The typical last step in editing a photo is to apply sharpening. Sharpening is necessary because photos straight out of a digital camera or scanned film images tend to be a bit ‘soft’. That is, they don’t have the crispness that we may want.
The most common method of sharpening is to use the Unsharp Mask (Filter>Sharpen>Unsharp Mask). The USM filter will be familiar to those who’ve worked in a wet darkroom because it works the same way the unsharp mask worked in making wet prints. USM isn’t necessarily the best way to sharpen a digital photo; however. First, it’s a destructive method of sharpening. That is, it alters pixel values in the image file. This can be worked around if sharpening is applied on a separate layer but even then it’s less than perfect. Second, it can be a bit finicky to use at times. Getting just the right amount of sharpening can be difficult. It’s also easy to overdue the effect. Overcook the sharpening and you’ll end up with unpleasant bright halos around the edges of elements in the photo. Continue reading