Installing CCTV the right way
Today, CCTV systems are common in most areas of our lives. Whether this is a good thing or not is a different story, but it is important that if you are in any way responsible for a CCTV system then you should ensure that it is as good as it can be. Too often we CCTV systems that are obviously a result of a box-ticking exercise – no thought or effort was put into the design and installation. This is a sad thing to see and should not be accepted. You wouldn’t install a lighting system that leaves areas in darkness or create rooms with no doors, so why have CCTV that does not do its job?
This might seem like an odd thing to say, surely if you put CCTV in a room then it is covered – box ticked? Maybe you get lucky, and the camera does provide some good coverage of the area but what is going on in that room, and what actually needs to be covered?
Before making, numbers and types of cameras are discussed every installation should have an operational requirement. This might sound difficult, but this simple document can be used at many stages of the installation and will help make the system as good as it can be.
What should an operational requirement document contain? In its most simple form, the document should detail the overall reason for the CCTV system’s purpose and each area’s specific requirements.
If we take a small ‘corner’ shop as an example we could say the following: the CCTV system’s primary purpose is to reduce theft of stock. This statement may seem obvious, but it is important to have a clear understanding of what the system is trying to achieve – in this case the reduction of theft. So, once you have this established, it is important to work on the elements that could help prevent and detect theft. It is always worth remembering what would be useful for an investigation into an incident. The more cameras you have the more information you will collect and use but if you don’t have the right cameras in the right place you could be missing the vital detail on all of the cameras.
In our shop scenario, overview cameras should be used to monitor and detect theft. This could mean that 5 cameras are used to cover every angle in the store. Usually, overview cameras would be positioned to look down over an area – this generally gives the best results for this requirement. The downside is that you reduce the cameras’ ability to capture good images of the suspect’s face and clothes. This is not a problem as these cameras are doing what you want them to do – capturing evidence. It becomes theft when someone takes an item and walks out of the shop without paying for it. These overview cameras should be able to provide this evidence – ie suspect A takes an item from the shelf and places it in their pocket. To assist an investigation, it is vital that an identifiable image of the suspect is obtained. In our shop example, every entry point should have a camera positioned in such a way that it captures id images of everyone that walks in – in all conditions. If they have a baseball cap on or the sun is setting outside the door – the cameras need to be able to capture their face clearly. This camera should be high resolution, recording at a high resolution and frame rate, positioned lower down, and be able to cope with extreme lighting conditions. This will dramatically increase the likelihood of a positive identification being made. Conversely, overview cameras do not necessarily need to be as highly specified – coverage is more important than the detail. It is worth noting that most cameras have standard-setting that work in most situations. The backlight setting often known as WDR (wide dynamic range) is usually switched off by default. The images captured by a camera that is looking at a door will benefit dramatically with WDR set correctly at certain times of the day and night. If the standard settings are not changed you might see a good image when setting the camera up but when you review footage as the sun is lower in the sky you can only see a silhouette of the person. This attention to detail makes all the difference and separates a good system from a bad one.
In our small shop example, CCTV installed in the right way based on the operational requirement will result in increased usefulness of a CCTV system. Police resource is under huge pressure and if the shop is able to provide stills of the offense and a clear image of the person backed up by the video evidence then it is less likely to be screened out due to lack of evidence. It is unlikely that this will result in a custodial sentence but will likely stop this person stealing from this shop – thus achieving the operational requirement to reduce theft of stock.
The requirement document can also be used as a basis for a tender for a system and a measure of the system’s installed ability to meet the requirement.
