Adjusting the background mask in Adobe Lightroom allows you to refine the areas Lightroom automatically selected, ensuring your edits are applied precisely where you want them. The process involves initially creating the mask and then using various tools to add to or subtract from the masked area.
Creating and Refining Your Background Mask
Based on the provided information, the first step is to generate the initial background mask.
Step 1: Create the Initial Background Mask
To begin, you need to open the image in Lightroom and access the masking tools.
- Open up Lightroom.
- Select the Masking button (usually a circle with a dashed outline).
- Choose the Background option from the list.
As mentioned in the reference, "Lightroom performs some sort of [automatic selection process]". This creates a starting mask based on its analysis of the image.
Step 2: Adjusting the Background Mask
Once Lightroom generates the initial background mask, you will likely need to refine it. Lightroom provides tools to easily modify any mask, including the automatically generated background mask.
Within the Masking panel, under the specific "Background" mask you created, you will see options to Add or Subtract from the mask.
- Add: Use this if Lightroom missed parts of the background you want included in the mask.
- Subtract: Use this if Lightroom included parts of the subject or foreground that should not be part of the background mask.
You can choose from various tools to add or subtract:
| Tool | Description | Use Case |
|---|---|---|
| Brush | Manually paint over areas to add or subtract. | Precise control for intricate edges or details |
| Linear Gradient | Add or subtract a mask that transitions evenly across a straight line. | Adjusting skies, ground, or large areas |
| Radial Gradient | Add or subtract a mask that transitions evenly from the center of an ellipse. | Adjusting vignettes or localized areas |
| Select Subject | Automatically select the main subject to add or subtract from the mask. | Quickly remove the subject from the background |
| Select Sky | Automatically select the sky area. | Add or subtract the sky from the background |
| Range Masks | Refine the mask based on color or luminance values. | Fine-tuning areas based on specific tones/colors |
Process for Adjustment:
- With the "Background" mask selected in the Masking panel.
- Click the Add button or the Subtract button.
- Select the desired tool (e.g., Brush, Select Subject).
- Use the chosen tool directly on the image. For example, if the mask incorrectly includes your subject, click Subtract, choose the Brush tool, and paint over your subject. If it missed some background area, click Add, choose the Brush, and paint over the missed area.
- Repeat steps 2-4 with different tools as needed until the mask perfectly isolates the background.
You can also adjust properties of the mask itself, such as Feathering (softness of the mask edge) or Density (how much the edit is applied), though these are general mask adjustments, not specific to defining the mask boundaries like Add/Subtract tools.
By combining the initial automatic background selection with manual refinement using the Add and Subtract tools, you can create a precise mask for editing your image's background.
