Using the High Pass Filter to Create a Soft Effect

The high pass filter is often used for sharpening images but it can also be used to have an opposite effect, which is to soften the details of an image. The softening can be applied to the whole image or just selected areas, leaving key details sharp and focused.

A soft, diffused look is often used when you want to soften the texture of skin or if you want to create a dreamy effect. In this tutorial, we will explain how the high pass filter can be used for this purpose. Photoshop CS2 is the photo editing program used but other programs that include the high pass filter will also be sufficient in getting great results.

Step 1:

Open your image and create a duplicate layer. If you have an existing image opened that has adjustments, create a new layer with a flattened version of the image. Click on the top layer to target it and then click Layer > New > Layer. Choose the new layer you created and press Ctrl + Alt + Shift + E (if on a Mac it is Command + Option + Shift + E).

Step 2:

Go to Filter > Other > High Pass and a dialog box will pop up showing an image preview and the radius settings below it. Note that the higher the radius value, the softer the image will turn out. For this tutorial we will be setting the radius value at 15.

Step 3:

Now time for some diffused lighting! Go to Image > Adjustments > Invert so that only the areas that were untouched by the filter will be affected. Go to the Blending Mode dropdown list at the Layers Palette and choose Soft Light to produce a soft focus look. If you are happy with the overall appearance of the image, this can be your final adjustment. But if there are areas you prefer to remain sharp then proceed to the next step.

Step 4:

For this next step, we will be creating a layer mask where we can show the parts of the underlying layer which are still defined and clear. By clicking on the Add Layer Mask icon found at the bottom of the Layers palette, a layer mask is added. This appears as an empty white rectangle beside the active layer.

Step 5:

Now go to the Brush tool and set the Hardness to 0% so that the edges are at their softest. Keep the mode at Normal, the foreground color should be black and have the Opacity at around 80%. The brush diameter should be just large enough to trace the details you want to keep sharp without affecting the irrelevant areas. With the brush, paint over the areas that you want to remain sharp. You will notice that the sections you are painting are revealing the matching areas of the layer beneath it which are sharp. These parts that you are brushing will appear black in the layer mask.

Note that if you think you overdid the brushing and want the revealed areas to be more hidden, just set the foreground color to white and paint over the selected areas. This will bring back the details from the top layer. To lessen the strength of the overall blurriness, you can adjust the opacity or fill to a lower degree.

Using the High Pass Filter to soften images is just one of many ways to achieve similar results in Photoshop. Also, some images could benefit more with other soft focus techniques compared to the High Pass option so if you don’t like how your image turns out with this method, try experimenting with other options.