The Unsharp Mask (USM) filter in Adobe Photoshop is probably the most well known sharpening technique and the most widely used, however this technique
In this tutorial I’ll try to explain a less popular, but more flexible, technique to sharpen your digital images using the high-pass filter of Adobe Photoshop
1) Open the picture you wish to sharpen in Adobe Photoshop
2) Duplicate the background layer by dragging/dropping it on the “New Layer” icon shown below
3) Change the blending mode of this layer to “Soft Light”
4) Select the background copy layer and go to Filter -> Other -> High pass
5) Start from Radius zero and drag the slider progressively to the right while carefully looking at your picture
6) When you reach the desired amount of sharpening you want applied on your picture click ok
N.B.: The Radius size is highly dependent on your taste and picture size. For an 8 mega pixels photo, I typically use a Radius of 36pixels, a web size picture a Radius size in the 10 – 15 pixels.
7) Now change the opacity of your background copy layer to taste
Click on each picture for bigger size
Why do I prefer this technique ?
1) As mentioned before this technique is none destructive, meaning that it can be undone at anytime since the sharpening is being done on a separate layer
2) I also find this technique more flexible than any other, because it can be faded out/in at will by simply changing the opacity of the layer on which the high pass filter was apllied