Steps:
1. Open the Image in Photoshop:
* Go to File > Open and select the portrait you want to edit.
2. Duplicate the Background Layer:
* This is a crucial non-destructive editing step.
* In the Layers panel (usually located on the right side of the screen), right-click on the "Background" layer.
* Select Duplicate Layer.
* Name the new layer something descriptive, like "Subject Layer". This will help you stay organized.
3. Select the Magnetic Lasso Tool:
* Find the Lasso Tool in the toolbar (usually on the left side).
* Click and hold on the Lasso Tool icon to reveal the different Lasso Tool options.
* Select the Magnetic Lasso Tool.
4. Adjust the Magnetic Lasso Tool Settings (Important):
* In the options bar at the top of the screen, you'll see settings for the Magnetic Lasso Tool. Here's a breakdown of the key settings:
* Width: This controls the area the tool searches for an edge. A higher width means the tool is more sensitive and can snap to edges that are farther away. A lower width is more precise. Start with a value between 5-10 pixels and adjust as needed.
* Contrast: This determines how sensitive the tool is to changes in color or tone. A higher contrast setting will make the tool more likely to stick to sharp edges. Start with a value around 10-20%. If your edges are subtle, lower this value.
* Frequency: This controls how often the tool places fastening points (the little anchors that define the selection). A higher frequency will create a more precise selection, but can also be more demanding on your computer. Start around 50-60 and adjust if the tool isn't following the edges closely enough.
* Tablet Pressure Controls Width: If you're using a graphics tablet, enabling this will allow you to vary the width of the Magnetic Lasso Tool's search area based on the pressure you apply. This gives you more control.
* Feather: Leave this at 0 for now. We'll deal with feathering later if needed.
* Anti-aliasing: Keep this checked. It smooths the edges of the selection.
5. Begin Making the Selection:
* Click once on the edge of your subject to create the starting point of the selection.
* Slowly move the cursor along the edge of the subject you want to select. The Magnetic Lasso Tool will automatically snap to the edge.
* If the Tool Makes a Mistake: Press the Delete (Backspace) key to remove the last fastening point and backtrack. You can then reposition the cursor and continue selecting.
* If the Tool Doesn't Snap: You can manually add fastening points by clicking along the edge where you want the tool to stick. This is helpful for areas with low contrast or blurry edges.
* Zoom In: Use Ctrl + + (Cmd + + on Mac) to zoom in for better precision around tricky areas like hair. Use the Hand Tool (press and hold the spacebar) to move around the zoomed-in image.
* Complete the Selection: When you reach the starting point, click on it to close the selection. You'll see the "marching ants" (the selection outline).
6. Refine the Selection (Crucial Step):
* Go to Select > Select and Mask (or click the "Select and Mask" button in the options bar). This opens the Select and Mask workspace, which is designed for refining selections, especially around hair.
* View Mode: Choose a view mode that helps you see the selection clearly. "Overlay" (press O) is often a good starting point. You can change the overlay color if needed.
* Refine Edge Brush Tool: This is the main tool you'll use in this workspace. Select it from the toolbar on the left (it looks like a paintbrush with a cursor).
* Brush Size: Adjust the brush size in the options bar at the top. Use a smaller brush for details and a larger brush for wider areas.
* Brush Over the Edges (Hair!): Carefully brush over the edges of the subject, especially around the hair. The tool will attempt to separate the foreground (subject) from the background. You might need to experiment with different brush sizes and pressure.
* Global Refinements (Right Panel): In the properties panel on the right, you can further refine the selection:
* Smooth: Adds smoothness to the selection edge (helpful for reducing jaggedness).
* Feather: Blurs the selection edge (add a small amount, like 0.5-1 pixel, for a more natural look).
* Contrast: Increases the contrast between the selected and unselected areas (can help sharpen the edge).
* Shift Edge: Moves the selection edge inwards or outwards. This can be useful to correct minor issues. Generally, you'll want to shift it inward slightly (-1 to -3 pixels) to avoid having any of the background color creeping into your subject.
* Decontaminate Colors: This is important, especially around hair. It helps to remove color bleeding from the background into the subject. Make sure this is checked.
* Output Settings: At the bottom of the properties panel, set the Output To: dropdown to New Layer with Layer Mask. This is a non-destructive way to keep your original image intact.
* Click OK to exit the Select and Mask workspace.
7. Apply the Blur:
* You now have a new layer with a layer mask, isolating your subject. Select the *Layer* (not the mask) in the new layer you created.
* Go to Filter > Blur > Gaussian Blur.
* In the Gaussian Blur dialog box, adjust the Radius slider until you achieve the desired level of background blur. A higher radius means more blur. Start with a low value and increase it gradually. Pay attention to how the blur looks around the edges of your subject.
* Click OK.
8. Optional: Adjust the Blur Strength:
* If the blur is too strong or too weak, you can adjust it by going back to Filter > Blur > Gaussian Blur.
9. Save Your Work:
* Go to File > Save As and save your image as a Photoshop (.PSD) file to preserve the layers. This allows you to edit the image later.
* To save a flattened version for sharing, go to File > Save As and choose a format like JPEG (.JPG) or PNG (.PNG).
Tips and Troubleshooting:
* Practice makes perfect: The Magnetic Lasso Tool and Select and Mask workspace can take some getting used to. Don't be discouraged if your first attempts aren't perfect.
* Use the right tool for the job: For complex selections (like very fine hair or difficult edges), consider using the Pen Tool or Channels for more precise control.
* Zoom in and out frequently: This helps you see the overall effect and identify areas that need refinement.
* Experiment with the settings: The optimal settings for the Magnetic Lasso Tool and Select and Mask workspace will vary depending on the image.
* Non-Destructive Editing is Key: Always duplicate your background layer and use layer masks. This allows you to make changes without permanently altering your original image.
* If the subject is being partially blurred: This usually indicates that the layer mask isn't perfectly aligned with the subject. Go back to the layer mask and use the Brush Tool (with black or white) to paint over the areas that need to be corrected. Black hides, and white reveals. Make sure you have the layer mask selected, not the layer itself. (Click on the mask icon next to the layer thumbnail to select it.)
* Performance issues: If Photoshop is running slowly, especially when using the Select and Mask workspace, try closing other applications, increasing the amount of memory allocated to Photoshop, or working on a smaller version of the image.
By following these steps, you can effectively blur the background of a portrait in Photoshop using the Magnetic Lasso Tool and Select and Mask workspace, creating a professional-looking result. Remember to be patient and experiment with the settings to achieve the desired outcome. Good luck!