Many specifications in a camera use 'IR' but what is this? IR stands for Infra-red Light. This light is invisible to the eye. It has low frequency and wavelengths longer than 700 nm. It is used in CCTV cameras to record images in the dark. The camera emits this light and records the reflected light determining the distance at which an object is. Normally, a camera operates on normal colour during the day when there is sufficient light, but at night or when there is low light, the IR sensitivity needs to be high.