CCTV is a feature of everyday life thanks to society’s need for increased vigilance. The equipment is also becoming highly affordable, opening up use to individuals as well as businesses. But what exactly is CCTV and is it all the same?
Closed Circuit Television works on a similar principle to actual television. Cameras capture images that can be viewed on monitoring equipment. The big difference is that “closed circuit” means the transmission is limited, and not sent out for public consumption.
CCTV can involve one or more cameras, sending various levels of images, to equipment that can monitor and store the footage.
That’s it in a nutshell, but CCTV comes in various forms. A lot depends on what you need the equipment to achieve. The more sophisticated CCTV equipment provides flexible operation, high-resolution images and digital storage of the output. Some smaller businesses and homeowners are happy with a more basic setup.
Putting CCTV cameras in view
There are many different CCTV cameras available that offer varying levels of quality and movement. Some CCTV systems can even capture audio (sound). Some cameras even have the capability to record clear pictures with poor light. Night vision cameras are often used to keep business premises secure.
The way the images are captured is measured by frames per minute. The more frames per second the camera captures, the higher the resolution of the image. So, most CCTV cameras capture 30 or more frames per second (30fps as its known). This can be important if you need clear, precise images. However, that creates a considerable amount of material to watch and store.
Some more simplistic cameras record only one to six frames per second. These are sufficient to catch a shoplifter for example, as they will be “captured” by the camera in that timeframe.
How CCTV cameras function varies too. Some are static, while others have inbuilt controls that enable the user to remotely pan in to take a closer look at things, or they can be tilted and swivelled to change the view. Other moveable cameras give the user opportunities to remotely move them in a more limited way, for example from left to right.
Connecting CCTV: wireless and wired
How the CCTV camera communicates with the monitoring and storage equipment also varies. Some modern equipment is wireless, and the images can be transmitted that way through walls and other obstacles. Different cameras and equipment can transmit on different frequencies if you need an array of cameras within a particularly large space, such as a town centre or a building complex.
Other CCTV cameras communicate with monitoring and storage equipment via a fixed cable connection. This means the equipment is physically attached. This can work over quite large distances – such as 500ft cables – but the longer the wire to connect it, the more the image resolution decreases, so a higher spec camera may be needed.
Watch and store CCTV footage
The equipment to watch and store CCTV images varies too. Some systems focus more on monitoring what’s going on, so for example a camera in reception to spot someone entering may not need to store the images for more than 24 hours.
Areas of high security, which may need to thoroughly check footage and use it for criminal cases on the other hand, need images to be stored securely, over a set period of time.
It is possible to have a Digital Video Recorder that can be connected to your computer system. This means that images can be shared quickly throughout your network if required.
Digital or tape to store
There are some CCTV systems that still record onto video tapes, though these cause storage problems. Most systems use digital imaging. This means easy digital storage on the monitoring equipment or a computer.
Uses of CCTV
Most equipment these days is purchased for security reasons. Seeing the cameras in place on buildings, and on lampposts around town centres, is a deterrent.
They are also increasingly used for surveillance. Small, discrete CCTV systems have become known as “nanny cams” and are sometimes used by people who want to make sure vulnerable loved ones are being looked after properly.
Smaller, portable CCTV systems are associated with “spying”, to catch people out in wrongdoing or gather evidence for legal action.
