Night vision cameras (also known as infrared cameras) combine a black and white camera with infrared illuminators for night time surveillance. Even if you use color night vision cameras, they will switch to black and white when used with the IR LEDs at night. This is because black and white cameras produce a better image that color cameras in low light levels. Cameras that are able to switch modes are also called day/night cameras. A built-in light sensor determines when light has changed enough for the camera to operate in night mode and prevents the switching of modes due to a cloud or another temporary object. Infrared illuminators can be purchased separately for cameras that do not come equipped with them.