High Pass Filter Sharpening has four advantages:
1) Fewer steps
2) Only the edges are affected, where sharpening is most needed.
Expanses of even tones and colors, where sharpening isn't needed, are ignored.
3) Noise is not sharpened.
4) Selective sharpening, applying sharpening to only certain areas, is easy.
High-pass sharpening works like this.
1) Edges are located like the Find Edges filter (Filter > Stylize > Find Edges).
2) The Overlay blending mode lightens lighter edges and darkens darker edges.
The contrast is increased along the edges, which we see as sharper.
Be sure to check off as you go along.
A composite layer contains all of the layers of your photograph.
Do the following.
a) Deselect the eye icons on the layers you don't want to merge.
b) Make sure the top layer is active (highlighted).
c) Select > All.
d) Edit > Copy Merged.
e) Edit > Paste.
If you haven't already done so, go to Composite Layer.
Go to Enhance > Adjust Color > Remove Color, or press Shift + Ctrl + u.
At the top of the layers stack, look for the unlabeled Blending Mode box.
It's to the left of the Opacity box.
If you're new to blending modes, go to Blending Modes.
3 is the maximum sharpening value.
You may need to reduce the sharpening.
A landscape may look good with more sharpening.
If you're working on a portrait, reduce the sharpening.
You can also reduce the sharpening by using Soft Light, or increase it with Hard Light, instead of the Overlay blending mode.
Go to Evaluating Sharpening.
The next section discusses selective sharpening.
You can apply sharpening to parts of a photograph.