How to Apply Frequency Separation in Photoshop

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Here’s a simplified step-by-step guide to performing frequency separation:

1. Duplicate the Background Layer Twice
Rename the first duplicate “Low Frequency” and the second one “High Frequency.”

Place the High Frequency layer above the Low Frequency layer.

2. Apply a Blur to the Low Frequency Layer
Select the Low Frequency layer.

Use Gaussian Blur (Filter > Blur > Gaussian Blur) and photo retouching service adjust the radius until the textures disappear but the general tones and shapes remain. Typically, a radius between 3 and 10 pixels works well, depending on the image resolution.

3. Create the High Frequency Layer
Select the High Frequency layer.

Go to Image > Apply Image.

Set the Layer to the Low Frequency layer.

Set Blending to Subtract (for 16-bit images, use settings: Scale 2, Offset 128).

Change the layer blend mode to Linear Light.

You’ll now see a normal-looking image again, but the two layers are now separated.

4. Start Retouching
Use the Healing Brush, Clone Stamp, or Lasso Tool with feathering on the Low Frequency layer to smooth out uneven tones.

Work on the High Frequency layer using the Clone Stamp Tool (set to Current Layer only) to fix fine textures like blemishes, wrinkles, or flyaway hairs.

This layered approach gives you total control over retouching and ensures that no part of the image is overly smoothed or distorted.

Common Mistakes to Avoid
Over-blurring the low-frequency layer can make the subject look too flat or artificial.

Editing on the wrong layer can lead to unintended changes in texture or tone.

Skipping feathered selections when using the Lasso Tool can cause visible edges or harsh transitions.

It’s important to zoom in and out regularly to ensure your edits look natural both up close and from a normal viewing distance.

Final Thoughts
Frequency separation is a must-have technique in every retoucher’s toolkit. It offers the flexibility to fix imperfections while preserving a realistic look that clients and audiences appreciate. Although it may seem complex at first, with practice, it becomes a go-to method for high-quality skin retouching and professional photo editing.