Frequency separation retouching cheatsheet

Frequency separation is a process that gives you independent control over the fine details and the coarse details of an image.

Frequency separation retouching in Photoshop

Duplicate the layer twice. Perform these in each layer:

Lower layer

  • Apply Gaussian Blur

Upper layer

  • Set layer mask to Linear light
  • Image → Apply Image
    • Layer: (select the lower layer)
    • Blending mode: Subtract
    • Scale: 2
    • Offset: 128

Reference