Method 1: Using the Magnetic Lasso Tool (Basic)
1. Open Your Image: Open the portrait image in Photoshop.
2. Select the Magnetic Lasso Tool: In the toolbar, find and select the Magnetic Lasso Tool. (It might be hidden under the Lasso Tool or Polygonal Lasso Tool - click and hold on those tools to reveal the Magnetic Lasso.)
3. Adjust Settings: In the options bar at the top, adjust the Magnetic Lasso Tool settings:
* Width: Start with a value around 5-10 pixels. Adjust it depending on the complexity of the edges of your subject. Higher values "snap" more aggressively to edges.
* Contrast: Controls how much difference in color or brightness is needed for the tool to detect an edge. A value of 10-20% is a good starting point. Higher values require stronger contrast.
* Frequency: How often the tool places anchor points (nodes) along the selection. Start with a value of 50-60. Increase if the selection is erratic.
* Tablet Pressure Controls Size: Leave this unchecked unless you're using a graphics tablet with pressure sensitivity.
4. Start Tracing: Click once on the edge of your subject (the person in the portrait) to start the selection. Move your mouse along the edge. The Magnetic Lasso Tool will attempt to snap to the edge based on contrast.
5. Add Anchor Points Manually: If the tool isn't accurately following the edge, you can click manually to add anchor points. This helps control the selection in tricky areas.
6. Correct Mistakes:
* Backspace/Delete: If you make a mistake, press Backspace (Windows) or Delete (Mac) to remove the last anchor point.
* Click Manually: Force the selection by clicking where you want an anchor point to be.
7. Close the Selection: Carefully trace around the entire subject until you reach the starting point. When your cursor is near the starting point, a small circle will appear next to it. Click to close the selection.
8. Invert the Selection: Go to `Select > Inverse` (or press `Shift + Ctrl + I` / `Shift + Cmd + I`). This selects the background instead of the subject.
9. Apply the Blur:
* Go to `Filter > Blur > Gaussian Blur`.
* Adjust the "Radius" slider to control the amount of blur. A small radius (e.g., 2-5 pixels) will create a subtle blur, while a larger radius will create a more dramatic blur. Experiment until you achieve the desired effect.
* Click "OK."
10. Fine-Tune the Mask (Optional): If the blur seems too harsh around the edges, you can soften the selection edges before blurring. After inverting the selection in step 8, go to `Select > Modify > Feather`. Enter a small feather radius (e.g., 1-3 pixels) and click "OK" before applying the Gaussian Blur.
11. Save Your Work: Go to `File > Save As...` and save the image as a JPEG or PNG file (depending on your needs).
Method 2: Using Layers and Masks (Better for Accuracy and Control)
This method is more advanced but gives you significantly more control and avoids destructive editing.
1. Open Your Image: Open the portrait image in Photoshop.
2. Duplicate the Layer: In the Layers panel (usually on the right), right-click on the background layer and choose "Duplicate Layer."
3. Select the Subject (Using a Better Tool): Instead of the Magnetic Lasso, consider these alternatives for a more accurate selection:
* Select Subject: Go to `Select > Subject`. Photoshop's AI will try to automatically select the subject. This often gives a very good starting point. Then, use the *Select and Mask* workspace (see next step) to refine the selection.
* Quick Selection Tool (W): Brush over the subject. Photoshop tries to find the edges.
* Pen Tool (P): The most precise method. Click to create anchor points and drag to create curves. This takes practice, but gives the best control. After drawing the path, right-click inside the path and choose "Make Selection."
4. Refine the Selection with Select and Mask: After making an initial selection with any of the above tools, click the "Select and Mask..." button in the options bar at the top. This opens a dedicated workspace for refining selections:
* View Mode: Experiment with different view modes (Overlay, On White, On Black) to see your selection clearly.
* Global Refinements:
* Radius: Increase the Radius slightly to soften the edges of the selection.
* Smooth: Smooth out jagged edges.
* Feather: Soften the edge.
* Contrast: Increase the contrast to tighten the selection.
* Shift Edge: Move the selection inward or outward. Use negative values to shrink and cut off messy edges.
* Refine Edge Brush Tool (on the left toolbar): This is the key tool! Brush along the edges of the subject, especially around hair, to improve the selection. The tool analyzes the colors and tries to find a clean edge.
* Output To: Choose "Layer Mask" from the "Output To" dropdown at the bottom right. Click "OK."
5. Invert the Layer Mask (If Needed): If the subject is hidden and the background is visible (the mask will be black where the subject should be visible), click on the layer mask in the Layers panel to select it. Then press `Ctrl + I` / `Cmd + I` to invert the mask.
6. Blur the Background Layer: Select the *duplicated background layer* (the one *without* the mask).
7. Apply Gaussian Blur: Go to `Filter > Blur > Gaussian Blur`. Adjust the radius as desired.
8. Edit the Mask (If Necessary): If you see any halos or imperfections, you can edit the layer mask:
* Select the Mask: Click on the layer mask thumbnail in the Layers panel.
* Use the Brush Tool (B):
* Black: Brush with black to hide areas of the original layer (making the blurred layer visible).
* White: Brush with white to reveal areas of the original layer (hiding the blurred layer).
* Gray: Use shades of gray for partial transparency.
* Adjust Brush Opacity and Flow: Use low opacity and flow values for subtle adjustments.
9. Save Your Work: Save as a Photoshop PSD file to preserve the layers and mask. Save a copy as a JPEG or PNG for sharing.
Why Method 2 is Better
* Non-Destructive: You're not directly modifying the original image. Everything is done on layers and masks, so you can always go back and make changes.
* More Accurate Selections: `Select Subject` and the Select and Mask workspace are powerful tools for creating clean and accurate selections, especially around complex details like hair.
* Flexibility: You can easily adjust the blur amount, edit the mask, or even add other effects to the background without affecting the subject.
* Hair Details: The Refine Edge Brush in the Select and Mask workspace is specifically designed to handle hair.
Tips for Success:
* Start with a High-Quality Image: The better the original image, the easier it will be to make a good selection.
* Zoom In: Zoom in closely to the edges of the subject to make more accurate selections.
* Take Your Time: Don't rush the selection process. Careful and precise selections will result in a more professional-looking result.
* Practice: Practice using the different selection tools to find the ones that work best for you and different types of images.
* Experiment with Blur Radius: The amount of blur needed will vary depending on the image and the desired effect.
* Use a Graphics Tablet (Optional): A graphics tablet can provide more precise control when making selections, especially when using the Pen Tool.
While the Magnetic Lasso is a simple tool, the other methods, especially using `Select Subject` and the *Select and Mask* workspace, will give you far superior results with greater control and flexibility. Good luck!