Sharpening Your Images the Old-School Way
Using the High Pass to sharpen images is an old-school method to sharpen your images. The benefit of sharpening your images this way, instead of using an unsharp mask or a smart sharpen or one of the other sharpening filters, is that a high pass sharpen takes place on its own layer. It can be masked in or out depending on which parts of the image you want sharpened, you can set the opacity, as well as the depth of the effect depending on which blending mode you set it to. Here’s how to do it:
Duplicate the layer you want to sharpen.
Select Filter > Other > High pass.
Move radius so that you can see the faint outline of the area you want to sharpen.
You may see some colour artifacts along the edges so go to Image > Adjustments > Hue/Saturation and move the saturation slider all the way left so there is no colour left in the high pass layer.
Change the blend mode of your high pass layer to overlay (for a stronger effect) or soft light (for a less intense effect).
You can see the difference in this before and after image below.