What is an IR cut filter?
A. Colour CCTV cameras use a filter mounted on top of the CCD chip which is known as an IR cut filter. The colour cameras use this chip as the spectral response of the CCD chip is quite different to that of the human eye. The filter makes the spectral response closer to that which would be percieved by the human eye. The IR cut filter can affect the sensitivity of the camera at night and therefore True Day and Night cameras have been developed which either have no IR cut filter or a motorised IR cut filter which moves out of the way of the CCD chip at night.
