CCTV: An Introduction To CCTV

What is CCTV?

An installation of directly connected components creates a circuit known as Closed Circuit Television (CCTV), which is invisible to anyone outside the circuit.

This is different from a terrestrial television broadcast system, which anybody with an antenna and reception equipment can view.

Who needs a CCTV system?

Nowadays, CCTV systems are ubiquitous. Given the increased level of security they provide, CCTV systems are no longer considered expensive luxury items.

Both the private and commercial sectors use CCTV systems for security and crime prevention, as well as to protect the public's health and safety.

You have likely observed CCTV systems in operation in various locations such as town centers, football stadiums, high street shops, sports centers, petrol stations, and public transport.

A CCTV system is a proven method of increasing the level of security on your premises. Its visual appearance alone will deter a criminal from approaching or entering your property for fear of being captured and identified on the system.

Individual requirements can tailor-make CCTV solutions. They can be as simple as one camera and a monitor, but it is quite common to have multiple cameras/monitors and recording devices in one installation.

The components of a CCTV system

There are three basic elements to a CCTV system:

1. Camera
2. Lens
3. Monitor unit

The camera is the element that captures the image and transmits it back to the monitor. The camera needs a lens to be able to focus on the subject. There are a wide variety of lenses available to suit different applications.

The monitor is the receiver unit that converts the captured image into a picture, allowing you to see it.

Color or monochrome?

This is a common question, but ultimately, it's up to you to decide.

Your property's environment and your needs should inform the design of your CCTV system. The installing company should provide guidance on the suitability of different options, features, and benefits, including color and monochrome units. It may be that you need a camera that will work in color during the day and automatically switch to monochrome at night!

Recording

As circumstances don’t normally permit the luxury of having a dedicated person sit and watch a monitor 24 hours a day, the image captured by the camera needs to be recorded so that it can be viewed later if necessary.

Traditionally, this was done with a time-lapse video cassette recorder (VCR), which worked on the same principle as a domestic video but with the ability to record for a much longer period of time.

However, the digital hard disk recorder (HDR) has now supplanted the VCR. Rather than using tapes, the HDR stores the images on a hard disk drive similar to the way a home computer stores data.

More than one camera?!

Most systems today consist of multiple cameras, but you don't need a monitor and recorder for each camera.

You can use equipment that splits the monitor into four separate screens, each displaying four cameras, or you can use a four-way sequence unit to select the camera you want to view. Alternatively, you can use the automatic mode, which will cycle through the four connected cameras.

However, the most common way of controlling multiple cameras is via a multiplexer.

Simultaneously, a multiplexer not only integrates the previously mentioned features, but also enables the individual coding of each image from each camera, thereby enabling the recording of all cameras on a system onto a single tape or hard drive unit. The multiplexer then uses these code marks to play back the recorded picture from the camera that you wish to view.

Historically, multiplexers and recording units were separate pieces of equipment, but recently a number of manufacturers have developed units that do both jobs.

I want…… I need…....

These days, you can design a CCTV system to fit any scenario you can think of using options from the vast range of equipment available from manufacturers worldwide.

For example, cameras can be internal, external, highly visible, or covert. They can be static or fully controllable/movable from a remote location. Have one camera or hundreds; record for one or 21 days. With a suitable internet connection, you can even view your property when you are abroad.
Get the picture??!!!

Quality Counts

While an enthusiastic do-it-yourselfer can purchase equipment purporting to be a CCTV system from their local store, and electrical companies have also joined the CCTV trend by installing systems, it is always recommended to consult a specialist company.

Why?

Approximately 70% of cases result in the inadmissibility of CCTV footage as evidence in a court of law due to its inadequate quality. This can result from the poor design and inadequate installation of the system and highlights the importance of seeking professional advice from the outset.

You should only approach a specialist company that is professional in their approach and can demonstrate experience in design and installation. Most importantly, you must feel confident that the company you choose will listen to and understand your individual CCTV requirements. Their experience with lens optics and camera technology will guarantee you satisfaction with your system.

A specialist company will ensure the best value for money, for example, by using different lens or camera mounting positions, which can not only monitor the area at risk but also give an outline view of the surrounding area at the same time.

Data protection

The Data Protection Act of 1998 requires the registration of a CCTV system.

Since 24 October 2001, it has been a criminal offense to have an unregistered CCTV system that records people in a public or a private place (conditions apply).

To ensure compliance with the Data Protection Act 1998, the Code of Practice contains legally enforceable "standards."

In addition to the Standards, there are another 30 points of good working practice that, when applied, aim to uphold public trust in CCTV systems and guarantee that installers and users adhere to the law.

The Code of Practice is available for you to view at www.dataprotection.gov.uk.