The Best Night Vision Goggles $30,000 Can Buy
Just the tech you’ll need to execute covert
nighttime operations — such as a midnight ride on an illicit trail
It started over a backyard beer. We were in Marin, just north of the Golden Gate Bridge, enjoying a sunny afternoon and a view of Mount Tamalpais. I was thinking out loud, brainstorming with a newly made acquaintance, and a bit too far into my cups. “Why not mountain bike the entire Pacific Crest Trail,” I asked, “all the way from Mexico to Canada?” I’m no mountain biker, but my livelihood as a writer depends on finding adventures, and then writing about them. “No problem! Completely do-able,” replied Zander, whose last name must remain anonymous for reasons that will soon become clear, “except for where the PCT cuts through Yosemite Valley.” Strictly speaking, the entire 2,663-mile long trail, widely known by its acronym, is off-limits to mountain bikers, but Yosemite’s trails are patrolled.
Spreading out a USGS topo map, he calls my attention to the problematic stretch through Yosemite, 42 miles between Devils Postpile and Glen Aulin. His thick finger points to where the PCT cuts through Tuolumne Meadows, the largest campground outside of the valley, complete with RV hook-ups, post office and general store. “Rangers everywhere,” he says, pausing for a long moment of contemplation. “The only way to get through,” he decides, suddenly brightening, “is with night vision.”
Marin is a funny place, full of contradictions. On one hand, there’s an unmistakable hippie vibe. Earth shoes and hot tubs are (still) the order of the day. Yet it’s now the richest county in California, and with great wealth come great egos. Scratch the laid-back and bohemian surface, and a righteous, authoritarian streak can emerge. Marin’s great cultural claim to fame, mountain biking, is a perfect example. Mount Tam, which pushes the center of the county up like a tentpole, is where the sport was invented in the ’70s. But after vehement backlash from hikers and equestrians in the ’80s and ’90s, most of the single-track trails on the mountain are now off-limits to bikes. Mountain bikers have become a persecuted minority in their ancestral homeland.
Forty-something years old, Zander embodies the sort of contradictions that define the place. By day he’s a buttoned-up engineer of some repute. By night he’s an outlaw, going to great lengths to steal the forbidden single-track on Mt. Tam. At least two evenings each week for nearly 20 years, he and a few like-minded friends have been riding Mt. Tam at night, illuminating the trails with lights that they build themselves. The first models were hacked together from junkyard parts: a headlight up front and a car battery strapped to the rear rack. Early efforts used incandescent bulbs, then halogen, then high intensity discharge arc-lights. Then, 10 years ago, a German company called Lupine released the first truly usable LED-based bike lighting system, and the number of night riders exploded.
On a clear night in Marin, one can look up at Mt. Tam and pick the night riders out, plainly visible as twinkling lights whooshing down the side of the mountain. It’s a trick that local authorities have discovered as well. One Wednesday evening not that long ago, Zander and his buddies pushed off from the top of Mt. Tam and found themselves face to face with Marin’s finest at the bottom. They got off with a warning. “That’s when I started to wonder about advanced night vision,” Zander says.
As a technology, the night vision goggles are pretty easy to grok. One is simply looking through a viewfinder at a video feed piped in from a special camera — one vastly more sensitive to light than is the human eye. Ambient light — from the moon, from the stars, even from the faint airglow of the upper atmosphere — is amplified so that one can see in the dark. It’s the video equivalent of turning up the gain on a mike.
But there is high gain, and then there is high gain: whereas a typical “Gen 1” system might amplify the ambient light by a factor of a thousand, the super-advanced “Gen 3” systems can reach amplification factors 50 times higher. One can find Gen 1-style night vision goggles on Amazon for as little as $300. In contrast, a good Gen 3 system costs a hundred times as much — and, by law, you need to be a US citizen in order to even look through the eyepiece.
