Deploying CCTV at Night

By Deborah L. O’Mara | Jan 15, 2007
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Are customers going gaga over closed-circuit television surveillance (CCTV)? It’s only the beginning; this workhorse of security protection and detection keeps raising the bar in technology, making it suitable for a wide range of applications.

Homeowners continue to turn to video, which is outpacing all other segments of the electronic security market in growth, according to Joe Freeman, president and founder of J.P. Freeman Co., Newtown, Conn. According to Freeman’s study, Worldwide Video Surveillance Market 2006, the video surveillance market is expected to grow to $21 billion over the next five years. In addition, according to The Freedonia Group, Cleveland, surveillance and access installed equipment accounted for 24.7 percent of the $58 billion world security sales in 2005, with projections to continue.

CCTV cameras have evolved to the point where they have their own brains and microprocessor control that make them little computers. Lenses offer higher resolutions than ever, crucial for positive identification and recording of events.

Part of the proper deployment of cameras is being able to see in low, near-dark or no-light situations. Because CCTV can yield effective surveillance in all these scenarios, it can be deployed almost anywhere and under a host of circumstances.

Day-night and scene illumination cameras provide an important adjunct to any surveillance project, but confusion remains among installers regarding each of their capabilities. Both have their place, but understanding what’s at play with technology, and how they will perform, comes first.

Day-night cameras are able to adjust their lenses automatically to allow more light when conditions mandate. With a day-night camera, the iris responds to the lightness or darkness of the environment. However, these cameras may not operate as efficiently as the customer demands, and that’s when adding more light to the scene may be the answer. Another way to add light to cameras and the area under surveillance is infrared (IR) illumination.

The installer may not always be able to rely on low light or day-night cameras with low-lux ratings. Low-lux relates to the amount of light visible to the human eye, sensitivity and minimum illumination.

“If a dark night-time scene needs to be under critical surveillance, then infrared illumination is required no matter the lux rating of the camera,” said J.M. Gin, president and chief executive officer, Extreme CCTV Inc., Burnaby, Canada. Gin said installers regularly query him about a common dilemma, night scenes that stay dark even with low-lux cameras.

“Even though they may be rated at 0.05 lux, which is 20 times less than typical moonlight, some day-night cameras can’t see at night.”

“Much of the confusion is centered on camera specifications that are often misinterpreted,” he continued. “A scene at zero lux is completely dark to humans. If the same zero-lux scene is well-illuminated by IR, it still remains zero lux. But to an IR-sensitive camera, it will resemble a normal black and white daytime camera.”

Another technology that works in low or no light is thermal imaging, sometimes referred to as thermography. Thermal technology is the production of non-contact infrared or “heat” pictures from which temperature measurements can be made and assessed in order to trigger an alarm under preset thresholds. With thermal imaging, heat-sensing capabilities separate the objects from the background. For example, a person or vehicle will be highlighted against a darker background.

CCTV must be especially robust in infrastructure protection and homeland security, said John Love, manager, Homeland Security Systems Business Development, Night Vision Systems (NVS), Dallas. “Analytics are extremely important for enterprise systems with thousands of cameras.”

Higher resolutions in cameras with new capabilities and configurable functions in a design allow integrators to mix and match capabilities to the protection level, Love said. NVS recently introduced a camera that includes dual sensor capabilities—a thermal camera for intruder detection and a low-lux unit that provides alarm assessment. Options such as pan-tilt-zoom and TCP/IP networking capabilities are simple to add.

Knowing the nuances of CCTV is the way to go, especially as it continues to garner more security sales.    EC

O’MARA is the president of DLO Communications in Park Ridge, Ill., specializing in low-voltage. She can be reached at 847.384.1916 or [email protected].



About The Author

O’MARA writes about security, life safety and systems integration and is managing director of DLO Communications. She can be reached at [email protected] or 773.414.3573.





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