Focus Peaking

Focus Peaking highlights sharp edge detail in the current image. It is a visual aid for checking whether the important part of the photo is in focus.

How to Use It

  1. Open an image in zoom view.
  2. Turn on the focus mask or focus peaking overlay in the image controls.
  3. Inspect the highlighted areas.
  4. Adjust Focus settings if the overlay is too weak or too busy.

For best results, use extracted JPG previews or RAW-based zoom previews instead of small thumbnails.

Settings

Focus controls are in RawCull -> Settings -> Focus.

ControlEffect
ThresholdHigher values show only the strongest sharp edges
Pre-blurHigher values reduce noise and background texture
AmplifyMakes the overlay more visible
ErosionRemoves small isolated highlight specks
DilationExpands nearby highlight regions

Tips

  • Lower the threshold if too little is highlighted.
  • Raise the threshold if too much of the image is highlighted.
  • Increase pre-blur for noisy high-ISO files.
  • Use the overlay as a guide, not as a final decision.

Last modified June 9, 2026: update (835b35a)