Seeing believes! Closed Circuit Television System (CCTV) provides on-line display of video images on a monitor. Colour or black & white cameras with suitable lenses are used to scan specific areas to be protected or monitored in any premises. Video signals from a camera can be transmitted to a monitor over cables or in a wireless mode. CCTV systems can be designed to scan an area using a single or multiple cameras. In the latter case, images from various cameras can be individually switched on to single monitor. Alternatively multiple camera images can be multiplexed and can be viewed in 4, 8, or 16 frame formats on the same monitor screen.

They can also be mounted on the Scanner Motor & moved around almost 360 degrees for viewing larger areas. The Scanner Motors can also be controlled manually and individual cameras viewed at will. Special zoom lens or wide angle lens are also available for better effects.

Video images can be transferred on to tapes to provide a permanent record. Special recorders which can record from 3 hours to 720 hours on a standard 3 hours tape are used for this purpose, are called TLR -Time Lapse Recorders. There are also intelligent cameras with built in PIR sensors or motion detectors. While guarding the high security areas, these surveillance cameras switch on the recorders, only when any movement is detected, otherwise the recorders are on the “stand-by” mode, thus saving the recording and viewing time.

Recently we also have special add-on cards to be used in the PCs serving as video monitors. These images can also be stored in the hard disk and can also be viewed any where in the world through internet. For night vision, special cameras are available or using infrared lights of sufficient intensity ordinary cameras can be used.