The Auk has a built in light sensor (ILS) for red, green and NIR bands of the spectrum. This value controls the sensitivity of the light measurement. Because the camera may be moving, high sensitivity is not always good. Values lower than 64 should only be used for stationary cameras. 16 is the minimum practical value. In situations where the camera is subject to significant rolling and pitching modtion, values may be set higher. The maximum practical value is 1024.