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What Major World Cities Look Like at Night, Minus the Light Pollution

blogs.smithsonianmag.com

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Re: What Major World Cities Look Like at Night, Minus the Light Pollution

#11

Post by seanmcdirmid »

SoftwareMaven wrote: post #4
jcr wrote: post #2

I doubt I'm the only one who read the article with the hope of finding some new technique to remove light pollution from images to show off the stars... and was mildly disappointed to find out the beautiful images were just cut-n-paste jobs (albeit outstanding ones). I'm wondering what kinds of techniques exist for removing light pollution? Spectrum sensitivity? Spectrum filtering on exposure? Post processing?

Tucson, Arizona uses sodium vapor lighting for all its street lighting specifically to allow the nearby observatories easily filter the light pollution.

I attended a conference in Tucson last fall and...being jetlagged, did a nice walk at 4AM in the desert behind our resort. It was really amazing, I hadn't seen shooting stars in decades.

Re: What Major World Cities Look Like at Night, Minus the Light Pollution

#12

Post by jcr »

sp332 wrote: post #7
christiangenco wrote: post #3

Earlier quoted context omitted.

You most certainly are not. I wonder if you could get it done with some kind of manual HDR: tracing out the skyline to explicitly say "stuff below the line should be from the low exposure photo, stuff above from the high exposure photo." Disclaimer: I know nothing about photography.

The problem with light pollution is that the light bounces off of water, dust, and smog in the atmosphere, and back down into your eye/camera. So when you look up, the sky isn't darker, it's a lot brighter! You would need a way to subtract the extra light.

Though it won't help our eyes any time soon, something along the line of "Adaptive Optics" [1] could possibly address at least some of the issues you mentioned when creating images. Getting tech from the world's beset telescopes into consumer/pro camera gear might be asking a bit much at the moment, but eventually it could become possible. If it was done, a big issue would be having countless people shining lasers into the sky.

[1] http://en.wikipedia.org/wiki/Adaptive_optics

Re: What Major World Cities Look Like at Night, Minus the Light Pollution

#14

Post by danso »

If you were in New York City during Hurricane Sandy, in the lower half, at least, you got a taste of this first hand.

I had to walk home into the unpowered section of Manhattan every night from work. I took some photos during that time. Unfortunately, as it was still overcast, we never did get a chance to see the stars from downtown Manhattan:

http://tumblr.eyeheartnewyork.com/post/37636219209/i-finally...

Re: What Major World Cities Look Like at Night, Minus the Light Pollution

#15

Post by hippobravo »

hobb0001 wrote: post #6
duck wrote: post #5

After living in Alaska for several years, I don't really think that is how cities would look at all. With just stars and even the aurora borealis, it is incredible how pure darknesss looks. I really didn't know how much light pollution effected the sky until living there, but even in small towns and other less populated areas the light from various sources changes the skyline.

Whew. I was wondering if I was the only one who has been out in the mountains and other rural areas, but have never seen a night sky like these.

If there is literally no light pollution in your vicinity (like in the middle of northern canada, hundreds of kilometers away from the nearest small town) on a very very clear night it does look something like this.

I've never seen the milky way with that much color, but the amount of stars and the star clouds of the milky way are not that far off.

The title is not just removing light pollution, it is removing most of the atmospheric interference. On clear cold nights you can get something close to this if you're truly in the middle of nowhere. Emphasis on clear and no towns within a few hundred kilometers.

Re: What Major World Cities Look Like at Night, Minus the Light Pollution

#17

Post by snowwrestler »

seanmcdirmid wrote: post #11
SoftwareMaven wrote: post #4

Earlier quoted context omitted.

Tucson, Arizona uses sodium vapor lighting for all its street lighting specifically to allow the nearby observatories easily filter the light pollution.

I attended a conference in Tucson last fall and...being jetlagged, did a nice walk at 4AM in the desert behind our resort. It was really amazing, I hadn't seen shooting stars in decades.

It's only a couple hours from Tucson to the Kitt Peak Observatory, where they have astronomy programs for the public. I talked my wife into doing it when we were there visiting friends last year.

I highly recommend it. The astronomy is fairly basic, but the experience is incredible: You're up on a big mountain, surrounded by gigantic telescopes, in the middle of a vast desert wilderness. It's freezing cold outside after dark. When the program is over, you have to drive down the upper half of the mountain without headlights to protect the observations that are happening.

Re: What Major World Cities Look Like at Night, Minus the Light Pollution

#18

Post by Anechoic »

hobb0001 wrote: post #6
duck wrote: post #5

After living in Alaska for several years, I don't really think that is how cities would look at all. With just stars and even the aurora borealis, it is incredible how pure darknesss looks. I really didn't know how much light pollution effected the sky until living there, but even in small towns and other less populated areas the light from various sources changes the skyline.

Whew. I was wondering if I was the only one who has been out in the mountains and other rural areas, but have never seen a night sky like these.

Having spent some time in the White Mountains in northern New Hampshire, the sky I saw looked a lot like those pictures, I think they are fair depictions. I definitely remember it as being my first and only time when I could actually see the Milky Way.

(it's also a little freaky being above a thunderstorm at night)

Re: What Major World Cities Look Like at Night, Minus the Light Pollution

#19

Post by jervisfm »

danso wrote: post #14

If you were in New York City during Hurricane Sandy, in the lower half, at least, you got a taste of this first hand. I had to walk home into the unpowered section of Manhattan every night from work. I took some photos during that time. Unfortunately, as it was still overcast, we never did get a chance to see the stars from downtown Manhattan: http://tumblr.eyeheartnewyork.com/post/37636219209/i-finally...

Wow, those are really beautiful shots that you took. I did wonder what being in lower Manhattan was like after the storm and your photos capture that first hand. Thanks for sharing.

Re: What Major World Cities Look Like at Night, Minus the Light Pollution

#20

Post by bedris »

danso wrote: post #14

If you were in New York City during Hurricane Sandy, in the lower half, at least, you got a taste of this first hand. I had to walk home into the unpowered section of Manhattan every night from work. I took some photos during that time. Unfortunately, as it was still overcast, we never did get a chance to see the stars from downtown Manhattan: http://tumblr.eyeheartnewyork.com/post/37636219209/i-finally...

Those photographs are stunning – and haunting. Thanks for sharing them.
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