Step 5

Now you can see that you applied a copy of the image into the layer mask. Between the layer mask and the layer thumbnail, you should see a symbol that looks like a chain. Click on that and it'll unlock the layer mask from the layer. What this does is let you modify the laeyr mask without anything changing on the actual layer. For example, if you had it linked with the chain icon showing, if you move the layer mask, the layer will move too. But when you unlink them, when you move the layer mask, the layer won't move.

Step 6

Now here's the key part to this sharpen edge technique. The Find Edges filter. This filter will create a sketch of the outlines. So lets apply this filter. Go to Filter> Stylize> Find Edges. Your layer mask should now have an outline.

Step 7

In the layer mask, the white areas mean that the layer will show and the black areas mean that it won't show. So right now, we have the outline as black meaning that the edges won't show. We want the opposite so we'll invert the layer. To do this, press Ctrl+I or go to Image> Adjustments> Invert.

Step 8

Now that we have everything setup, we can sharpen the layer. Click on the layer thumbnail to activate the layer and deselect the layer mask. Now go to Filter> Sharpen> Smart Sharpen. If you don't have Smart Sharpen, you're probably using an older version of Photoshop without it but you can use the Unsharp Mask instead that you can find in Filter> Sharpen> Unsharp Mask. With the tool, sharpen the image. Here's what the Smart Sharpen filter looks like. When I sharpen it, the filter preview shows that there are lots of halos and the skin becomes sharpened too. But if you move that window to the side and look at the document window image behind it, you can see that it only sharpened the edges. Here you can see the big difference between the normal sharpening method and the sharpen with edge mask method by comparing the image on the sharpen window and the image in the Photoshop document window.