Night-vision scopes.

Night-vision scopes.

Night-vision scopes.

The latest gadgets and tech toys.
March 27 2003 6:58 PM

It's Easy Seein' Green

Night-vision scopes make your closet the color of Baghdad.

Vision in the darkness
Vision in the darkness

Of all the military gadgets on parade on television, there's one you can bring home without spooking the neighbors into thinking you've gone postal. Night-vision scopes, once available only at defense contractor prices, can be found nowadays at Wal-Mart for less than $100. The new consumer models are less powerful than the military versions, but they're more portable, too. They're also more stylish, so you won't look like that creep from Silence of the Lambs.

Technology has made huge leaps since the first Gulf War, but the grunts in the field still wear the same AN/PVS-7 headsets manufactured for Desert Storm by Northrop Grumman. U.S. civilians can buy the PVS-7 for themselves, but prices start at around $2,500 and can run to more than four grand for the model used in the gulf. A much more attractive option—literally—is the Night Owl Aero, a sleek, lightweight, sub-$200 unit designed to be held in one hand rather than strapped to your head cyborg-style.

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The Aero is built around first-generation night-vision technology, which puts it two steps behind the third-generation PVS-7. But for amateur reconnaissance runs, it does just fine. First-time users inevitably gasp when they take the Aero into a darkened closet and press its illuminator button, which causes a small red bulb on the front of the unit to glow dimmer than a lighted cigarette. Looking into the eyepiece the first time is an oh-my-God moment. The illuminator emits infrared light (invisible to humans), and the Aero's circuits crank it up to a brilliant green, making the room bright enough to read the New York Times without squinting. Look away from the lens, and the room is pitch black. Brain to eyeballs: Does not compute.

Night vision works by converting photons to electrons. Incoming light particles (the photons) strikea plate that emits an electrical pattern in response. In the case of the Aero, the resulting signal is amplified 15,000 times and shown on a small video screen. But why is Baghdad by night—or your closet with the door closed—green? The human eye (or rather, the brain behind it) is better at differentiating subtle shades of green more than any other color, possibly a result of evolution among lush vegetation. Shifting the frequency of a night scope's monochromatic image from grays to greens makes it easier to discern shapes, shadows, and movement.

Night vision really stands out in the wild, where it illuminates a hopping animal nightlife far busier than a few chirping crickets. Some zoos give night-vision tours to watch the alligators feed in the dark, but even the local woods turn out to be full of bugs, bunnies, and deerwho conduct nocturnal raids on the flower garden. The Aero is fronted by a 2.5x magnification lens to overcome distance as well as darkness.

In urban tests, the Aero let me read the license plates of cars parked overnight on my block and watch local winos fumble with the contents of their brown paper bags at 4 a.m. Its super-sensitive vision could sometimes see through a slinky dress to reveal the outlines of underwear. But the more shocking discovery was that I wasn't alone in the dark. Through the Aero's eyepiece, normally invisible light sources shone as brightly as regular bulb. Motion detectors gleamed from doorways. Some downtown buildings sported infrared security cameras (why they don't just use a 1,000-watt floodlight, I don't know). Most surprising of all, other night-vision users were out and about. The insides of their scopes shone back at me like glowing green eyes whenever our gazes crossed paths. At an all-night outdoor rave, I spotted the local cops looking through second-generation police goggles from the darkened cab of their truck. Crime-spotting, or just girl watching?