Adjustment Brush vs Radial Gradient Mask Explained

Local adjustments in modern photo editing rely heavily on masking to target specific areas of an image without altering the rest of the frame. While both the adjustment brush mask and the radial gradient mask allow editors to apply selective exposure, color, and sharpness tweaks, they serve distinctly different functional purposes. The adjustment brush provides freehand, customizable control for irregular shapes and fine details, whereas the radial gradient mask generates smooth, elliptical transitions ideal for creating directional lighting, vignettes, and broad circular focal points.

The Adjustment Brush Mask

The adjustment brush operates like a traditional digital paintbrush, allowing the editor to manually paint adjustments onto any part of an image.

• Form and Control: It offers completely freeform control. You determine the boundaries of the mask by painting directly onto the canvas using a mouse, trackpad, or pen tablet.
• Core Settings: Most software packages allow you to adjust the brush's Size (diameter), Feather (the softness of the brush edge), Flow (the speed at which the effect builds with each stroke), and Density (the maximum opacity cap of the stroke).
• Best Use Cases: The adjustment brush excels at targeting complex, irregular, or organic shapes. It is ideal for dodging and burning specific facial features, whitening teeth, brightening eyes, cleaning up skin blemishes, or isolating non-geometric subjects like trees, clothing, or architecture.

The Radial Gradient Mask

The radial gradient mask applies adjustments within an elliptical or circular boundary, transitioning smoothly from the center outward (or vice versa).

• Form and Control: It is constrained to geometric shapes—specifically circles and ovals. You click and drag to define the size, angle, and aspect ratio of the ellipse.
• Core Settings: Key controls include Feather (adjusting how abruptly or softly the effect blends into the surrounding image) and Invert (determining whether adjustments apply inside the shape or to the entire area outside of it).
• Best Use Cases: The radial gradient is designed for broad, gradual transitions. It is best used for simulating lighting effects, emphasizing a primary subject by creating a custom off-center vignette, softening background distractions, or accentuating naturally rounded elements such as the sun, light bulbs, or human faces.

Key Differences at a Glance

• Shape Flexibility: The brush mask is completely freeform and unrestricted by geometry. The radial mask is strictly elliptical or circular.
• Speed vs. Precision: Radial gradients can be drawn, stretched, and adjusted in seconds, making them substantially faster for broad enhancements. Brushes require more time and manual effort to trace contours accurately, but they deliver superior edge precision.
• Transition Nature: Radial gradients feature a mathematically uniform falloff from the inner boundary to the outer edge, creating seamless blending across large surfaces. Brush transitions depend entirely on stroke overlap and manual feathering.

In practice, high-end editors often combine both tools. A radial gradient can quickly establish a localized pool of light, while an adjustment brush can be added or subtracted to refine edges and prevent the effect from spilling onto unwanted elements.