How To Use The High Pass Filter

The High Pass filter might not be among the most popular Photoshop tools, but it can be quite useful when it comes to sharpening.

This filter is not in the Sharpen menu – you can find it in Other category at the bottom of the Filters menu. The main advantage of the High Pass filter is the fact that it’s pretty straightforward and easy to use. Unlike the Unsharp Mask, the High Pass has only slider you should adjust and it allows for some tweaks even after it’s applied (with layer blending modes!)

Follow these five simple steps if you want to learn how to use the High Pass properly:

1. Edit And Flatten Your Image

The High Pass filter should be among the last ones you apply in your editing routine.

You should edit the image (fix colors, white balance, contrast, etc) before you sharpen it. Once your image is edited and you are happy with the results, you should flatten the layers by going to the Layer menu and selecting Flatten Image.

2. Duplicate The Layer

You should never work directly on your background layer! Because of this, you should duplicate the layer you’ve just flattened. The easiest way to do this is by using the shortcut – CTRL + J (Windows) or CMD + J (Mac).

Before you use the High Pass, you should zoom in to view the image at 100% by pressing CTRL + 1 (Windows) or CMD + 1 (Mac). You need to be at 100% because sharpening is quite easy to overdo and seeing your image close-up with help you avoid such mistakes.

3. Use The High Pass

Now you should be all ready to apply the High Pass!

In order to do this, go to Other category in the Filter menu and click the High Pass. Your image will instantly turn to grey color and you will be able to see what the filter is doing by moving a radius slider.

4. Choose The Amount Of Sharpening

The grey preview will let you see what is being sharpened in your image.

If you pay attention to this preview, you’ll notice that the High Pass filter sharpens only edges. The amount of sharpening will depend on the size and resolution of your image.

For instance, if you’re working with the full resolution of the image, your radius amount should probably be in between 0.5 and 5 pixels. In case you apply too much sharpening, your image will start to get unwanted artifacts, halos, and noise. For the best results, you should keep it rather subtle.

5. Finally, Adjust The Blending Mode

After you have applied the High Pass filter, you should go to Layers palette, select the Blending Mode drop-down and choose Overlay. The grey preview will disappear now and your image will regain its original color. Now you’ll be able to experiment with the sharpened layer by adjusting its opacity and blending modes.

The blending modes you may find most useful are Soft Light, Hard Light, Vivid Light, Linear Light, and Pin Light. In case you find the sharpening too strong, you can easily reduce it by changing the opacity of the sharpened layer.

This means that the High Pass filter is easily adjustable and non-destructive.

In case you don’t need the entire image sharpened, you can also use the Layer Mask and choose the areas in the image where you want the sharpening to be applied.

Because it belongs to non-destructive editing tools, the High Pass filter can be a great choice for anyone who wants to experiment with sharpening. It is also very simple to use and it can make your images crisper in a subtle and rather professional way.

In case you want to learn more about Photoshop tips and tricks, feel free to check out the following links!