Don't it look like the dark?

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06/03/2008
I'm guessing exactly none of you loyal readers got the Magnolia Electric Co. reference in the title here, but the recent beautiful star-filled skies we've had up here in Maine have reminded me to give people a heads up about this release from Extreme CCTV. Essentially, its IR illuminators have been approved by the International Dark-Sky Association, a non-profit group that's trying to curb light pollution, something I'm all in favor of. There's nothing (well maybe a few things) that drives me crazier than the giant blaring lights used by a restaurant a few hundred yards away from my house to illuminate their parking lot, making our rural area in the middle of nowhere have roughly the same light pollution as Fenway Park. I never really thought about light pollution much until this New York article, which is really great. It's a long article, so I don't feel bad about pulling a big quote. For some reason, I find this part fascinating and depressing: Amateur astronomers sometimes classify nighttime darkness on the Bortle Dark-Sky Scale, which is based on a number of criteria, among them “limiting magnitude,” or the brightness of the faintest celestial objects that are visible without magnification. The scale, composed of nine points, was devised in 2001 by John E. Bortle, a retired Westchester County fire chief and a monthly columnist for Sky & Telescope. “One of the problems I was addressing was that younger amateur astronomers, especially east of the Mississippi, had never seen a dark sky at all,” he told me recently. “People will sometimes come up from the city and call me and say, ‘John, I’ve found this fabulous dark site, it’s totally black, you can’t imagine how good it is.’ So I’ll go and have a look, but it’s always poor. They have no comparison to work against.” In Galileo’s time, nighttime skies all over the world would have merited the darkest Bortle ranking, Class 1. Today, the sky above New York City is Class 9, at the other extreme of the scale, and American suburban skies are typically Class 5, 6, or 7. The very darkest places in the continental United States today are almost never darker than Class 2, and are increasingly threatened. For someone standing on the North Rim of the Grand Canyon on a moonless night, the brightest feature of the sky is not the Milky Way but the glow of Las Vegas, a hundred and seventy-five miles away. To see skies truly comparable to those which Galileo knew, you would have to travel to such places as the Australian outback and the mountains of Peru. So, another reason to dislike Las Vegas (not that I need one), but also something else to think about when designing security systems. I'm working on a story for July's upcoming IP White Paper focusing on low-light performance, so I asked Bob Grossman, head of his own R Grossman and Associates consulting firm, about what he does for low-light cameras. His answer: "The number one way to keep the bad guy out is to put more lighting in the area, or put IR illuminators in the area." What about a spot where light pollution is limited? "I haven’t run across a place where there’s a challenge. I haven’t run into an area where lighting wasn’t allowed. But the level that a camera will work well is fairly low lighting. You don’t need – with frame integration and other technologies - you don’t need a whole lot of light." That may be true, but I feel like this idea of "add light, make safe" is pretty universally adopted. And it makes sense. Criminals are unlikely to do bad things to people in well illuminated areas when they have an option of a dark corner, but I wonder if correct, minimal-polluting lighting is always used. The New Yorker article makes the point that many residences use an omnidirectional lamp in the front yard that doesn't do much more than blind everyone in the yard, ruin night vision and shoot a bunch of light into the sky. Of course, IR illuminators aren't going to make for safe places, but they can certainly cut down on light pollution in places where people are unlikely to travel - unless they're the wrong kind of people. So here's my plea to check out that International Dark Sky Association Web site and try to use approved lighting devices whenever possible. The stars above are one of the true wonders of our world and it would be a shame if future generations never got to truly appreciate them.

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