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Digital photographs are a little soft by nature. Most require at least one pass of sharpening, and often require more than one to look their best on the web. In this tutorial, I am going to show you the LAB Color Mode sharpen technique. This is a more subtle sharpen, that has a little more control over haloing and artifacts than a simple Unsharp Mask.

4. LAB Sharpen
After you have finished processing your image, make a single layer copy of the visible image by doing a “Stamp Visible” command (Ctrl + Alt + Shift + E).

Now take the layer that was created by the Stamp, and duplicate it to a new image. To do this, go to Layer > Duplicate Layer and choose New in the Destination drop down.

Next, change the Color Mode to Lab by going to Image > Mode and picking Lab.

After you change to LAB mode, select the Lightness Channel. When it is selected your image should appear black and grey.

Now, apply your Unsharp Mask by going to Filter > Sharpen and select Unsharp Mask. Once that is open, start adjusting your sliders. There is no set number that will work for your image, but a good range to try is Amount between 75 and 150, Radius between 1 and 3 and Threshold between 0 and 2. For this example I used Amount 102, Radius 1.8 and Threshold 2.

At this point you can either change it back to RGB Color mode (Or whatever you used for the main image) and save it if you are happy with it, or you can copy this layer back to the original and work with masks to get it a little cleaner.

I am going to just convert back to RGB Color Mode by going to Image > Mode and picking RGB Color.

And here is the before and after. Click on the image for a larger view.