Introduction

As the name implies, CCTV is a system in which the circuit is closed and all the elements are directly connected. This is unlike broadcast television where any receiver that is correctly tuned can pick up the signal from the airwaves. Directly connected in this context includes systems linked by microwave, infrared beams, etc.

The starting point for any CCTV system must be the camera. The camera creates the picture that will be transmitted to the control position. Apart from special designs most CCTV cameras are not fitted with a lens. The lens must be provided separately and screwed onto the front of the camera.

The picture created by the camera needs to be reproduced at the control position. A CCTV monitor is virtually the same as a television receiver except that it does not have the tuning circuits.  The picture created by the camera can also be sent to a video time lapse recorder (VTR), a digital recorder, or even viewed via telephone lines or the internet.

CCTV systems may incorporate several different types of cameras such as:  fixed cameras, moveable cameras, hidden cameras, etc.  The type of camera used will depend upon the application.  For instance, if you want to monitor a cash register area in case of robbery, you could use a fixed or hidden camera aimed in the direction of the register to catch a "front view" of the assailant.  The type of lens used will be determined by the distance of the camera from the register and the "field of view" desired..

There are many different ways of configuring a CCTV system.  We recommend that you consult a professional security consultant or security firm to help you with the design of your system.