A system and method that provides adaptive IR illumination for a camera. In some implementations, IR illumination adapts to the objects in a scene being monitored and IR illumination adaptation may be implemented in conjunction with automatic exposure and other exposure adjustment methods. Some implementations include: illuminating a scene using a first IR illumination power; capturing a first image of the scene with a camera; and determining whether a first region of the first image is underexposed or overexposed. When the first region is underexposed, the scene is illuminated at a second power level greater than the first illumination power and a second image is captured. When the first region is overexposed, the scene is illuminated at a third power level that is less than the first illumination power and a third image is captured. The operations are repeated until scene illumination is satisfactory.