The irony is that both versions, the Gen 1 and the Gen 3 (as well as the intermediate grade, sensibly known as “Gen 2”), are all analog technologies. The rest of the camera world has long since gone digital, but night vision is the last stand of a technology that has been around since Edison’s time. All night vision is built around the same core technology: the vacuum tube — specifically a video camera tube. Those are the tubes that TV (and then video) cameras used before the technology all went digital. Video camera tubes, as it turns out, make the best light amplifiers.
First, a dim nighttime image gets focused onto the front of a video tube, which is covered in a photosensitive chemical. The chemical absorbs the light and spits out electrons into the vacuum of the tube. (This is Einstein’s famous photoelectric effect, for which he won a Nobel in 1921.) So far, so good: this is how all tube-based video cameras work. Once inside, the electrons are accelerated and focused by means of a high voltage and, in the case of advanced night vision, through a very thin slice of a very thick bundle of optical fibers. As the highly charged electrons stream through the fibers they invariably bounce off their walls, knocking free more electrons — and multiplying the original signal.
Each of those fibers is essentially a pixel in the now-bright nighttime image that gets transmitted to the back end of the tube. There we have Einstein’s photoelectric effect again — but operating in reverse. The back of the tube is typically painted with a green phosphor, a chemical that absorbs incoming electrons and re-emits the energy as photons. That chemical is typically the same green phosphor used in old-fashioned monochrome CRTs — the source of night vision’s signature greenish glow.
To poach mountain bike trails it was clear, to Zander anyway, that no commercially available night vision was going to cut it. Not only are conventional goggles relatively dim, they also all cantilever the image intensification tubes in front of the user’s head — imagine a pair of binoculars strapped to your face. While useful for passive surveillance — hunting, perhaps — you can’t safely mountain bike with all that hardware dangling from your helmet.
What we needed was what the military’s Special Ops teams use: a design which takes the requisite hardware and folds it back around a soldier’s face. The O’Gara Group, a defense contractor based in Cincinnati, builds some of the very the best of these low-profile goggles. Each of their AN/PVS-21 Low Profile Night Vision Goggle helmets costs $30,000 and you can’t buy one without a security clearance. Stan Babb, the director of business development at O’Gara, jokes that he could tell me exactly who uses their AN/PVS-21, but if he did, he’d have to kill me.
Even so, Babb was nice enough to eventually hand over a test unit on the flimsiest of excuses: that I was a journalist, and I wanted to take the rig for a test drive. It was a five-month conversation, and along the way I had to prove that I was a US Citizen, and sign a document affirming that I would take a daily inventory of all equipment, because the technology is regulated by the Arms Export Control Act. I knew that O’Gara was serious about having me comply with the arms control act because only a few years before one of their competitors was caught sending the technology to China, and was fined $28 million.
What showed up in my mailbox was a gargantuan pair of helmet-mounted goggles that would be equally at home in Tony Stark’s armory and an optometrist’s exam room. Flipped up, the goggles rest on top of a light, plastic helmet. Flipped down, the goggles obscure my entire face, covering them with a riot of matte-black knobs, oddly placed lenses, and small infrared LEDs. There are wires everywhere, which plug into a remote battery pack mounted at the rear of the helmet. My wife refuses to talk to me when I wear the AN/PVS-21 around the house, because I look so ridiculous. But functionally, the design is quite amazing. It weighs a hefty pound-and-a-half, but I find that while wearing it I can do everything I normally do — from tying my shoes to washing the dishes — naturally, because whether the goggle is flipped up or down, the helmet’s center of gravity is always somewhere inside my head. My wife is less impressed. “What’s wrong with a $30 headlamp?” she wonders.
