As with any product or service, proper application is essential to maximizing a technology. Using video surveillance in outdoor applications or areas with inconsistent or inadequate lighting can be challenging, but there are ways to capture clear images worthy of identification.

Rui Barbosa, product manager for i-PRO Americas Inc., Rolling Meadows, Ill., said that, whenever possible, it’s best to use available light as opposed to infrared light to illuminate scenes, as this will give the security team a better image to work with.

“Lighting needs to be uniform and consistent, with no hot spots that can wash the camera out,” Barbosa said. “Cameras with wide dynamic range can maintain better images in varied lighting conditions, too. Consider using motion-detection lighting, which only turns on when it detects motion in the area. This can save energy and help draw attention to potential security breaches while guaranteeing adequate light for security cameras. 

“Be aware that rapid changes in lighting can cause some cameras to struggle to reset to the new light level. Make sure that the camera you choose can compensate for changes in light quickly when motion detection lights are utilized to not miss important details during the transition. When specifying artificial lighting fixtures, try to utilize lights with the same color temperature output so that camera sensors can accurately reproduce color,” he said.

Edging up advantages

Barbosa said that while sensor quality is the primary factor in low-light performance, the use of advanced artificial intelligence (A.I.)-based algorithms at the edge can significantly increase image quality in low light by removing noise and focusing image processing on the image’s important parts.

“Having edge-based A.I. that also enhances image quality is a valuable feature to look for on any camera being considered for low-light environments,” he said.

When available lighting is an issue, lighting can be augmented with thermal imaging, infrared LED illumination and radar video devices.

Karl Radke, director for the Midwest business area at Axis Communications, Chelmsford, Mass., said it’s important to note that thermal cameras are passive. Technically, they don’t illuminate a scene, but instead measure the thermal radiation (heat) present.

“The advantage of a thermal camera is that it is not dependent on visual light to detect humans, cars, animals and other objects. However, thermal cameras would never be able to provide positive identification. These cameras are often used in perimeter protection scenarios when a high alarm accuracy is needed, but positive identification could be achieved via a physical response team or additional visual cameras,” Radke said.

Near-infrared light—which the industry typically refers to as infrared—is different. 

“Infrared cameras capture a part of the spectrum that image sensors can detect but the human eye cannot see,” he said. “This is useful when you either don’t have the budget to provide visual lighting in an area or you want to keep the video surveillance discreet. The downside of infrared lighting is that the camera needs to use black-and-white mode, so accurate colors will not be reproduced. That said, there are products available today that can provide accurate colors even when light levels are low, such as the Axis Lightfinder 2.0.”

Radar devices, Radke said, emit radar waves and register the reflections coming back to the device. They work well in low-light or inclement weather situations and are particularly good at measuring the speed and direction of objects. However, they provide even less identifiable features than a thermal camera.

Axis published a “Lighting Design Guide” that explores best practices when designing lighting for video surveillance systems.

Among the things that systems integrators should understand include:

• What light is and how to measure it
• Backlighting and its effect on video quality
• Brightness and glare and their effects on video quality
• Reflectivity of light on various surfaces
• Light beam patterns and illumination distances
• Principles of infrared light
• Light and wavelengths visible to the human eye

Other developments

The integration of new network radar solutions with network devices such as cameras and IP audio solutions is driving incredible new possibilities for surveillance lighting.

“Using network radar units, the radar can auto-track a subject by controlling a nearby pan/tilt/zoom camera, potentially improving both the detection and identification capabilities of a camera system. Similarly, new forward-facing radar technology can identify an object in a scene with poor conditions and identify that same object within the camera’s stream—often before the camera itself can classify the object,” Radke said.

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