Charge of the light brigade

Security systems that use excessive amounts of bright light will face restrictions under new legislation coming into force next year. Companies could be fined up to £20,000 if they fail to comply with local authority abatement orders issued following complaints about the nuisance caused by lights on their premises.

Industry experts warn that designers, specifiers, installers and owners will need to choose their security systems more carefully than ever before and be aware of the latest technology for minimising intrusion.

The Clean Neighbourhoods and Environment Act received Royal Assent on 7 April 2005, and most of its measures are expected to come into force in April 2006. Light pollution will for the first time be treated as a ‘statutory nuisance’.

This opens the way for local authorities to take tougher action than has been available to date. They will be able to issue an abatement notice after investigating a complaint and can prosecute if this is ignored. But advances in recent years mean that the technology now exists to provide effective CCTV without contributing to light pollution, says Vista brand director Andrew Pigram. The new Act will accelerate the adoption of infrared lighting, he believes, particularly in conjunction with latest cameras and lenses that are optimised to give high performance both in daylight and at night. "Security is being raised by the government as one of the biggest culprits of light pollution," says Derwent marketing director Shaun Cutler. "I think the industry could react positively and professionally to the Act."

The introduction will particularly affect businesses that have security systems that flood areas near housing with bright white light. Exclusions will, however, apply where the lighting is needed primarily as a safety measure, for instance in stations and goods vehicle operating centres. "Companies often over-react by illuminating all of the grounds around their properties instead of using very tight lighting around the building," says Norbain technical training manager Ian Fowler. These are the kinds of systems that will need to be re-fitted, he predicts. Modern cameras can operate in far lower light levels than their predecessors, though less advanced cameras may not work well in darker conditions. "The cheap fix used by many sites has been to provide extra lighting instead of changing the cameras," says Buro Happold security consultant Bob Holmwood. "The act will have a major impact on these sites."

Pros and cons

Bewator Video Product Division general manager Mark Wherrett believes there may be pros and cons to each solution. "It is an education for installers, and also for customers – they have to understand some of these issues. People will have to think what is best for the application so that it works effectively."

A lot of energy is wasted lighting up areas that don't really need to be lit up, says Shaun Cutler. Measures to cut down on the amount of light include the use of detectors to trigger lighting and the adoption of infrared light to enable CCTV systems to see at night. "So rather than flood an area with visible illumination, you can use invisible illumination – infrared – where the camera can still see, but there is no light pollution," he says.

Once a local authority receives a complaint, it will generally ask the complainant to keep a diary. An inspection will then take place if it appears that a nuisance has been committed. Inspectors will base their judgement on the concept of reasonableness. With trade, industrial and business premises, there is a defence of having used the "best practicable means" to keep the nuisance to a minimum level. This will take account of factors such as local conditions, the current state of technical knowledge, and financial implications. Any customers confronted by a complaint will need to be clear about the reason for their white light. White lighting may be needed to improve visibility in a dangerous location such as a goods yard. "But if the reason for having those lights is just to make cameras see, then there is no reason for them to be there," says Ian Fowler. Technology advances, particularly in solid state LED illumination, have brought down the running costs of IR significantly, says Shaun Cutler.

Cameras record correct colour during the day by using an internal mechanical filter between the lens and the chip to remove colour distorting IR. After dark, the mechanical filter moves out of the way to allow IR light to reach the camera chip.

IR corrected lenses should also be used in these situations to ensure that images remain sharp and in focus under both white and infrared lighting conditions. The decision to adopt infrared can also affect the style of camera used. Infrared solutions, especially LEDs, tend to be more focused than white light in terms of where they point. But a dome camera can be looking anywhere, so the whole area generally needs to be lit. "There isn't much available by way of volume lighting for infrared," Fowler says. "People tend to go for white light when they are installing domes."

Pigram believes this may provide a driver for resurgence in the use of traditional PTZ cameras. With a PTZ system, infrared 'searchlights' can be used to follow the cameras without disturbing neighbours. "You couldn't do that with white light," Fowler says. "Those who can't rely on white light but want more efficiency and a longer life may need to use LEDs with PTZ cameras."

Tighter focus

There may also be greater use of detectors to switch on lighting when needed, coupled with a tighter focus for the lighting. "I can see people generating lighting corridors within maybe 3m or 4m of the building, and not being too bothered about what is going on in the larger precinct of the yard," Fowler says.

CCTV often needs to make use of lighting provided for other purposes. Much of Buro Happold's security consultancy work is on prestigious new buildings where the lighting for CCTV has to work with the general illumination and client/architect requirements, says Bob Holmwood. "We design CCTV systems to work under the light available, or provided to us by specialist lighting teams," he says. "We qualify this approach using software we have developed to ensure that the operational requirements will be met. We can ensure that there is enough light for the CCTV system and security officers on patrol, without intruding on adjacent properties."

It is not only individual householders who will welcome the clampdown, but by campaigners who are aiming to restore the darkness of the skies. "I think this act is a marvellous thing," says Ian Fowler. "I'm sick and tired of seeing the orange pall over cities."