1. Duplicate Layers:
* Background Layer: Ensure you have a background layer. This is your original image.
* Duplicate Twice: Duplicate the background layer twice. You can do this by right-clicking the layer in the Layers panel and selecting "Duplicate Layer," or by pressing Ctrl+J (Windows) or Cmd+J (Mac) twice.
* Rename Layers: Rename the layers for clarity. A common naming convention is:
* Top Layer: "High Frequency" (or "Texture")
* Middle Layer: "Low Frequency" (or "Color")
* Bottom Layer: "Background"
2. Prepare the Low Frequency Layer (Color/Tone):
* Hide the High Frequency Layer: Click the eye icon next to the "High Frequency" layer to hide it. You only want the "Low Frequency" layer visible and selected.
* Apply a Blur: Go to Filter > Blur > Gaussian Blur. Adjust the Radius setting until the skin imperfections (blemishes, wrinkles) are blurred, but you *still* see some visible texture. Don't over-blur; you want to retain the overall skin shape. The exact Radius will depend on the image resolution. Aim for a setting where most of the small details disappear but the overall contours remain. Usually, a Radius between 2 and 8 pixels is a good starting point. Click "OK."
3. Prepare the High Frequency Layer (Texture/Detail):
* Show the High Frequency Layer: Click the eye icon next to the "High Frequency" layer to make it visible and selected.
* Apply Image Calculation: Go to Image > Apply Image. Here's how to configure the Apply Image settings:
* Source: Select the current Photoshop document and the layer you previously blurred (the "Low Frequency" layer).
* Blending: Choose Subtract.
* Scale: Set to 2.
* Offset: Set to 128. This value is crucial.
* Channel: RGB
* Invert: Unchecked.
* Result: Should be the same as the source doc.
* Click "OK."
* Change Blending Mode: Change the blending mode of the "High Frequency" layer to Linear Light. This will reveal the texture details.
4. Retouching the Low Frequency Layer (Color/Tone):
* Select the Low Frequency Layer: Make sure the "Low Frequency" layer is selected.
* Choose Retouching Tools: Use one of the following tools for smoothing skin and removing color inconsistencies:
* Mixer Brush Tool: (Recommended) Found grouped with the Paint Brush.
* Set the brush settings:
* Wet: 1-10% (Start low and increase if needed. Higher values blend more aggressively.)
* Load: 5-20% (Start low and increase if needed.)
* Mix: 50-90% (Start high and decrease if needed.)
* Flow: 1-10% (Start low and increase if needed. This controls the paint application speed.)
* Sample All Layers: Uncheck this box. You only want to sample from the Low Frequency layer.
* Using the Mixer Brush, gently paint over the skin, blending the tones and removing color imperfections. Work in small strokes, following the contours of the face. Zoom in for precise work. Avoid over-blending, as this can make the skin look unnatural.
* Healing Brush Tool / Spot Healing Brush Tool: Use this for removing blemishes. Sample by holding Alt (Windows) or Option (Mac) and clicking on a clean area of skin near the blemish. Then, click on the blemish to replace it.
* Blur Tool: (Use sparingly) Can be used for very subtle smoothing, but be careful not to over-blur and lose detail. Use a small brush size and low strength.
5. Retouching the High Frequency Layer (Texture/Detail - Optional):
* Select the High Frequency Layer: Make sure the "High Frequency" layer is selected.
* Clone Stamp Tool: (Use sparingly) If needed, use the Clone Stamp tool (set to Current Layer) to remove any large distractions or anomalies in the texture. Be extremely careful not to remove natural skin texture.
* Important: Avoid blurring or smudging on the High Frequency layer, as this will remove important texture. This layer is primarily for preserving detail.
6. Refine (Optional):
* Opacity Adjustment: If the effect is too strong, reduce the opacity of the "High Frequency" layer or "Low Frequency" layer until you achieve a natural-looking result.
* Masking: If you've blurred or smoothed areas you didn't intend to (e.g., eyebrows, eyelashes, lips), add a layer mask to the "Low Frequency" layer. Use a black brush to paint over those areas, revealing the original, unblurred details from the "Background" layer below.
Important Tips and Considerations:
* Work Non-Destructively: Always work on duplicated layers, so you can revert to the original if needed.
* Zoom In and Out: Regularly zoom in and out to assess your work. What looks good at 100% may not look so good when zoomed out.
* Start Subtle: It's easier to add more effect than to take it away.
* Avoid Over-Retouching: The goal is to enhance the portrait, not to create a completely artificial appearance. Retain natural skin texture and avoid making the skin look like plastic.
* Understand Skin Structure: Pay attention to the direction of skin folds and wrinkles and blend accordingly.
* Experiment with Blur Amount: The amount of Gaussian Blur applied to the "Low Frequency" layer depends on the resolution of your image and the amount of smoothing you desire.
* Don't Forget Other Areas: Retouch the neck, shoulders, and any other visible skin.
* Color Grading: After retouching, consider color grading to enhance the overall mood and tone of the portrait.
Troubleshooting:
* Gray/Muddy Skin: Double-check your "Apply Image" settings (Scale, Offset). An incorrect Offset value is the most common cause. Also, excessive blending on the "Low Frequency" layer can contribute.
* Loss of Texture: You may have over-blurred the "Low Frequency" layer. Reduce the Radius of the Gaussian Blur and try again. Avoid blurring anything on the "High Frequency" layer.
* Unnatural Look: You may have over-retouched. Reduce the opacity of the "High Frequency" layer or "Low Frequency" layer, or use a layer mask to reveal the original details.
* Haloing Around Edges: Haloing can occur if you are retouching to aggressively. Make sure to follow the contours of the face.
Frequency separation takes practice. Don't be discouraged if your first attempts aren't perfect. Keep experimenting with the settings and techniques until you achieve the desired results. Good luck!