Sensor calibration, also known as black shading, is a process during which the camera optimizes image quality by ensuring that pixel sensitivity remains consistent throughout the sensor. Calibrating the sensor generates a calibration map based on system and environment settings. After calibration, the sensor shows a uniform noise profile over the whole area without any falloffs on any side.
Different RED cameras offer different sensor calibration methods. For example, cameras in the DSMC2 family offer sensor calibration via both Manual Calibration and Auto Calibration.
For more information, download the corresponding Operation Guide for your camera.