Your surveillance system is only as strong as the camera that powers it. If you plan on recording video surveillance in anything but sunlight, it’s important to consider your camera’s ability to work in a variety of lighting conditions. Will the camera work in low light? Will it work in the dark? These are all important factors to consider when purchasing a surveillance system.
First off, you need to determine the camera’s ability to capture video in a variety of conditions. At the top of that list is whether the camera can or can’t capture video in darkness, something that’s measured by a rating system called “Lux.” Lux is basically the way light is measured. If you’re measuring how dark it is in a room or outside, the lower the Lux rating, the darker it is. When referring to surveillance cameras, a Lux rating determines the light conditions the camera will be able to operate in.
A simpler way to understand Lux is:
A Lux rating of .0002 is equivalent to a moonless clear night with airglow, which is basically the natural light from the sky from stars. A .01 Lux is equivalent to a quarter moon on a clear night, where 1 Lux is a clear night with a full moon. A 3.4 Lux is twilight conditions, while 50 Lux is lighting in an average family living room, and lastly 320-500 Lux is common office lighting.
Most camera specifications will list the Lux of a camera, so when a customer asks me how a camera performs in a variety of lighting conditions, I am able to give them the camera’s Lux rating, and give them the appropriate analogy to explain to them on how the camera is going to perform in their specific application.
For example, some of our most popular cameras have low light capabilities with a Lux rating of .003, which I explain can capture video in light as low as that on a moonless clear night. So under average conditions with some light coming in from a window at night, the camera will be able to see with relative clarity.
Another important factor to keep in mind is that black and white cameras perform better in low light conditions both as far as Lux is concerned and the contrast you will get to be able to identify people or objects. A camera with true nightvision can only do this if it is equipped with infrared (IR) or LED (Light Emitting Diode) technology. Nightvision cameras with IR illuminators will generally be listed as zero Lux, which means that the camera will see in complete darkness with the aid of the IR illuminators.
Nightvision cameras will generally operate in color during the day, and when the light drops below a certain level, a built-in photo sensor will switch the camera to black and white with a special filter called an IR cut filter. For example some cameras will have a light threshold of 1 Lux, which means that up until that point, the camera does not require the night-vision IR LEDs. If you’re wondering whether you can see the infrared or LED technology, don’t worry you, you can’t. Infrared light is invisible to the human eye. The area that an infrared illuminator will light up will just look like clear black and white video when you view it on your video monitor. If you’re trying to covertly record, no one is going to be able to see the lights of the camera. The range of IR is determined by the number of IR LEDs (Light Emitting Diode) that the camera is equipped with–the more IR LEDs the longer nightvision range the camera will have.
For example a camera with 60 IR LEDs will see up to 100 feet in the dark. A camera with 23 IR LEDs will generally see about 30 feet maximum in complete darkness. Weather conditions will affect night-vision range. Humidity, rain, fog, snow and other extreme weather conditions will reduce the range of night-vision.
Another factor that figures into the night-vision equation is a nanometer (abbreviated nm). This is the most common unit to describe the wavelength of light, with visible light falling in the region of 400-700 nm. A majority of night-vision cameras sold on the market are between 750nm and 850nm.
These cameras will have a slight reddish/blue glow at the source of the IR light. Customers will generally ask if the nightvision light is invisible. The light that is shot out is completely invisible, but the source of the IR light at the LEDs on the camera, there be a glow. Only cameras that are equipped with 950nm and higher IR LEDs will be completely invisible. Those cameras are considerably more costly – starting generally at around $800, but the IR LEDs will be completely invisible.
So whether you are the United Nations Peacekeepers in the island of Cyprus monitoring the Green Line, or a homeowner monitoring their three bedroom ranch house in Athens, Georgia, these are some of the basic facts about surveillance cameras you will need to know.
Check out our entire line of surveillance cameras for day or night at BrickHouseSecurity.com
Gok is a Senior Surveillance and Sales Specialist at BrickHouse Security, and has been with the company since 2006. Gok attended the University of Chicago’s Laboratory Schools, and studied Journalism at Ball State University in Muncie, Indiana. Afterward, Gok moved to the divided Mediterranean island of Cyprus, and eventually established himself there as a journalist working for Reuters as their correspondent in the Turkish Cypriot north of the island.