High Pass Sharpening

I picked up a new method for sharpening that I’ve found super useful. If you use a DSLR that isn’t full-frame, or a camera that produces lots of noise or is bad in low-light scenarios, this method is for you. I use Photoshop CS3 Extended, but this will work with any version that has the High Pass filter.

Instead of going to Filter > Sharpen > Smart Sharpen, I found out you can use the super versatile High Pass filter instead. This sharpens the edges of your photos, but doesn’t sharpen the background noise, and it keeps good blur intact from your depth of field. That last bit is important for me, because I primarily shoot portraits using my 50mm, so depth of field can make or break a shot.

Open up your photo: I’m using an old photo of lilacs as my example. This particular photo doesn’t have a ton of noise, but it does have a depth of field that I want to keep when resizing.

Resize your image, and then duplicate the layer. Layer > Duplicate Layer or Ctrl + D

Then desaturate the duplicated layer. Image > Adjustments > Desaturate or Shift + Crtl + U

Now go up to Filter > Other > High Pass.

Now, for this step, you just want to remember to use a low value. Move the slider to the left, so that you can just barely make out the outlines of your photo.

Now set the blend mode of that layer to Overlay or Soft Light, depending on your image. You can also take the sharpening down a few notches by adjusting the layer opacity.

I’ve also processed the image further, adding contrast, vignetting and a very subtle cross processing effect to make the purples really pop:

Hope that was helpful. A Photoshop action could also be set up to do this, just make sure you’re able to adjust the level of the High Pass Filter.