I arrive in Zander’s garage a few hours before dusk, lugging a big black hardcase behind me and swinging it with two hands up onto a workbench. There’s a rack of bikes on the back wall, and bin after bin of electric and mechanical components left over from light-building projects, but all eyes are on the hunk of ballistic-grade plastic before us. It’s me, Zander and his night-riding buddy Chris, a wiry machinist, former custom-frame builder, and competitive weekend racer. Stepping back to let Zander have a look in the case, I clue Chris in on our plan. Here, in the man-cave, I expect to find a more sympathetic audience. After asking what the goggles are worth, Chris, not missing a beat, quips, “Finally, an accessory that costs more than my bike!”
Zander, meanwhile, is chomping at the bit. “There’s just something about stuff that comes in Peli cases,” he says, snapping open the latch on each side and cracking the lid. Packed in a sea of foam are the helmet, the LPNVG, a mess of cables and batteries, and an auxiliary night vision telescope. The telescope is a special surprise bonus from the nice folks at The O’Gara Group, and fitting the pieces together we realize that the night-scope has a video-out, which can be fed into the goggles’ Terminator-style heads-up display. At about $30,000, science-fiction becomes science-fact: there is a bottle-cap-sized projector on the side of the goggles that floats an image directly in the wearer’s line of sight. A tiny joypad on the side of the goggles controls that tiny screen. “Like all things military,” Zander comments, appreciatively, “it’s designed so that someone who has played Nintendo all their life can operate it.”
Zander sticks the night-vision helmet and night-scope in his backpack before he and Chris lead me to the Tenderfoot trailhead, where the base of Mt. Tam meets the village of Mill Valley. Tenderfoot is a wide single-track that climbs about one and a half miles to Mountain Home, a landmark inn on a high ridge. The trail is one of the few left on Tam that’s still legally open to mountain bikes. However, a sign at the trailhead informs us that the trail is closed from sunset to sunrise. We press on, taking our chances.
After climbing well out of range of Mill Valley’s streetlights, we dismount at a wide swoopy curve. Even though the moon is full, tall trees and a thick canopy of leaves have us in almost pitch blackness. The three of us squint at each other to decide who’s going to be the guinea pig. Chris laughs: “I’m just here to watch you guys crash your $30,000 helmet.” I beg off, still getting used to my borrowed bike. That leaves Zander, who stuffs the night vision helmet onto his big head, cranks down on the chinstrap, and flicks on the image intensifier. “Wow,” he says, looking around, “it really balances out the contrast and the brightness nicely.” Then, from behind the night vision mask, I see his brow crinkle as he adjusts the focus on the twin lenses. “But the tunnel vision…” he glances down at his pedals as he says it, “they should call it between-the-handlebars vision.”
“Better go fast then,” says Chris. And with that, Zander wheels uphill and into the gloom. I try to follow his progress up the trail by switching the night vision telescope that he has left behind to hand-held mode, but he’s riding on a thin shelf cut into a very steep canyon, and is soon out of my scope’s line of sight. Twenty-five minutes later we hear a rustling, and then a swooshing sound. We can hear him coming, but with the lights off, we can’t see a thing until Zander is nearly on top of us and hooting with excitement. Chris and I are diving off the sides of the trail for cover as Zander power-slides to a one-handed stop, fist-pumping like a pro-bowler who’s just nailed a seven-ten split. Zander is talking excitedly as he struggles to flip the night vision apparatus up and away from his face — something about weird depth-of-field effects — when he suddenly pauses and says, “My God, is it really this dark out? I’d be blinded by a pair of headlights!”
Then it’s my turn to wear the helmet and take a run. I switch on my “high beams” — two tiny infrared LED lights built into the helmet that bathe my surroundings in a light invisible to the human eyes but plain as day to my bionic ones. I hardly need the extra illumination. The moon blazes like a searchlight through the trees. The forest itself is lit up as if a megaton bomb of glow-in-the-dark paint had just detonated at my feet. The world through the goggles is resolved in every shade of phosphor green. The soundtrack as I pedal up Tenderfoot is of my own heavy breathing. I cannot help but think of the finale in Silence of the Lambs, when we see Buffalo Bill stalk Jodie Foster through the green-tinged vision of goggles a bit larger than the ones I’m wearing. It’s creepy and weird and pumping uphill is difficult, mostly because of the narrow field of view: I can’t see my feet when scanning the ground just ahead of me for obstacles, and so my balance is not what it should be. I stop and start.
