How to Sharpen Your Digital Photo in Image-Editing Software
Use your image-editing program’s Sharpen tool, if it has one, to paint sharpness in only those places in your digital photo where you want things to look clearer or crisper. To use a Sharpen tool in your image-editing software:
Turn on the Sharpen tool by selecting it from your image editor’s toolbox or menu.
This figure shows the Sharpen tool selected in Photoshop Elements.
Set your brush size, as shown in this figure.
The size you pick controls how big an area is sharpened with each click or drag of the mouse.
Set the strength for your sharpening effect.
A good default value is 50%, but you can raise or lower that level as needed by dragging the slider or other control, as this figure shows.
Click or drag over the area that you want to sharpen.
Clicking sharpens an area the size of your brush tip, and dragging allows you to sharpen in a freeform area, following an edge or working within a desired region of the image (like in this figure).
To keep the sharpening results as subtle as possible, avoid using a very small brush size (10 pixels or fewer) if you’re sharpening an area that’s more than 20 pixels wide and/or tall. Otherwise, you see your brush strokes where you applied the sharpening. Too much sharpening can also result in bizarre-looking bright pixels that end up hiding details because the individual pixels stand out too much. Sharpening can also increase your file size.