By: Wayne Connors
Millions of people throughout the UK rely on CCTV cameras for the protection of their property, for the physical protection of their families, or for the protection of their businesses. Night vision CCTV cameras are the only ones that can guarantee a certain level of protection 24/7, which makes them very popular.
But, as in any other field of the tech industry, competition leads not only to better performance in general, but also to a proliferation of features and technologies. Night vision CCTV cameras are no exception.
Manufacturers, service providers and security consultants can, upon command, produce a seemingly never-ending litany of technical parameters and standards that sound very important and relevant. But – just as with anything else, from cars to computers – not all of them are equally important to everyone.
So how do you choose the best night vision camera? What parameters of a night vision security camera are relevant for your property, or for your business?
If you just pick the camera that ticks all the checkboxes, has the most features, lists the best parameters and so on, you’ll just end up buying the most expensive one. And, since many parameters are, in fact, correlated, you may end up buying a camera that gets everything right except for one thing that you really need. A one-size-fits-all is just as bad when choosing security devices as when choosing a suit.
What Do I Need This Night Vision CCTV Camera For?
The first and only question that you want to ask yourself when choosing a night vision CCTV camera is “what do I need it for”. If you can articulate the answer to that question, everything else will just fall right into place.
Specifically, what you want to know is:
- What area does the camera need to monitor – i.e. what location does it need to monitor, and how big an area?
- What kind of threats are you looking to guard against?
- How will you be using the recordings?
These three elements determine all the relevant parameters of a CCTV camera.
What area the camera needs to monitor will determine all relevant installation parameters – indoor vs. outdoor installation, connectivity, range – and will tell if you need any approvals from public authorities.
What kind of threats you are looking to guard against and how you will be using the recordings will help you determine a whole lot of other parameters related to image quality, software and image processing capabilities, and so on.
Indoor vs. Outdoor Night-Time Cameras
Let’s start with the most basic differentiating feature: where a camera is installed.
There is no fundamental difference in terms of imaging technology or inner workings between an outdoor CCTV camera and an indoor one. However, outdoor night vision cameras have their housings and electronics designed so as to withstand a harsher environment than those designed for indoors use.
All CCTV cameras have specific ratings, but these are particularly more relevant for outdoors cameras. Ratings are given two-digit names, such as IP65 or IP66. The first rates protection against dust and solid objects, and the second one refers to protection against liquids. The minimum rating you should consider for an outdoors camera is IP65, but a higher rating colour– IP66 or IP67 – is recommended for harsh weather. Ratings above that are reserved for cameras that can be immersed in liquids, which you are very unlikely to need.
Why would you want to install a camera in an outdoors environment? The most obvious reason, of course, is that you have to monitor a large outdoors area, such as a parking area or a large yard. But even small areas, like a porch or a small yard, often need to be monitored using outdoors CCTV cameras. That’s because, for reasons that we will discuss shortly, you cannot aim night vision CCTV cameras at windows.
Black and White vs. Colour Night Vision CCTV Cameras
For the longest time, night vision CCTV cameras have been associated with that grainy, black-and-white footage that you can sort of make out, but not too well. For a few years now, though, manufacturers have been offering colour night vision CCTV cameras, but black-and-white night vision cameras are still selling.
How come – and which one’s better?
To figure that out, let’s start with the basics: how can CCTV cameras “see” in the dark?
When you’re in a dark room, the easiest way to see what’s in a corner of a room is to shine a flashlight on it. That works with CCTV cameras, too, but shining a strong floodlight at the area you want to monitor is not a practical option.
So CCTV manufacturers came up with a good trick: night vision security cameras have an array of LEDs, which they use to illuminate the area they monitor – but the LEDs emit infrared (IR) light. Your eyes can’t see it, but the sensors in the CCTV cameras can.
This is also why you cannot aim them at windows: if you do, all they will record is the reflection of their own lights.
However, just like everything seems to be blue when you shine a blue light on it, objects just appear to be different shades of infra-red if you shine an IR light on them. The camera firmware “translates” that to black-and-white, so that you can see it, but that’s all.
Colour night vision CCTV cameras have a special type of sensor which allows them to work in low-light environments. Most urban areas do have some ambient light, even at night.
Imaging sensors designed specifically for such an environment can therefore show a clear enough picture even at night. This can be relevant: it allows you to capture things like the colour of vehicles or items of clothing, which can help identify vehicles or intruders.
Colour night vision CCTV cameras tend to be more expensive, but they do offer better image quality and can offer more details. On the other hand, they do need some amount of ambient light, which limits their usefulness outside urban and suburban areas, and their range is limited. Black and white CCTV cameras tend to be cheaper, and are a better option if you need to monitor wide areas or distant objects.