The downhill part of the ride, however, is a revelation. The helmet is as comfortable on a bike as it was in my kitchen, and the faster I ride, the more my confidence builds until the tree trunks are flashing by like fence posts. I can see every monochrome detail: a leaf, hanging off a drooping branch, appears as a fireball blazing towards my head. I don’t miss my peripheral vision because I’m so focused on staying on the trail ahead. My problem is that all the road vibration is jiggling the helmet forward and the goggles are slowly inching down my face. I haven’t cinched the straps tightly enough. D’oh! This first ride is an equipment test, not a race, but I can’t fail to notice that stopping to adjust does nothing for my time.
The final test this night is a real race: between Chris and Zander, LED lights versus night vision, from the top of Tenderfoot trail all the way down the mountain: 700 hundred vertical feet over one-and-a-half miles of twisty single-track. We decide to use the Strava app to determine which rider had the fastest time and set the finish line at Mill Valley Beerworks, a gastropub near the base of the mountain. Then we go our separate ways: Chris and Zander make the climb back up Tenderfoot to the starting line, while I head to the bar to wait.
Chris is first, and Zander arrives 10 minutes later just as the bartender announces last call and so we each order two drinks. Then Chris and Zander pull out their phones and dial up Strava. The GPS data reveal that Chris hit a top speed of 23.5 mph while Zander clocked 21.5 — a less than 10 percent difference. “Not bad!” says Chris. Before Zander can fill us in on what took him so long, Chris takes a guess: “A little off-trail excursion?”
“I really wanted to vomit by the time I got to the top,” says Zander, noting that when he wore the goggles his depth perception seemed off, “so I waited a bit before going down.”
Chris nods: “It’s like a 3D movie, it sounds like a good idea, but 20 minutes in, you’ve got a headache.”
The run down, Zander says, was a blast. “The switchbacks were sketchy,” he says, “because the lenses are set with the focus at about 20 feet out.” That and the tunnel vision effect meant that you’re forced to keep looking ahead even while navigating the chicanes. “But the faster I went, the easier it got.”
The problem, it seems, was a jump.
“I hopped off a root,” says Zander, “and then the trail veered left, so I put my foot down.” Next thing he knows, he’s tumbling down into the ravine. “There was no trail under my foot,” he concludes. If he hadn’t crashed, he would have won the race.
The goggles, I am relieved to report, made it through the fall unharmed. Designed for war, they’re solid: steel and glass, and clearly meant to take a beating. Zander, while scathed, survived with his enthusiasm for night vision’s sporting possibilities intact. In fact, the fall seems to have inspired his mind to run ahead — thinking, plotting. First of all, he says, glare could be reduced and depth-perception augmented by turning off the infrared LED “head-lights” built into the helmet and custom-building a special infrared LED light rig which would mount onto the handlebars of the bike. And swapping out the stock lens for a set with a wider angle might address the tunnel vision, he thinks.
By the bottom of our beers, even Chris seems won over by Zander’s enthusiasm. “When these get down to $500,” he says, “I’m definitely buying one!”
“The use case is definitely stealth,” Zander continues, “With a little more practice I know I could make it work on the PCT and get through Yosemite.”
Maybe something like that would work in the near future, we all agree. But if the AN/PVS-21 is not yet good enough to get us down Mt. Tam without some mods, what good is it for, like, right now?
“I’ve got it,” Chris says, leading us like lambs. “Do you know what that night-vision helmet would be perfect for?”
No, what?” Zander and I ask in unison.
“Shooting people,” he says, with a matter-of-fact grin on his face. “Duh!”