Unsharp Mask in the channel
 

Unsharp Mask creates a light or dark halo (heilo) on the edges.

  1. Open unsharpmask1.jpg and experiment with the amount of sharpening
  • Amount = amount of sharpening in general
  • Radius = thickness of halo (heilo) edges
  • Threshold = (brightness of pixels) determines whether or not the edge
    gets sharpened at all (the higher value the more pixels get left out)
  1. Open sharpen.jpg files from unsharpmask folder
  2. Image > Mode > Lab Color
  3. Click on Channels palette and select Lightens channel
  4. Filter > Sharpen > Unsharp Mask... and set: 150, 1.0 and 2
  5. Image > Mode > RGB

This method of sharpening reduces sharpening artifacts.
FocalBlade plugin for Adobe Photoshop

FocalBlade's sophisticated algorithms let you sharpen images without ugly side-effects and give you a lot of control of the sharpening process.  FocalBlade sharpens edges and surfaces in an image independently thereby allowing you to keep objects (e.g. sky, walls, skin and other even surfaces) soft while the overall photo is still sharpened. Unlike other tools FocalBlade doesn't produce halos at high radius settings and even provides sliders for suppressing the white and black part of halos independently. Additionally with FocalBlade you can set the pixel size of details that are sharpened. FocalBlade also lets you keep noise constant or even reduce it when sharpening a photo.