Sharpening an Image
Photoshop CS6 Tutorial
How to Sharpen an Image in Photoshop
It is easy to over-sharpen an image. This method gives you control to set the sharpen amount and sharpen areas within your image.
Open an image in Photoshop (File > Open).
Select the image layer and choose Filter > Sharpen > Unsharp Mask.
With the Preview box checked, watch your image as you adjust the sliders. A good starting point is Amount = 90, Radius = 2 and Threshold = 0. Press OK.
Open the History palette (Window > History) and click the History Brush box for the Unsharp Mask step.
Click the step name just above the Unsharp Mask step. This takes the image back to what it looked like before sharpening.
Select the History Brush tool. Set the Blending Mode to Luminosity in the brush options.
Paint the areas to sharpen with the History Brush. Use a large soft edged brush and vary the opacity if desired.