High ISO Noise Reduction
In-camera processing that smooths noise in high-sensitivity images before writing the JPEG.
Measured in
levels
In depth
The setting affects JPEGs and video, not raw files, though it is recorded as a metadata suggestion that some converters honour by default. Aggressive settings remove noise and fine detail together, producing the waxy, smeared texture characteristic of over-processed high-ISO images. Raw shooters generally disable it and use better algorithms afterwards.
Examples in practice
An ISO 12800 JPEG at maximum noise reduction shows clean but plastic-looking skin, with all pore detail gone.