Achieving high performance images at night is one of the greatest priorities of any video surveillance system.
Achieving high performance images at night is one of the greatest priorities of any video surveillance system. Under the cover of darkness, there is greater risk of crime, but it is also the most difficult condition for cameras to operate in. This is where lighting becomes essential.
Of course, surveillance technology is evolving. Cameras are becoming smarter and more efficient than ever, and lighting needs to adapt to support the latest camera trends. The latest trends in higher megapixel, 4K+, multi-sensor and low-light cameras, along with a greater adoption of video analytics, are fundamentally changing the way we illuminate nighttime scenes.
Broadly speaking, the latest advances in camera technology can be grouped into three main demands on LED lighting — to produce the best surveillance images and system performance at night. These are:
- More powerful illumination
- Intelligent networked illumination
- Reduced cost of illumination
This article will explore the reasons for these three trends in LED lighting, and an emerging fourth trend — improved data for specifiers.
1: The need for more powerful illumination
High MP and 4K+ cameras
Over the last few years, we’ve seen a steady rise in users demanding more detail from their surveillance images at night. High megapixel and multi-sensor cameras are being used to provide evidential detail, not just an overview of a scene. This represents a big leap forward in image quality for the security industry.
But more pixels require more light. High megapixel and 4K cameras need professional lighting to enable the higher resolutions that they are capable of —especially at night. Without dedicated lighting, their performance will degrade back to noisy, lower resolution images. We can see this in the smart phone industry. The latest generation of smart phones, from the iPhone 7 to the Samsung Galaxy S7, settle on a camera sweet spot of around 12 megapixels. Of particular interest is the Samsung Galaxy S6, which boasted 16 megapixels. But the newer S7 model reduced that to 12 megapixels to promote improved low light performance. So always remember, all things being equal, the higher the resolution the more light is needed.
One of the most powerful features of high megapixel cameras is their ability to digitally zoom into an image to extract more details from a scene. But when you zoom, both the high quality pixels and noise in the image is magnified. High megapixel and 4K+ cameras demand more powerful illumination both to improve their overall performance and to empower digital zoom at night.
To respond to the needs of high megapixel cameras, modern illuminators will have to guarantee higher levels of light on scene.
Raytec measures the light output of all of our LED illuminators to calculate maximum distances based on exact light levels on scene — a standard practice followed by most reputable manufacturers. Every Raytec illuminator adheres to the “POWERS standard” and delivers a minimum lighting power of 0.35μW/cm2 (infra-red) and 3 lux (white-light) at its maximum quoted distance; high illumination levels to service high performance cameras. Illuminating any scene to this level will allow the camera to capture highly detailed images and achieve subject identification by empowering digital zoom.
Multi-sensor cameras and large area surveillance
The increased use of multi-sensor cameras also creates a demand for more powerful illumination. With multi-sensor cameras, huge areas can be monitored by stitching together multiple images, so that the end user can deploy fewer cameras to save on installation costs. A multi-sensor megapixel camera can cover the whole scene effectively and its digital zoom enables investigation of areas of interest.
The challenge from a lighting perspective is that huge areas need to be illuminated from a single location — close to the camera. When you are replacing multiple cameras with one camera and one camera location, then multiple illuminators also need to be replaced by one illuminator — not only to cover the whole scene but also to make good financial sense!
So in this instance, the lighting needs to be both powerful and span an incredibly wide area, covering the entire width and depth of the scene. But crucially, it needs to deliver a consistently high level of light throughout the whole area, so that the images are of the best quality wherever they are captured in the scene — near or far. The solution is high power 180° lighting designed to cover the entire camera view. As an example, the latest Raytec Panoramic Ultra products illuminate up to 150 meters at a 180° angle from a single illuminator so that multisensory cameras never miss an event at night. The best solutions should use a highly elliptical beam which shapes the light to match the needs of the camera system. At Raytec, we typically recommend a 180° horizontal x 10° vertical beam for wide angle applications to make sure the full scene is illuminated to its maximum distance without wasting any light — either into the sky as light spill, or onto the foreground as overexposure.
2: Networked intelligent illumination
IP Lighting for Intelligent Systems
The addition of an infra-red illuminator provides even
illumination for a camera to generate high definition black
and white images even in the darkest of nights.
Many of today’s latest camera trends are IP-based. IP video surveillance systems allow end users to monitor their sites and respond dynamically to any event, at any time. When designing lighting for intelligent IP systems, it is important that your lighting provides this same level of control and interactivity.
The latest developments in network illuminators, such as Raytec’s VARIO2 IP PoE series, offer the most flexible solutions for high performance nighttime surveillance. Network illuminators can be operated (a) manually, through a user-friendly GUI that allows operators to respond to real-time events and adjust lighting levels to fine-tune image quality or (b) automatically, responding to alarms or triggers from other devices on the network. Illuminators can also be controlled individually, or a group of illuminators can be controlled together to improve operational efficiency on site. Today, the latest IP lighting for video surveillance can be fully integrated into an IP security system and communicate directly with VMS, BMS, IP cameras or other devices on the network. IP lighting can both trigger and be triggered by any device on the network. IP lighting allows illumination to become smarter and more dynamic than ever before. It can deliver an intelligent, situation-dependent response to achieve the highest levels of safety and security at all times.
For example, there is now no need to set up an illuminator to cover 1 to 100 meters as best it can. Both Infra-Red and White-Light systems can be set to automatically tailor and deliver exactly the right amount of light for the distance at which an event occurs, to get the absolute best images at night. Additionally, the photocell on an IP illuminator, upon detecting darkness, can be used to trigger a camera, or a series of cameras to change into black and white mode — automating and synchronizing the whole security system.
IP lighting can also be programmed to act on alarm. For example, if an intrusion is detected at a perimeter fence line, visible white-light LEDs along that perimeter can be turned on to aid visual inspection, while also acting as a highly visual deterrent to any intruders.
The possibilities are endless, limited only by your imagination. But always remember, a smart system should only use the right amount of light when it is needed to save running costs.