How CCTV works

Wireless home CCTV systems

Images can be transmitted using analogue or digital technology. Wireless systems can suffer from interference from devices such as routers, cordless phones and microwaves, and can be blocked by heavy masonry or metal objects.

Outdoor home CCTV cameras

If you’re using CCTV cameras outside, make sure they’re weatherproof – an IP (International Protection) rating of 66 is recommended. Wireless cameras are available, but you’ll still have to run a cable to a power source. Position cameras where they can’t be tampered with but can be accessed for maintenance and cleaning.

Indoor home CCTV cameras

Indoor CCTV cameras come in three types: wired, wireless and powerline networked (these plug into your electrical sockets and transmit images to a storage device). Wireless cameras are not recommended inside the home unless the signal can be encrypted, as anyone within range and using a suitable receiver would be able to view the images.

Storing CCTV images

Most home systems use a PC hard drive or standalone digital video recorder (DVR). The main advantage of PC-connected systems is that they often come with software to view the images. Some DVR-based systems have this facility. Make sure that your system allows you to store images in a widely used format, such as Mpeg – otherwise there may be problems if images need to be downloaded and viewed on other systems, such as those used by the police.

Remote access

Some home CCTV systems let you check images over the internet using a PC or smart phone. Other options include email or text notifications when cameras are activated.

Night vision

Monochrome (black and white) CCTV cameras tend to be the most effective in low light, particularly when used with integral infrared illumination – a feature found on some cameras. It’s possible to use CCTV cameras that will film in colour during the day and switch to monochrome when it gets dark.

Home CCTV cameras with motion detection

Some CCTV cameras have a sensor that turns them on when they detect movement. This can be handy if you want to reduce the amount of footage you’re storing.

CCTV footage resolution

High-quality images are needed if CCTV footage is to be used as evidence in court. However, for the best detail a high resolution is required, and this can take up a lot of storage space. The minimum recommended resolution is 352x288 pixels. Also ensure that the date and time used to ‘tag’ images is set accurately.