Security in today’s world is defined by light. Yes, that CCTV camera you passed on your way home from work, that License Plate Recognition Camera at the car park, that facial recognition system in the airport or any camera for that matter – they all need light to work well – fact. Without light, there is no image. Without the right/good light, there is no good image. But not all light is the same, and it is the quantity, quality and distribution of light that governs image quality. Light is indispensable to security cameras and good lighting determines whether the captured images will stand up to intense scrutiny and deliver the required results. Sure, all cameras deliver good images during the day – easy. But most crime occurs at night and it is the night time performance of your camera which should most interest you and when good lighting really counts and can make the difference.
Types of CCTV illumination – Infra-Red and White-Light
Typically, visible White-Light can be used to provide colour CCTV images in hours of darkness; it also provides additional safety for personnel and deterrence for intruders. Infra-Red light on the other hand allows covert capture of night-time images, with zero light pollution. White-light is visible to the human eye, while Infra-red is invisible but still detectable by CCTV cameras. Both visible light and invisible light can enhance the safety and security of any system.
Dedicated for CCTV
LEDs are now established as the technology of choice in many industries as a result of their inherent energy efficiency, reliability and high performance. This, together with their unmatched levels of control and flexibility makes LEDs ideal in meeting the demanding requirements of professional CCTV installations globally, and they have quickly become the preferred lighting solution in the security industry.
But what is dedicated CCTV lighting and why is it so important for cameras? Dedicated CCTV lighting is largely designed around lighting and camera alignment and set-up; this is crucial to achieve the best CCTV images at night and the highest level of security.
Cameras, like our eyes rely on light reflected from objects in the scene to produce an image. Light determines whether a subject can be viewed at all, at what distances, and the quality and direction of the light controls the appearance of the subject. It’s not as simple as choosing between White-Light or Infra-Red illumination for security systems. And the quality of images captured by CCTV cameras does not solely depend on the components of the camera and lens.
It is important that lighting for CCTV is positioned adjacent to the camera with the light output angle matched to the camera’s field of view. Camera alignment and set-up is crucial for achieving excellent CCTV images at night and optimum security. And since LED lighting produces a highly targeted beam pattern that can be easily manipulated to match a camera’s field of view, it can meet the needs of any camera; unlike traditional flood luminaires that emit light in a 360 degree sphere, and spill light at all angles including where it is not needed.
When illumination is matched to the view of the camera, it targets the light exactly where it is needed, suffusing each pixel on a sensor in a camera with light. The result is an evenly illuminated scene with no dark areas or bright spots and a higher level of image detail and good facial recognition. By not spilling light out of the required area, security systems also become more eco-friendly.
As such, LED technology is more capable of capturing images that are rich in detail, which would stand up to the strictest degrees of scrutiny.
There is also another consideration to bear in mind – and that is the colour of light.
To achieve premium quality images with colour CCTV cameras, the light needs to be closely matched to the colour of daylight – enabling better visual accuracy to produce more lifelike and detailed results when used in CCTV applications. Cool White-Light LED luminaires have excellent colour representation and tend to have a colour temperature of 5,000-6,000K which is most similar to the colour of daylight. Our eyes naturally respond best to this for viewing CCTV images. Traditional street-lights or other ambient lighting, due to their all-familiar orange/yellow glow and uncontrolled light beams, often lead to lower levels of detail in CCTV images.
The positioning, angle and type of light all have significant implications on the quality of the surveillance images, and ultimately the level of security.
Quantity and Quality
Another factor which influences the quality of images is the quality of the light output itself. Quality of light is generally evaluated in terms of – Total Light Output (power) of the luminaire and Light Distribution i.e. where and how evenly the light is distributed.
Total Light Output gives a quantitative measure of the total useable energy emitted from an illuminator. It is a quantitative measure – but does not give any indication of the distribution of the light which, together with total power, governs the quality of illumination.
Light Distribution refers to the measurement of the amount of light at a number of specific points which ascertains the quality of the beam pattern. Certified laboratories use photometric testing to measure the light at regular increments at 360 degrees, creating a 3D plot to accurately profile the beam pattern.
But why are these two factors worth considering? And how do they affect image quality?
Measuring light power on a scene gives an indication of how much light is capable of being reflected back into your camera lens and also the maximum light distance that can be achieved – this is crucial when it comes to calculating sufficient illumination for your camera, thus governing image quality.
Light distribution data is equally important for understanding the exact spread of illumination from your luminaire, i.e. the exact beam angle – both horizontally and vertically and also how far the beam extends. It is also very important for knowing the exact lux level (amount of light) at any given point of the beam.
Lighting designers are able to load this data into industry standard design packages (such as Relux or Reality) to enable them to undertake comprehensive and highly accurate lighting designs, plotting illumination on site to precisely match camera requirements for optimum performance.
Light affects everything! From the very early stages of conceptualising security for any given site, right to the very end when high quality image capture is critical – light plays a central role. Understanding the behaviour of light and its relationships with the natural as well as built-environment can truly provide security of the highest standards. Correctly designed lighting not only delivers improved images but can also save running-costs for users which simultaneously minimises environmental impact.
To a certain extent the fast pace of technological development has created knowledge gaps which have a significant impact on the security of any location. Claims of super light sensitive cameras not needing light, or thermal cameras that are sometimes touted as replacements for dedicated CCTV lighting, and street-lighting that is often deemed to be sufficient for surveillance purposes. However in most cases, dedicated CCTV lighting designed specifically to enhance security, far outperforms lighting designed for a different purpose.
Light is the key to our safety and security and it is the responsibility of everyone, from design/architectural professionals and engineers, to the user/owner of a building with CCTV, to ask the question – What about the lighting?
Furthermore, with the Internet permeating many aspects of security systems today, and with the recent development of IP addressable luminaires, it is now possible and often considered the best approach to integrate lighting and all components of a security system over a network infrastructure. By fully integrating lighting into a network security system it facilitates seamless communication with all other security network devices on site, and can offer instant lighting response to events and intrusions on site, triggered automatically by camera motion detection for example, creating the highest possible level of security and crime prevention. The most advanced IP addressable luminaires powered through PoE now offer various control options to easily communicate with all devices on site including: full integration into video or building management systems, control through simple HTTP commands, or even direct communication via an app embedded in the camera itself. With such flexibility, it is now even easier to have total control over your lighting at all times, and use it in a smart way to create the most advanced and proactively responsive security system at night.
This advanced lighting approach designed specifically for surveillance systems highly differentiates dedicated CCTV lighting from lighting meant for an entirely different purpose that is often wrongly considered ‘enough’ for cameras – e.g. street lighting, building lighting.
Lighting forever continues its journey to becoming even smarter. With advances in technology in general and the security industry in particular, lighting is being revealed to have as much importance in the security industry as it already has in other industries such as the cinematic and photographic industries, who know and embrace the fact that … no light = no picture.
So the next time you see a CCTV camera will you wonder if it has proper lighting?
I always do.
Tony Whiting is Managing Director (Joint) of world leading CCTV lighting manufacturing company Raytec Ltd. He has over 25 years’ experience developing innovative solutions for the CCTV and general area lighting market.
Tony’s strong entrepreneurial background spans over two decades in directorship roles, founding both Raytec and previously Derwent Systems.
Tony’s expertise and passion is smart and efficient LED lighting systems.
As leader of Raytec’s strategic and research and development teams, Tony instils a wealth of training and technical guidance, and has a strong history of designing ground-breaking products, including the industry’s first IP addressable range of CCTV lighting.