Abstract: A surveillance system that monitors video signals (composite or s-video) from surveillance cameras to detect a degradation of the ambient lighting sources in and around public and private areas. The system also monitors for the black level of a video signal from a surveillance camera that is created by situations such as the covering of an operating camera or spray paint put on camera lenses by vandals. The system also monitors for loss of video that may be caused by loss of power, vandals damaging cameras, or cutting video cables. The surveillance system as a whole can be used with existing video equipment to monitor and detect programmed levels of the previous described situations and to supply alarm signals to an existing alarm station or to a remote alarm station.