Closed Circuit Television - An Introduction

As the name suggests, Closed Circuit TelevisionThe jump-off point for any CCTV system should be
(CCTV) is a system where in the circuit is closed andthe camera. The camera creates the picture that will
all the elements are directly connected. This is differentbe transmitted to the control position. Aside from
from broadcast television where any receiver that isspecial designs, CCTV cameras are not fitted with a
properly tuned can pick up the signal from thelens. The lens must be provided separately and
airwaves. Directly related in this context includesscrewed into the front of the camera. There is a
systems linked by microwave, infrared beams, etc.standard screw thread for these specific cameras, but
Read on and be familiar with the main componentsthere are different types of lens mounts.
that can go to make up CCTV systems of varyingNot all lenses have focus and iris adjustments. Most
complexity.have iris adjustments while some have very wide
Different Applications for CCTV Systemsangle lenses without a focus ring. The BNC plug is
Probably the most widely known use of CCTV is inused for connecting the coaxial video cable. Line
the world of security. Security systems and suchpowered cameras do not have the mains cable.
applications in retail shops, banks, governmentPower is provided via the coaxial cable.
establishments and the likes. The true scope forThe Monitor
applications is almost never-ending. Some examplesThe image created by the camera needs to be
are:o Monitoring traffic on a bridge.o Recording what isreproduced at the control position. A CCTV monitor is
inside of a baking oven to know the cause ofvirtually the same as a television receiver except that
problems.o A temporary system to carry out a trafficit does not have the tuning circuits.
survey in a town center.o Time lapse recording for theFirst CCTV Systems
animation of plastic puppets.o Used by a stageThe simplest CCTV system is a camera connected
manager of a show to see unnoticed parts of a set.odirectly to a monitor by a coaxial cable with the power
The well-publicised use at football stadiums.o Hidden infor the camera provided from the monitor. This is
buses to manage vandalism.o Recording the birth of acalled the line powered camera. Probably the earliest
lion at a zoo.o Making a wildlife program using a largepopular version of this was the Pye Observation
model helicopter.o Reproducing the infrared vision of aSystem that initiated the concept of CCTV, mainly in
bubble fish!o Aerial photography from a hot airretail establishments. It was an cost-friendly,
balloon.o Production control in a factory.do-it-yourself, self-contained system.
The Camera