Turning Nighttime into Sight Time

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I live in a wooded area. There are no streetlights nearby, and after the sun sets it can get pitch black, especially on moonless nights.

Sometimes I take the garbage out before going to bed. The garbage can is in a locked bin that sits in a remote corner of the driveway where the houselights don’t reach. Feeling my way in the darkness, I hear the night sounds in the woods. A mockingbird’s song. A rustle in the bushes. Could it be a raccoon? A fox? Even a bear?

That’s when I wish I had night vision.

Both humans and mammals depend upon visible light to see. But many nocturnal animals, including raccoons and opossums have unusually large eyes to help them see better in the night, helping them sneak up on sleeping or unsuspecting prey. Carnivorous animals such as red foxes use good night vision for hunting as well.

As an article on Sciencing.com points out, “Some nocturnal animals have pupils that dilate to allow maximal light exposure. Animals with good night vision also have many light-receptor cells, known as rods, that help them control their eye sensitivity to light. Most cannot see as well during the day and cannot see color. Certain snakes have night vision too—the pit viper combines their sight with pits near their nostrils that detect heat to hunt at night. Cuttlefish, a type of cephalopod, have eyes that are just as functional as normal human eyes, which they use to hunt crabs and fish at night. Owls are one of the species of nocturnal birds that use their excellent night vision for hunting."

Dr. Cheryl Murphy explains
night vision goggle technology.



Although humans lack the ability to see in the dark, they can compensate for it with the help of technology. Night vision goggles are a popular option for hunters and other outdoor enthusiasts, and the military. Most rely on some type of sensor that can detect heat, also called infrared, or thermal, energy.

“Night vision googles essentially work by converting low levels of photons—or in some cases infrared light emitted by animals and objects in the dark—into higher levels of electrons,” explained science writer Cheryl Murphy, OD. As Dr. Murphy shows in her accompanying illustration, the original photons captured are first turned into electrons and then multiplied to make their signals stronger. “Next, they are projected onto a phosphor screen which flashes and lights up as the electrons continually hit it in a particular pattern of varying strengths. These patterns result in a crude picture of what you would not otherwise be able to see in such low levels of light,” she observed.

An interesting point: since all colors of light or wavelengths of photons cannot be translated when they are generically converted to electrons in night vision goggles, scientists picked the color green when choosing what wavelength to show the electrons in. “Green is not only the wavelength of light to which human eyes are most sensitive but also a color that is very easy on the eyes and comfortable to look at for extended periods of time,” Dr. Murphy said.

Who uses night vision devices? I posed the question to Mark Steinberg, senior technologist for B&H Photo, the New York City-based superstore that sells everything from professional-grade cameras and audio equipment to high quality optical products.

“Originally, the market for night vision binoculars and scopes was limited to people with military interests,” said Steinberg, adding that some of the first night vision products available to consumers were made by a company owned by Essilor.

According to Steinberg, consumer interest in night vision devices picked up when the hit movie “Silence of the Lambs” came out in 1991. “That did more to bring these products to the public’s attention than anything in the last 50 years,” he says.

Steinberg pointed out that the market for night vision products is now quite varied, as people have found more creative uses for them. “Believe it or not, we get a lot of calls from farmers who want to see if predators are poaching their stock at night. They like to use the scopes with a headworn mount and one eyepiece. They also use them for animal husbandry, to see what’s going on in the barn. Noctural animals have their own clocks, and you know, sometimes nighttime is the right time.”


Avangard Optics' NVG1Pro 1x26 Night Vision Binocular features a built-in infrared illuminator for casting extra infrared light on targets.
Hunters are big customers for head-mounted rifle scopes with night vision capabilities, Steinberg said. Private security firms and private investigators also use night vision devices, as do search and rescue teams who need to detect infrared images generated by body heat from survivors who may be trapped under rubble.

Fishermen are also avid users of night vision devices. As Steinberg pointed out, “A lot of fishing takes place at night, when it can be dangerous to be on the water in a canoe or raft.”

There are many types of night vision goggles on the market, ranging from basic models that cost several hundred dollars to highly advanced systems that use a technology known as Forward-Looking Infrared Radar (FLIR) that sell for as much as $40,000. Yet even lower-end products boast impressive features, such as the Avangard Optics' NVG1Pro 1x26 Night Vision Binocular & Headband Mount Kit, which B&H Photo sells for $579. According to a description on B&H’s website, the kit includes “a night vision binocular and headgear with a fully adjustable headband and a flip-up adapter. At the core of the included NVD (Night Vision Device) are two bright-light-protected first generation intensifier tubes that convert infrared scenery to visible images using ambient infrared light. For very cloudy dark nights or for environments in complete darkness, when ambient IR illumination is low, the binocular features a built-in infrared illuminator for casting extra infrared light on your targets. Other highlights are a 1x optical system, individual focusing, and diopter adjustments.”


FLIR Recon BN10 Thermal Binocular are equipped with thermal imaging cameras for each eye.
For those with deeper pockets, the FLIR Recon BN10 Thermal Binocular might be an enticing option. Produced by a company called FLIR, which makes and markets products for responders and military personnel, the BN10 sells for $18,747 on Nightvisionguys.com, a website specializing in these types of devices. According to the site, the BN10 is “the world’s first and only true thermal binoculars.” Equipped with two thermal imaging cameras, one for each eye, the Recon binoculars provide “an authentic binocular viewing experience, with a true depth-of-field capability.” Other features include two magnification levels, a 3.3x magnification level, selectable 2x e-zoom, dual diopter adjustment and interpupilliary distance (IPD) adjustment.

Not surprisingly, the export of such a sophisticated, military-grade gear is strictly regulated by the federal government. As NightVisionGuy.com advises, “The sale, transfer, transportation, or shipment outside of the U.S. of any product prohibited or restricted for export without complying with U.S. export control laws and regulations, including proper export licensing, documentation or authorization, is strictly prohibited and may result in civil penalties and/or constitute a federal crime.”

Unless you’re an international arms dealer with a contract from the Department of Defense, don’t even think about trying to take this stuff out of the country. For the rest of us who like to hunt or fish at night, or even spot critters in the yard when taking out the garbage after dark, there are plenty of legal options for turning nighttime into sight time.