With Adobe Photoshop, there’s numerous ways to do any one thing. And so it is with sharpening.

High Pass filter

When I’m sharpening, I often use the High Pass filter in Photoshop. This is not found with the other sharpening tools, but instead is found under the Filter menu.

High Pass filters are designed to detect edges and highlight them, ignoring areas that are not edges. Perfect. We don’t want to sharpen someone’s skin, the night sky that has no stars, or smooth surfaces, after all! I’ll discuss using a High Pass filter two different ways, the second way with luminosity masks.

Above: zooming in to 200% in Photoshop to see the effect of sharpening using a High Pass Filter.

Five easy steps using High Pass filter to sharpen your image

1. Create a new layer

This will be your High Pass sharpening layer. Try to apply sharpening as the very last step before finishing your photo.

2. Apply the High Pass filter

Accessing the High Pass Filter in Photoshop
Accessing the High Pass Filter in Photoshop.

Go to Filter > Other > High Pass. Your image will turn gray. 

3. Adjust the High Pass filter radius

The High Pass Filter dialog box
Poof! It’s gray! Adjust the Radius to the desire setting.

The dialog box is simple to use. Simply adjust the radius. As you might guess, this simply affects the width of the edge. How far out do you want the sharpening effect to extend? Adjust this until it looks good.

You mostly want to see the edges that you want to sharpen. I find that a relatively small radius value, perhaps between 1.8 to 3.0, often looks the most pleasing. Press OK.

4. Change the filter’s blend mode

Changing the blend mode in the Layers Panel so that the photo appears naturally again and is not gray.
After changing the blend mode, the image is no longer gray. Under the Layers tab, you can see that it is now on Overlay.

It’s still gray! Not to worry. In the Layers tab at the bottom right of Photoshop, change the blend mode from Normal to Overlay.

You should immediately see the original photo, albeit a sharpened one. You may also may try other blend modes, such as Soft Light, Hard Light, Vivid Light or Linear Light. I usually go with Overlay or Soft Light, but I’ve used all of these blend modes at some point.

5. Modify what gets sharpened further using a Layer Mask

Layers Panel. Showing the new Layer Mask after applying the High Pass Filter.
The white rectangle is the new Layer Mask, just to the right of the High Pass filter. Paint a black color on this to hide any part you don’t want sharpened. If you don’t like what you painted, simply undo it and paint again. It’s non-destructive!

Are there any parts of the image in which you want to have less sharpening? If so, you can address this non-destructively using Layer Masks.

To get started, go to Layer > Layer Mask > Reveal All. This will produce a white Layer Mask. Highlight the white Layer Mask by clicking on it, and then begin using your Brush tool with a black color and “paint” the areas that you don’t want to have sharpened. Remember, for Layer Masks, white reveals, black conceals.

Bonus tip: Sharpening using luminosity masks

Now that we’ve touched upon Layer Masks, let’s go one step further.

You can sharpen while using luminosity masks, which targets edges even more specifically. For instance, I like to try to target the edges around the foreground object. I can do this by selecting areas based on brightness or darkness, then create a High Pass filter from that. 

I use Lumenzia for luminosity masks because it’s easy to use and effective.

Illustrating the high pass filter in Photoshop
Above, we are creating a High Pass filter, but the brightness or darkness of the areas is being more specifically targeted by using luminosity masks. Notice that the High Pass dialog box is still the same. The only difference is that we are targeting lightness and darkness in addition to how wide the radius is.

Here, I’ve selected a zone that best accentuates the building. I then select Sharpen. One of the choices is to create a High Pass filter based on the brightness/darkness zone, so that’s what we’ll do.

Layer mask - luminosity masking - used for sharpening (high-pass filter)
To the right of the gray High Pass filter is a Layer Mask. This time, the Layer Mask looks different from the one above, though. It shows dark and light areas as well as edges. Highlight it by clicking on it and then start painting.

This also creates a Layer Mask automatically. Notice that this one is different from the purely white Layer Mask. It’s also masking the light and dark areas that you specified.

From here, if I want to “paint” out areas that I still don’t want sharpened, I can do so, just as I did above.

You don’t need to use Layer Masks. As I mentioned, there’s always several ways to do things. And there’s even several ways we could target what we want with Lumenzia or other luminosity masks. I think part of it is that I find “painting” on the Layer Mask to be quick, intuitive and somehow oddly pleasing. It makes me feel more connected to the image that I am creating.

A night photo of an abandoned waterpark in California, sharpened using Photoshop's High Pass Filter
A night photo of an abandoned water park in California, sharpened using Photoshop’s High Pass filter.