Night Vision vs. Day/Night CCTV Cameras
True day/night CCTV cameras have imaging sensors that can register both IR and visible light. During the day, the IR component of the spectrum is eliminated using an IR cut filter.
This enables them to compensate not only for low ambient light conditions, but also for variable ambient light. In other words, their firmware can adjust the image so that you get a clear picture both during the day and during the night.
Day/night CCTV cameras are particularly useful for monitoring locations that need 24/7 surveillance, since they can provide clear footage throughout the day.
A variety of optical parameters – at the most basic level, the focal length – determine the range that a CCTV camera can cover. The rule of thumb about it is simple: a higher focal length means a camera can focus on objects that are further away, but it also means it covers a narrower area. In other words, it can cover a greater distance, but its field of vision is narrower.
Many night vision security cameras will explicitly list the maximum distance they can cover. This is particularly relevant for day/night CCTV cameras, because the maximum distance that they can cover is not determined only by their optical parameters, but also by the intensity of their IR light and the sensitivity of their imaging sensors.
When talking about a CCTV camera’s image quality, we tend to lump together several factors, such as resolution and sharpness. Some of these parameters are correlated, but in surprising ways!
Image resolution is the most obvious aspect. The higher a camera’s resolution is, the more details it can capture in a well-focused image.
1080p (2 MP) cameras are generally sufficient for most scenarios, but higher-resolution cameras – 4K or higher – may be useful if you need detailed surveillance over a wider area or at high distances. However, it’s worth remembering that a higher image resolution also results in higher storage requirements!
How sharp an image is depends not only on the camera’s resolution, though, The minimum and maximum distance at which a camera can provide a sharp, focused image depends on a variety of optical parameters, in addition to the sheer quality of the lens(es) and imaging sensors. Consequently, you want to pay attention to optical specifications as well as resolution.
Power and Connectivity
We are so used to seeing CCTV cameras everywhere that we tend to think of them as these tiny electronic islands of sorts, but in truth, they aren’t. Like all electronic devices, they need electrical power to work – and they need to transmit their pictures somehow. In fact, this is their giveaway. If you were wondering how to spot night vision cameras, this is it. Look for the power source.
Most CCTV cameras today are IP cameras, which means they plug into a computer network. Unsurprisingly, then, night vision CCTV cameras come in wired or wireless options.
Wired connections are cheap and high-capacity, which means that they are particularly useful for cameras that need to send high-resolution pictures or cameras that need to be very cheap. On the other hand, you have to run a data cable to them. That means extra maintenance and installation effort, not to mention a cable that an intruder can simply cut if it’s exposed.
Wireless cameras do away with the data cable, which makes them convenient to install and operate. However, their range is limited to the access point’s range. Nowadays, Wi-Fi networks are fast enough that you can stream high-resolution images over a quality connection – which is to say that wireless cameras are not a good option in areas where you can’t rely on a strong Wi-Fi signal.
Many Wi-Fi cameras are battery-powered, so that they are, indeed, truly cable-free. At the other end of the spectrum, many wired cameras use a technology called Power over Ethernet (PoE), which enables them to use the same cable for both power and data connectivity.
Connectivity doesn’t directly influence a CCTV camera’s night vision capabilities, but it does influence deployment options, which can be relevant for nigh-time surveillance. For example, wireless cameras are easier to deploy along fences than their wired counterparts.
Night Vision CCTV Installation Constraints
Like all CCTV cameras, security cameras with night vision features are subject to a few installation constraints. They cannot see around corners, for example, and they can only cover a limited area.
CCTV cameras for 24/7 or night-time surveillance pose some additional, specific installation constraints. We’ve already hinted at some of them: they have to be installed away from windows, the maximum distance depends on optical as well as illumination parameters, and some cameras, such as colour night vision cameras, may require a specific level of ambient light.
However, many other additional constraints come into play. For example, CCTV cameras installed in areas with heavy vehicle traffic have to cope with quick variations in lighting conditions caused by the headlights of passing cars. Some cameras are designed to be particularly good at coping with these situations and have a high dynamic range, but even these have to be installed so that they cannot be easily “blinded” by simply parking a car in front of them.
Feel like all this is too complicated? It can be! At ACCL, we have spent the past two decades finding and installing the best night vision security cameras in London and the surrounding areas. Our partners – Assa Abloy, Avaya, Honeywell, and Paxton help us make sure that our clients always have access to the best night vision CCTV cameras in the UK. And we tackle flawless CCTV installation.