Today’s Question: Can you explain how to use the Sharpen tool to properly apply sharpening to specific areas of a photo? I often want to sharpen the key area of a photo without affecting the sky or an out of focus background.
Tim’s Quick Answer: Actually, I recommend that you not use the Sharpen tool to apply a selective sharpening effect. Instead I recommend using a copy of the image layer in conjunction with a layer mask, using one of the sharpening filters to apply a better effect that also provides you with greater control over the effect.
More Detail: The primary challenge with the Sharpen tool in Photoshop is that you aren’t able to exercise much control over the behavior of the tool. You can of course paint the sharpening effect into the image with the Sharpen tool, so you’re able to specify exactly which areas of the image you want to sharpen versus do not want to sharpen. You can also adjust the Strength setting on the Options bar to control how much of a sharpening effect is applied. And finally, you can determine the extent to which an area of the image is sharpened based on how long you hold the mouse button down while painting in a given area.
Having said all that, the Sharpen tool does not provide anywhere near as much control as the Smart Sharpen or Unsharp Mask filters. Therefore, I recommend using one of these sharpening filters on a copy of the image layer you want to sharpen. You can then use a layer mask to control where that sharpened layer is visible, which in turn will control which areas of the final image actually receive the sharpening effect.
Note that you can get much more information about selections and layer masking to go far beyond the concept of sharpening in a targeted way through the various lessons included in my “Photoshop for Photographers” video course, with “Photoshop Week” details available on the GreyLearning website here:
https://www.greylearning.com/bundles/photoshop?coupon=psweek