1. Tutorial Introduction

In daily photography, we often carefully design poses for portrait photos, but after taking the shots, we may notice that pimples and spots on the face are particularly glaring, affecting the overall aesthetic of the image. At this point, using Photoshop (commonly referred to as PS) for skin retouching can effectively solve this issue.

This tutorial focuses on a simplified version of channel calculation skin smoothing specifically designed for PS beginners. Through detailed step-by-step instructions, you'll not only master practical skin retouching techniques but also gain a deeper understanding of PS's basic functions and application logic. I recommend following the tutorial step by step, and with practice, you'll be able to easily enhance your photo quality.

2. Demonstration of Skin Smoothing Results

The final result of this channel-based skin smoothing tutorial will achieve natural softening of skin - preserving the original skin texture and facial feature details (such as eyebrows and eye contours) while significantly reducing blemishes and spots, resulting in more even skin tone and refined visual effects. (Note: The original includes result images, and you can refer to the before-and-after comparison after following the steps in actual application.)

3. Detailed Operation Steps (Including Shortcuts and Parameters)

Below is the complete workflow for simple channel-based skin smoothing in PS, with each step clearly marking key tools, shortcuts, and parameter settings for beginners to follow directly:

Step 1: Import Image and Duplicate Layer

1. Open PS and drag the image you want to retouch directly into the PS workspace to import it.
2. Press the shortcut Ctrl+J to duplicate the current "Background" layer, creating a "Background Copy" layer.
   • Purpose: Duplicating the layer prevents direct modification of the original image. All subsequent operations will be performed on the copied layer, making it easier to backtrack or adjust later.

Step 2: Fix Obvious Flaws with Spot Healing Brush Tool

1. In the PS toolbar on the left, select the "Spot Healing Brush Tool" (icon looks like a cotton swab, you can long-press the "Healing Brush Tool" in the toolbar to switch).
2. Set the parameters in the top options bar:
   • Mode: Select "Normal"
   • Type: Choose "Content-Aware"
   • Brush Size: Adjust to "slightly larger than the blemish/pimple you need to fix" (you can quickly adjust using the "[" and "]" keys on your keyboard).
3. Operation: Place the brush cursor over blemishes or pimples and click the left mouse button. PS will automatically fill the flawed area based on the surrounding skin texture.
   • Important Tip: This is the most time-consuming but critical step in the skin smoothing process! Make sure to thoroughly fix all visible large blemishes and deep pimples. If this step isn't done thoroughly, subsequent steps won't completely eliminate residual flaws.

Step 3: Stamp Layer and Convert to Smart Object

1. Press the shortcut Ctrl+Shift+Alt+E to "stamp visible layers," creating a new layer (default named "Layer 1").
   • Purpose: Stamping combines the effects of all visible layers into a new layer while preserving the original layers, allowing for separate adjustments later.
2. Right-click on "Layer 1" and select "Convert to Smart Object" from the context menu.
   • Purpose: Smart Objects preserve the original layer information, allowing you to modify filter parameters at any time without destructive editing, perfect for beginners who want to make repeated adjustments.

Step 4: Apply "High Pass" Filter (Extracting Contours)

1. Select "Layer 1" and click the top menu "Filter" → "Other" → "High Pass" to open the filter settings window.
2. In the "High Pass" window, adjust the "Radius" parameter to 14.0 pixels. Check "Preview" to see the effect in real-time, then click "OK."
   • Principle: High Pass extracts contour details from the image (such as facial feature edges and hair strands), preparing for subsequent skin softening while preserving details.

Step 5: Stamp Layer and Set Inversion with Blend Mode

1. Press the shortcut Ctrl+Shift+Alt+E again to stamp visible layers, creating "Layer 2."
2. Press Ctrl+I to invert "Layer 2," which will now show a black and white reversed image.
3. In the Layers panel, change "Layer 2's" blend mode from the default "Normal" to "Overlay."
   • Purpose: Overlay mode blends the inverted layer with the layer below, softening skin texture while preserving the contour details extracted by High Pass, preventing the skin from appearing unnaturally "chalky" after retouching.

Step 6: Add Layer Mask for Precise Retouching Control

1. Select "Layer 2" and click the "Add Layer Mask" button at the bottom of the Layers panel (icon with a rectangle containing a circle) to add a white mask to "Layer 2."
2. Open the "Properties" panel (if not visible, access via menu "Window" → "Properties"). Under the "Mask" option, click "Invert" to convert the white mask to a black mask.
   • Principle: A black mask hides the effect of "Layer 2." Later, you can precisely restore the areas that need skin smoothing by painting with a white brush.
3. Set the foreground color to white (press "D" to reset default foreground/background colors, then press "X" to switch the foreground color to white).
4. Select the "Brush Tool" and adjust the brush opacity to 50%-80% (to avoid harsh effects), then gently brush over the facial skin areas.
   • Note: Be sure to avoid areas that don't need retouching, such as eyes, eyebrows, nostrils, and mouth, to prevent blurring these important details.

Step 7: Adjust "Layer 1" and Complete Skin Smoothing

1. In the Layers panel, select "Layer 1" and change its blend mode from the default "Normal" to "Overlay."
2. Click the menu "Filter" → "Other" → "High Pass" again to open the settings window, adjust the "Radius" parameter to 1.0 pixel, and click "OK."
   • Purpose: This low-radius High Pass further refines skin details, making the skin smoothing effect more natural and avoiding an unnatural "plastic" appearance from over-smoothing.
3. At this point, the simple channel-based skin smoothing process is complete. Press Ctrl+S (or "File" → "Save As") to save the processed image (it's recommended to save in PSD format for future modifications, or JPG/PNG formats for daily use).

4. Comparison of Common PS Skin Smoothing Methods

Besides the "Channel Calculation Skin Smoothing (Simplified Version)" taught in this tutorial, there are two other commonly used skin smoothing methods in PS. Beginners can choose based on their needs:

Tip: Although channel calculation skin smoothing involves more steps, it doesn't require plugins and produces results closer to natural skin texture, making it an excellent choice for beginners looking to advance their skills.