We all know the saying “crime never sleeps.” The truth is reality isn’t far off. According to U.S. News, crimes like murder, sexual assault and robbery happen more frequently at night nationwide, with cities like Cincinnati, Ohio; Austin, Texas; and Dallas experiencing more overall police incidents during the evening than any other time.
For the integrator, this means the most competitive security solutions will be able operate reliably, day and night, to address these incidents—the only problem is, without proper illumination, most traditional video surveillance systems simply can’t.
The Importance of Illumination
In the age of video analytics, especially, we’ve seen this issue create a serious security challenge. A standard security camera operating — without lighting — at night can yield dark, grainy images at best. Because video analytics require clear, high resolution images to deliver actionable results, low-quality images stop detection, identification and incident prevention in its tracks. When integrating a round-the-clock security solution, it’s important to understand what options exist to mitigate this problem.
Built-In Versus External
A popular lighting option is when LEDs (light emitting diodes) are integrated into the camera. The appeal of these cameras, with built-in LEDs that encircle the lens, is that they provide an all-in-one solution. However convenient they may be, these options often create limitations. The range for visible LEDs built into a surveillance camera is around 150 feet — and typically only covers a 30° field of view (FOV), even though a standard camera’s FOV is often 90°.
This creates “hot spots” in the middle of the camera view and can cause a total “white out” of the rest of the image. Additionally, LEDs encircling a lens are known to cause heat buildup, which can degrade the lens over time. External illuminators, however, are able to minimize heat accumulation and offer much longer illumination ranges — up to 900 feet, in fact, when using infrared (IR) illuminators. Because mounting external lights also enables deployments to adjust the angle of the illumination and pair any given camera lens with the perfect range/wavelength, independent illuminators represent a versatile solution.
Visible Versus Invisible
An equally important consideration is the type of illumination to install. Visible illumination — or white light — operates at a low cost, making them especially attractive when compared to other options, such as fluorescent or incandescent bulbs. These options are also durable and insensitive to vibration; and they feature an extremely long life. Because they utilize visible light, moreover, they enable color image capture and can even act as a deterrent to suspects when used as a floodlight.
Drawbacks to consider include the fact that they do, however, create light pollution and operate at comparably shorter distances. Invisible illumination, on the other hand, is detectable only by black-and-white or true day/night cameras, making any camera placement with invisible illumination covert. IR illumination of this sort offers a much longer range than visible light, making them an effective choice for security cameras tasked with monitoring larger areas. Drawbacks to consider include the fact that they can only produce black-and-white images, which can hinder object recognition and search analytics based on color.
Best Practices for Choosing an Illuminator
When it comes down to it, there is no “one-size-fits-all” lighting option for security deployments. Each surveillance system requires a unique solution. In a smaller space, for example, the ideal invisible lighting option is a short range, infrared illuminator. In these cases, higher wavelengths (>940nm) are truly invisible and offer a wide area of coverage. In a larger space, or in an outdoor setting, medium range infrared illuminators with lower wavelengths (<850nm) provide illumination at longer distances, though they also produce a faint red glow.
When video analytics require lighting at longer distances for ranged detection, however, this may be considered a worthy trade-off.
Consider these factors when specifying lighting for your surveillance system:
• The angle of illumination. The FOV of every camera is different, making it important to choose a lighting option that best matches the camera lens being used.
• Dual or triple mounting bracket. If a p/t/z camera is deployed, or if the area being surveilled is too large or wide for one illuminator to do the trick, mounting brackets allow the installation of two or three, side-by-side devices. This strategy doubles the angle of illumination and increases illumination distance by up to 40%, in the case of a dual mounting bracket and increases illumination distance by 75% when using a triple mounting bracket.
• Both options allow integrators to install a hybrid lighting solution depending upon the specific needs of the deployment (i.e. a mix of both visible and invisible lighting).
• Make sure to target specific points of interest, such as gates or doorways, with both your camera and your illuminator to ensure the most important areas are covered.
