The Noise Reduction section of the Detail tab has controls for reducing image noise, the extraneous visible artifacts that degrade image quality. Image noise includes luminance (grayscale) noise, which makes an image look grainy, and chroma (color) noise, which is usually visible as colored artifacts in the image. Photos taken with high ISO speeds or less-sophisticated digital cameras can have noticeable noise.

The Luminance control reduces grayscale noise, and the Color control reduces chroma noise. Moving a slider to zero turns off noise reduction.

When making Luminance Smoothing or Color Noise Reduction adjustments, first zoom in on the preview image for a better view.

Moving Luminance Smoothing slider right reduces grayscale noise (above right), and moving Color Noise Reduction slider right reduces chroma noise (below right).