Method 1: Using the Magnetic Lasso Tool (Quick and Dirty)
This method is best for portraits with simpler backgrounds and distinct edges.
1. Open Your Image in Photoshop:
* File > Open > Select your image.
2. Select the Magnetic Lasso Tool:
* Find the Lasso Tool in the Tools panel (it looks like a lasso). If you see the regular Lasso Tool or Polygonal Lasso Tool, click and hold on the icon until a menu pops up. Choose the Magnetic Lasso Tool.
3. Adjust Magnetic Lasso Tool Settings:
* In the Options bar (at the top of your screen), adjust these settings to suit your image:
* Width: Controls how far the tool searches for an edge. Start with something like 5-10 pixels, and adjust as needed. A higher number is good for blurry edges, but too high can grab the wrong edges.
* Contrast: Determines how much contrast the tool looks for. High contrast (e.g., 10-20%) is good for well-defined edges, while low contrast (e.g., 1-5%) is better for softer edges.
* Frequency: How often the tool places anchor points. Higher frequency (e.g., 60-100) creates a more detailed selection.
* Pen Pressure: (If using a graphics tablet) Enables the use of pressure sensitivity to control the width.
4. Start Tracing the Subject:
* Click on the edge of your subject to create the starting point.
* Slowly move your mouse along the edge of the subject. The Magnetic Lasso Tool will automatically try to snap to the edge.
* If it goes off track, you can:
* Click to manually place an anchor point.
* Press the Delete or Backspace key to undo the last anchor point.
5. Close the Selection:
* Once you've traced the entire subject, move the cursor back to the starting point. A small circle will appear next to the cursor.
* Click on the starting point to close the selection. You'll see a dashed line around your subject.
6. Invert the Selection:
* Go to Select > Inverse. This selects everything *except* the subject (i.e., the background).
7. Apply the Blur:
* Go to Filter > Blur > Gaussian Blur.
* Adjust the Radius slider until you achieve the desired level of blur in the background. Start with a low number (e.g., 2-5 pixels) and increase it gradually.
* Click OK.
8. Deselect:
* Go to Select > Deselect (or press Ctrl+D or Cmd+D).
Limitations of this Method:
* Hair: The Magnetic Lasso Tool struggles with fine details like hair. You'll likely get a jagged, unnatural-looking edge.
* Edges: Soft edges and low contrast areas are difficult for the tool to handle accurately.
Method 2: The Better Approach - Using "Select Subject" and "Refine Edge"
This method is much more effective, especially for portraits with complex edges like hair.
1. Open Your Image in Photoshop:
* File > Open > Select your image.
2. Use Select Subject:
* Go to Select > Subject. Photoshop's AI will automatically try to identify the subject in your image. This is usually surprisingly accurate.
3. Refine Edge (Select and Mask):
* Go to Select > Select and Mask. This opens the Select and Mask workspace.
* View Mode: Experiment with different view modes (Overlay, On Black, On White, etc.) to see the selection more clearly. Overlay is usually a good starting point.
* Global Refinements:
* Opacity: Reduce the opacity of the overlay view mode to better see the edge.
* Smooth: Add a small amount of smoothing (e.g., 1-3) to soften jagged edges.
* Feather: Add a small amount of feathering (e.g., 0.5-1 pixel) to blend the edges. Be careful not to overdo it, as too much feathering can make the subject look blurry.
* Contrast: Increase the contrast slightly (e.g., 5-10%) to sharpen the edges.
* Shift Edge: This is crucial.
* Shift Edge towards the *negative* (e.g., -5% to -15%) to contract the selection slightly. This helps remove any haloing effect caused by the blur. Experiment to find the right value. Too much and you'll start cutting into your subject.
* Refine Edge Brush Tool (Hair Brush):
* This tool (the one that looks like a brush with hair on it) is the key to refining hair.
* Select the Refine Edge Brush Tool.
* Paint over the hair areas. The tool will analyze the texture and try to include more of the hair in the selection. Zoom in for better accuracy.
* Output Settings:
* Output To: Choose "New Layer with Layer Mask" from the dropdown. This creates a new layer with a mask based on your selection, preserving the original image.
* Click OK.
4. Invert the Layer Mask:
* In the Layers panel, select the layer mask (the black and white thumbnail next to your subject layer).
* Press Ctrl+I (or Cmd+I on a Mac) to invert the mask. Now, the *background* is selected (masked).
5. Apply the Blur:
* Go to Filter > Blur > Gaussian Blur.
* Adjust the Radius slider until you achieve the desired level of blur in the background.
* Click OK.
6. Optional: Adjust the Mask:
* If you see any areas where the mask isn't perfect (e.g., some blur spilling onto the subject), you can:
* Select the Brush Tool.
* Choose black as your foreground color to *hide* areas (add to the mask, blurring them further).
* Choose white as your foreground color to *reveal* areas (remove from the mask, removing the blur).
* Use a soft brush (0% hardness) for smooth transitions. Reduce the brush opacity for subtle adjustments.
Why the Second Method is Better:
* Accuracy: "Select Subject" and "Refine Edge" are much more accurate than the Magnetic Lasso Tool, especially for complex edges like hair, fur, and foliage.
* Non-Destructive Editing: Using a layer mask allows you to adjust the selection and blur without permanently altering the original image. You can always go back and refine the mask or change the blur amount.
* Hair Detail: The Refine Edge Brush tool specifically addresses the challenge of selecting hair.
Key Tips:
* Zoom In: Work at 100% zoom or higher to see the edges clearly.
* Experiment: Don't be afraid to try different settings in the Options bar and Select and Mask workspace.
* Patience: Refining the edge can take time, especially for challenging images.
* Use Adjustment Layers (Optional): After blurring the background, you might want to use adjustment layers (e.g., Curves, Levels, Color Balance) to fine-tune the color and tone of the background to make it blend seamlessly with the subject.
In summary, while the Magnetic Lasso Tool might seem quick, using "Select Subject" followed by "Select and Mask" (Refine Edge) will give you much better results and more control when blurring the background of a portrait in Photoshop. The time invested in refining the edge is well worth it for a professional-looking result.