History

• CCTV, or closed circuit television, was first used in military applications in 1942. Germany used remote cameras connected to black and white monitors to watch V2 rocket launches. The United States military utilized CCTV technology during the development and testing of nuclear weapons, as they allowed for observation from a safe distance. Starting in the 1970s, CCTV became more widespread in nonmilitary use, such as in banks and other retail locations.
  
  

Purpose

• A CCTV system's main purpose is for monitoring a specific location, documenting any illegal or suspicious activity, which can then be shared with law enforcement to identify and capture the suspects. In some cases, the mere presence of a CCTV system helps deter any foul play from occurring. Live monitoring of a situation also gives the added benefit of faster response, as authorities or medical personnel are alerted the moment an emergency occurs.
  
  

Uses

• Despite the obvious advantage of deterring criminals, CCTV systems can also provide an overview of an area to gather information for research purposes. Cities use CCTV to watch high traffic areas, while vehicle checkpoints and toll booths use the technology to capture license plate numbers. Wildlife researchers also use CCTV systems to observe and document animal behavior without interference.
  
  

Equipment

• CCTV systems include a camera, connectors to transmit the signal the camera captures and a recording device. A monitor is also helpful for live viewing of an area. Options are available in each category in order to fit customers' particular needs. Installation varies depending on the size of the area to be monitored and number of cameras used -- a coaxial cable connection typically works better for smaller areas, while a wireless connection helps cover a larger area.
  
  

Camera Types

• Locations requiring CCTV systems vary in many ways, including lighting conditions and size. To accommodate these variables, CCTV cameras are available in color or black and white, fixed focal length or zoom lenses, and indoor or outdoor types. CCTV cameras are also available in fixed mount -- meaning they face in one direction and don't move -- or pan-tilt-zoom, or PTZ, styles.
  
  

System Types

• CCTV camera systems come in two basic types -- analog and digital. The main difference between them lies in how the signal from the camera is recorded. Analog systems use VCRs to record the video signal received from the camera. These are the more affordable of the two system types, but this affordability carries the disadvantage of lower quality images and the need for additional cassette tapes. Digital systems use software to convert the video signal to a digital one, and record this on a hard drive. These types of systems can be connected to a dedicated computer for easier viewing and recording.