I wondered if a city-wide synchronised Pulse-Width-Modulation of LED lights could allow astrophotography (or even naked-eye astronomy) to be possible again, with a filter synchronised to the off-cycle.
LEDs’ potential to save our night skies
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Re: LEDs’ potential to save our night skies
#12Where I live, we have a small park, 500m away. You need to walk through it if you want to get to the city center from the small neighborhood we live in. To protect the wildlife, the lighting system has presence sensors, so as you walk or bicycle through the park, the way/street lighting turns on, you can walk, and just after you, it turns dark again. Really cool, especially the first time I went through it in the mid…
Those things drive me nuts. There is a walking path that I frequent, and I can't use it at night because they are spaced every 20-30 feet. When I am not under them, they are off and my eyes adjust to the darkness and as I pass under one it flips to full daytime brightness and blinds me. As soon as I walk away from it, everything goes dark again, but my eyes had adjusted to the daytime brightness of the lamps. And I know that in 30 feet, I have to do it again, for the next couple of miles.
Re: LEDs’ potential to save our night skies
#13> Thorp notes that modern CCTV cameras are “pretty great” even at low-light levels, while harsh light makes it hard for both human eyes and digital sensors to see. That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system”
Even then, couldn't you just use IR cameras with IR lights for illumination. I'm sure that comes with it's own set of issues, but strictly speaking is better for maximising surveillance while minimising human impact
Re: LEDs’ potential to save our night skies
#14Where I live, we have a small park, 500m away. You need to walk through it if you want to get to the city center from the small neighborhood we live in. To protect the wildlife, the lighting system has presence sensors, so as you walk or bicycle through the park, the way/street lighting turns on, you can walk, and just after you, it turns dark again. Really cool, especially the first time I went through it in the mid…
If it gets used a good bit, I wonder if the on/off cycles are even more impactful to the local wildlife than constant but more optimized lighting was in place.
I know if I was trying to sleep a constant source of light is easier to get used to than a randomly flashing source of light. And for nocturnal animals I'd imagine randomly losing the cover of darkness from time to time is probably a lot more stressful than just avoiding the brighter areas.
I'd be interested in seeing data. I really wonder which is better.
Re: LEDs’ potential to save our night skies
#15I hate outdoor LED lights so much, I won't be surprised if a couple decades or centuries from now we discover that these things have been doing permanent damage to people's eyes. It's getting harder and more unpleasant to walk at night, I can't see and my eyes legitimately hurt every couple of minutes.
Does this trigger you: Modern car LED headlights
There doesn't appear to be any standard being followed (anymore?) on brightness or angle or height (or shape). A selection of them are easy to confuse with high beams. Makes driving at night in the rain some kind of epilepsy inducing overwhelm of lights and reflections and lens flare coming from everywhere, reminiscent of the cyberpunk aesthetic.
Re: LEDs’ potential to save our night skies
#16I wondered if a city-wide synchronised Pulse-Width-Modulation of LED lights could allow astrophotography (or even naked-eye astronomy) to be possible again, with a filter synchronised to the off-cycle.
Los Angeles has the Griffith Observatory. To allow the city to have street lighting while not interfering with the observatory, the lights are sodium vapor lights that emit a specific wavelength that the observatory can filter out. Since LEDs also use specific wavelengths, this could have been done.
I was disappointed that the article didn't mention this, especially because they did mention sodium, but only as a pretty color.
Re: LEDs’ potential to save our night skies
#17I hate outdoor LED lights so much, I won't be surprised if a couple decades or centuries from now we discover that these things have been doing permanent damage to people's eyes. It's getting harder and more unpleasant to walk at night, I can't see and my eyes legitimately hurt every couple of minutes.
Does this trigger you: Modern car LED headlights There doesn't appear to be any standard being followed (anymore?) on brightness or angle or height (or shape). A selection of them are easy to confuse with high beams. Makes driving at night in the rain some kind of epilepsy inducing overwhelm of lights and reflections and lens flare coming from everywhere, reminiscent of the cyberpunk aesthetic.
At least in the UK this is being looked into by a government review.
Whether that will amount to anything or not remains to be seen, but at least the issue is being taken seriously.
Re: LEDs’ potential to save our night skies
#18I once lived in a city that had replaced street lights that cast light in a circle with modernised ones that cast a sharply delimited rectangle of light on the road, and didn't waste light in other directions. The thing was, the roads of this city were arranged as a footpath, then a grassed area with trees, then the lights, then the roadway. Only after the city had rolled out thousands of these lights did someone not…
Over here, joggers are frequently wearing headlamps to illuminate their way. Often combined with a light on their back. They can see and can be seen, which is safe.
Re: LEDs’ potential to save our night skies
#19Where I live, we have a small park, 500m away. You need to walk through it if you want to get to the city center from the small neighborhood we live in. To protect the wildlife, the lighting system has presence sensors, so as you walk or bicycle through the park, the way/street lighting turns on, you can walk, and just after you, it turns dark again. Really cool, especially the first time I went through it in the mid…
Wouldn't it be more reasonable to just expect people who want to walk places in the dead of night to wear a headlamp? They're cheap, easy to recharge, and can be adjusted for various brightness levels.
Re: LEDs’ potential to save our night skies
#20> Thorp notes that modern CCTV cameras are “pretty great” even at low-light levels, while harsh light makes it hard for both human eyes and digital sensors to see. That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system”
> That’s a weird thing to include. That sounds like an argument _for_ more aggressive lights. I didn’t expect to see a “think of the surveillance system” One of the biggest excuses for ultra-bright streetlights is crime prevention (usually shortly followed by CCTV). I'm not really sure why we continue to indulge that point of view, but if one is indulging it...
The "lights=safety" nonsense shows no sign of coming to an end. Many private residences also install eye-searing levels of lighting outside that they just leave on all night, which is much cheaper to do now thanks to LED technology. There's really no reason for doing it. The idea it deters crime is a long-standing myth (someone analogous to the idea CCTVs deter crime).