Sharpening is one of those parts of digital photography on which everybody has their own opinion. How much, when in the process to do it, using what method, selective vs global, and even whether to apply sharpening at all. Whichever method you choose (or don’t), it’s always good to know multiple methods. When your chosen technique isn’t working, knowing another way can save the day.
In this video, Colin Smith from Photoshop Cafe shows us a sharpening technique using Photoshop’s High Pass Filter. Personally, I love this method, and I’ve been using a variant of this for a few years now. It offers me a lot more versatility than most of the other sharpening methods, and it can be done non-destructively.
Colin’s method is simple and straightforward. Duplicate the layer, apply the High Pass filter to the duplicate with an appropriate radius, then set the blending mode to overlay. Now all you need to do is add a mask and start painting in where you do or don’t want the sharpening effect to appear.
Colin also shows you how to create an action that will allow you to quickly and easily add the high pass layer for yourself with just one click. That way, you don’t have to take the slow route to repeat a bunch of steps on multiple photos.
My own version of this is slightly different. Typically, sharpening is the very last thing I do to an image. So, I’ll select all of my layers and convert the whole thing into a smart object. Then I’ll duplicate that smart object layer and apply the High Pass Filter to that. This way, it’s a Smart Filter, and if I ultimately feel it’s a little too strong or weak, I can go and change the value without having to recreate my mask from scratch.
And, speaking of the mask, I work the opposite way to Colin, by alt+clicking the new mask icon in order for everything to be hidden by default. Then I just paint on the areas I want to be sharp, rather than having everything on and painting the areas I don’t. I also tend to use Soft Light rather than Overlay, as I tend to find it produces a more subtle and natural sharpening effect.
The advantage of using a smart object, for me, as well as the smart filter, is that it allows me to make more tweaks to the image. If the layer is flattened, and then I spot something I should’ve fixed, I have to recreate my sharpening layer. With a smart object, all I do is double click to go into it, make the change, save it, and when I go back to the main image, both the image and sharpening layers automatically update.
I always found it interesting that this method doesn’t seem to be more common than it is, especially with as popular as inverted high pass became for doing the opposite. Sure, that inverted high pass filter skin softening isn’t that great, but regular high pass for sharpening detail can work wonderfully with some practise.