Installing the correct CCTV camera in 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 see 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, but 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 the make of the camera, numbers and types of cameras are discussed; every installation should have a document of 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 simplest form, the document should detail the overall reason for the CCTV system and each surveillance 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 the 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 perhaps 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 only 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 – i.e. suspect A takes an item from the shelf, places it in their pocket, and walks out of the shop. To assist an investigation, it is vital that an identifiable image of the suspect is obtained.
In our shop example, every entry and exit point should have a camera positioned in such a way that it captures images of everyone that walks in and out – 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 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 detail. It is worth noting that most cameras have standard settings 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 from 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 the 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 the increased usefulness of a CCTV system. Police resources are 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 it will likely stop this person from stealing from this shop, thus achieving the operational requirement to reduce the theft of stock.
The operational 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.
