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 also have this facility.  Make sure 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. In addition, make sure that if you get a camera that can record high-quality images, the PC or DVR is able to record them. Remote access Some home CCTV systems, such as IP ones, let you check images over the internet using a PC or smartphone. 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. 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.