing the sharpening sliders improved the situation at edges / corners but the center now looked oversharpned. So I had an idea to have sharpening amount gradually increase from center to edges of the frame to compensate for lens concentric sharpness fall off. To do so I exported two of the same image, with two different sharpening amount, one sharpening amount that suit the center of the image and another sharpening amount to make the image edge look good, then I used a layer mask with gradient transparency so that to mask out the image center of the heavily sharpened image. And that worked great. But that's time consuming. Is there a tool that can gradually sharpen an image from center to edge based on know lens profile such as MTF function at each FL and aperture? (I googled it, and didn't find anything relevant..)
This guy has some interesting videos regarding sharpening and pretty much everything you need when comes to Photoshop. You can start by watching this video and then search for others related to what you want on his channel.
I made an action in Photoshop which is structured based on what I shoot, mostly people, but it is adaptable to any kind of images. Among frecvency separation, dodge&burn (2 types of it), color correction, color grade, etc. there's also the sharpening option (it allows me to do local adjustment instead of general sharpening). You can make a few different actions instead of one and apply the one suited for each image. Most of them will be doing local sharpening anyway.
There are some who will sell you the action if you buy their tutorial. I was very interested in learning Photoshop in the last 4 years and the guy from the below video cover in his Youtube videos 70-80% of the methods used by the ones who sell tutorials (like Phlearn for example). If you are interested in buying very good editing tutorials, both Karl Taylor and Michael Woloszynowicz (Vibrant Shot Photography) have great ones. I named them because they shoot both with high resolution medium format cameras and they put more attention to fine details when comes to overall editing than the popular guys from Youtube.
Hope it helps...