High Pass Sharpening in Photoshop

High Pass sharpening is a lesser-known technique that enhances detail while minimising overall noise. Follow these steps to apply High Pass sharpening in Adobe Photoshop:

Step-by-Step Guide

1. Launch Photoshop and open the image you want to sharpen.
2. Duplicate the Layer: Right-click on the background layer in the Layers panel and select Duplicate Layer…. Rename it to “High Pass” or something similar for clarity.
3. Apply High Pass Filter: With the duplicated layer selected, go to the menu and click on Filter > Other > High Pass.
4. In the High Pass dialogue box, look to adjust the Radius slider. A radius of around 1–3 pixels typically works well with higher resolution images. This value can be increased for images with lower image resolution. Adjust the slider slowly to check for haloing. Click OK once you’re satisfied.
5. Change Layer Blending Mode: In the Layers panel, change the blending mode of the “High Pass” layer to Overlay or Soft Light, depending on the image contrast. This allows the high-pass details to blend with the original image.
6. Adjust Layer Opacity: If the sharpening effect is too strong, reduce the layer opacity to soften the effect to your liking.
7. Finalise the Image: Review the image to ensure the details are sharp but not excessively so. When you’re satisfied, save your work.

Additional advice for Effective High Pass Sharpening

Best practice is to use a Duplicate Layer: Always work on a duplicate layer, as mentioned above. This allows for easy adjustments without altering the original image.

Zoom In: When adjusting the radius, zoom in to see the details more clearly.

Overlay: Enhances contrast by brightening and darkening areas. Can produce a more pronounced sharpening effect; however, it can lead to more visible artefacts and haloing if overdone.

Soft Light: Provides a gentler, more subtle effect. It also enhances contrast but without exaggerating detail, resulting in a softer appearance. Best for portraits and subtle detail enhancement.

Control with Masks: If certain areas are too sharp, use a layer mask to selectively apply sharpening.