Lighting for Surveillance Situations

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More than in most other applications, surveillance video devices need to be specially suited to their environment. Unlike a camera used for other purposes, surveillance gear rarely allows you to make changes to the environment you’re recording, so it must be able to work in the conditions in which it’s installed. Most installations won’t allow you to add or remove light sources to accommodate the needs of your camera, so you should know what features to look for and how they’ll effect your recording.

An IR cut filter, specifically a mechanical IR cut filter, allows a camera to switch back and forth between color and monochrome video in conditions when it’s too dark for color. Recording night vision video uses infrared light, which human beings can’t see. IR camera sensors have trouble recording normal color video, and require a filter that corrects coloration, which is automatically removed when illumination falls below a defined threshold. When light levels increase, the filter slides back into place. Most cameras will list their lux ratings for color and black-and-white video separately, so you can know when the filter engages and disengages.

Nest Cam IQ Outdoor Security Camera

Wide Dynamic Range (WDR) is a feature designed to compensate for bright and dark areas in a frame. This is often a useful feature for cameras monitoring building entrances/exits or areas like garages and loading bays, where some portions of the scene will be in shadow and others in direct sunlight. This is most often achieved by combining multiple exposures; long to capture the areas in shade and short to capture the brighter ones. This can have a negative effect on low-light recording, so the feature may be turned off on most cameras.

Hikvision 2MP WDR EXIR Bullet Camera with 2.8mm Fixed Lens and Night Vision

Backlight Compensation kind of does half of what WDR does. It doesn’t balance lighting throughout an entire frame, but only what’s in the foreground in situations where there are bright light sources in the background. This will allow a subject’s face to be seen when they stand in front of a sunny window, for example, but will not prevent the area behind them from appearing blown out.

Swann 4MP Outdoor Network Turret Camera with Night Vision

High Light Masking blocks a light source to prevent “haloing,” or an image being blown out. If, for example, a car is driving toward a camera with its headlights on, if the camera senses enough light to degrade the rest of the image, it will effectively block the light source, ignoring enough of it to be able to continue capturing video throughout the rest of the frame. It’s the high tech equivalent of putting your hand in front of the sun when looking at the sky on a sunny day.

Digital Watchdog Infinity Series B1367WTIR 620TVL Indoor/Outdoor Day & Night IR Bullet Camera with 3.3-12mm Varifocal Lens

Gain Control can compensate for a poorly lit scene. By adjusting gain levels, you can increase light sensitivity. Unfortunately, increasing gain also increases the amount of noise in an image, as well as bandwidth requirements. Automatic gain control (AGC) is a common feature meant to adjust levels to provide the optimal image as conditions vary. Look for noise-reduction features to get the most from AGC.

Arecont Vision AV2110 IP MegaDome Color Camera

If you need help deciding what features are most important for what you need to keep an eye on, please contact one of our surveillance specialists to get some help. Stop by the B&H SuperStore in New York, speak with a sales professional on the telephone at 1-800-606-6969, or contact us online via Live Chat.

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