The idea
Skin problems come in two kinds: texture (pores, fine lines, blemishes) and tone (blotchy redness, uneven shadow, colour shifts). Frequency separation puts them on separate layers so you can fix one without smearing the other. Blur the skin directly and you destroy texture — which is exactly why over-retouched skin looks like plastic.
Setting it up
- Duplicate the background twice. Name the lower copy Low (tone) and the upper High (texture).
- On Low: Filter → Blur → Gaussian Blur. Raise the radius until texture is gone but the shapes of the face remain — typically 4–10 px on a full-resolution portrait. Note the exact radius.
- On High: Image → Apply Image. For a 16-bit file set Layer to Low, Blending to Subtract, Scale 2, Offset 128. For 8-bit use Blending Add, Scale 2, Offset 0, and tick Invert.
- Set High to blend mode Linear Light. The image should look unchanged.
Working the layers
On the Low layer, use the Lasso with a generous feather and a low-opacity brush or Gaussian Blur to even out colour blotches. Texture is untouched because it lives on the layer above.
On the High layer, use the Healing Brush and Clone Stamp to remove individual blemishes. Set the Clone Stamp sample to Current Layer so it does not pull tone through.
When not to use it
Frequency separation is a repair tool, not a finishing tool. For shaping light and evening out large areas, dodge and burn gives a more natural result and is what high-end beauty retouchers spend most of their time on. Use frequency separation for the specific defects, then move on.
Keep some flaws
The single most common mistake is going too far. Pores, fine lines and a little asymmetry are what make skin read as skin. Reduce distractions rather than erasing them, and check at 100% and fit-to-screen — heavy retouching that looks fine zoomed in often looks waxy at full view.