I remember reading here in Pittsburgh that the new street lights could be addressed individually or as groups and have their white points adjusted. I've never seen this in action and I haven't researched it further. But if they could be adjusted to be less blue, we'd still benefit from the energy savings.
Some cities are taking another look at LED lighting after AMA warning
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Re: Some cities are taking another look at LED lighting after AMA warning
#92Meanwhile, the “dark sky” movement criticizes LEDs as a major contributor to what it calls the “light pollution” that humans cast into the night sky. As a former, quasi-astronomer, nothing at night is more impressive than a star lit sky. My first night in Colorado was unbelievable.
Really? I thought one of the major advantages to LED street lighting is that it is much more directional, so it leaks less light into the sky.
20+ years ago, sodium (?, same as below?) lamps were suggested but supposedly people didn't like how things looked (IIRC) in the light.
http://www.flagstaffdarkskies.org/for-wonks/lamp-spectrum-li... says low pressure sodium lamps significantly improve star viewing compared w/ LED due to the narrower spectrum.
Downvote science, bitches.
Re: Some cities are taking another look at LED lighting after AMA warning
#93Earlier quoted context omitted.
What temperature LED light should I have for my bedroom?
I have a Philips sunrise alarm clock that looks like a lamp. I recommend that. It is a great lamp colour temperature and way to wake up.
I second this recommendation, although it is worth pointing out that they are not that bright even on full. Fine for going to bed but maybe not the only thing you want on a cloudy day. The sunset mode is really nice too, and I really really wish there was a way to hold at the pink color when it is nearly off. If you could get strips of that color to circle the room that would be excellent.
The flip side of lights that disrupt melatonin is that they can be good for you when you first wake up if natural light is not that strong in the morning where you are (or you aren't exposed to much of it when you first wake up).
Re: Some cities are taking another look at LED lighting after AMA warning
#94Earlier quoted context omitted.
The blue light also burns out retinae. It's been linked to cataracts. It seems like an industrial regulation is needed to me.
Citation? That's a bold claim. As phrased, it also sounds really far-fetched since cataracts are not a disease of the retina. Maybe that's a problem with the phrasing and not the claim, though.
just look up 'welders eye' or 'corneal flash burns' or 'photokeratitis'
high intensity UV light most certainly causes both corneal and retinal damage, both acute and as an ongoing effect over time.
i have never seen nor can i find any reference to visible blue light. i think* that heavily phosphored leds with high CRI and low color temp do emit quite heavily above visible and translate it down. so maybe there is some leakage?
Re: Some cities are taking another look at LED lighting after AMA warning
#95Yes! I am not crazy! Seriously, do we really need lights that make the city as light as in the day? I'd rather give my retinas a rest.
> as light as in the day It's got nothing to do with intensity, which would be impossible to achieve, for all practical purposes. The article misused the word here. Rather, it's about color temperature. I think this problem is overblown, because I've not heard similar complaints leveled against mercury-vapour lamps. I've grown up around them nearly all my life.
When you replace 1:1 vapor laps with LEDs an adequately lit parking lot becomes lit like a stage.
Though to your color temp point, if we could get lower color temperature that'd be great. IIRC red LEDs are much more efficient than full spectrum anyway.
Re: Some cities are taking another look at LED lighting after AMA warning
#96Let's break down their claims. > unseen blue light I have unread negative comments about this sloppy writing. They also repeatedly use the word "intense" incorrectly. Intensity refers to candela. Not lumens or temperature. > The original LED streetlights had temperatures of at least 4000K, which produces a bright white light with a high content of unseen blue light. 4000K is actually considered fairly mellow. Above 6…
> Moonlight is around 4100K. So it is even more "natural" than 3000K. Should we blot out the moon next? I was on a hike in July during a full moon and those who were sleeping in open air (no tent or bivy bag) struggled to sleep through the night due to the moonlight. This was in the North West of Australia, so daytime maximums were around 35C. It was too warm at night to zip your tent or bivy closed, so where possibl…
I sleep in a hammock on my balcony quite a bit and without covering your eyes it can be a real struggle when the moon is near full and the skies are clear. One thing mentioned elsewhere is the idea that darkness = safety. I can imagine that to be very true for humans.
Re: Some cities are taking another look at LED lighting after AMA warning
#97Earlier quoted context omitted.
Yes, I was a little glib. But nonetheless life on Earth (not just our species) evolved with a 4100K light source at night. You are confusing color temperature with how the lights are installed. If your streetlights were 4000K and spaced properly you wouldn't have an issue with them. The penny-pinching distribution (high lumens, wide angle, distantly spaced) of lights chosen by your city is at fault. That layout will…
> You are confusing ... I have spent 10 years studying color science. I know what color temperature is. I’m just explaining why the moon is a poor analogy. I have an issue with bright short-wavelength light sources at night, regardless of lamp configuration. It knocks out night vision. There is a wide literature (dozens if not hundreds of research papers) on this topic. It’s not exactly some deep mystery. The lamp co…
Do you mean that there are places where street lights with other technologies are replaced with LEDs by leaving every other lamp post empty?
That is a problem that LEDs could enable (by making very bright lamps available) but is not really a problem of LEDs but a problem of using any bright light source wrongly.
My understanding is that the use of lower-energy and more durable light sources provide most of the incentive to install new lamps. I.e. electricity bill is lower and you need to change the lamps less frequently which reduces maintenance cost.
Re: Some cities are taking another look at LED lighting after AMA warning
#98Wouldn't filters or rough refraction surface help offset the risks? Of course, I kind of feel that in climates with snowfall, the bulbs that generate heat are probably better for keeping said snow from building on the street lamps/lights.
Re: Some cities are taking another look at LED lighting after AMA warning
#99I had LEDs installed in the streetlight in front of my apartment in Brooklyn a few months ago and my living room is now awash with this light. It's terrible. I noticed my sleep time pushed further and further back and I've resorted to supplementing melatonin regularly so that I can fall asleep earlier than 2 am. I've complained to the city and have considered moving since I don't think NYC will swap ours back.
Please, put in blinds. If you have blinds, put in curtains to catch the light that spills around the blinds. If too much light goes through the blinds, upgrade to window shades. If that isn't enough (or you don't want to spend any money on interior decorating), get an eyemask. If $2 for an eyemask is too much, drape a t-shirt over your eyes. Moving is a comically inappropriate response.
If moving becomes a common response, we can use street lighting to fight gentrification. Don't discourage it.
Re: Some cities are taking another look at LED lighting after AMA warning
#100Let's break down their claims. > unseen blue light I have unread negative comments about this sloppy writing. They also repeatedly use the word "intense" incorrectly. Intensity refers to candela. Not lumens or temperature. > The original LED streetlights had temperatures of at least 4000K, which produces a bright white light with a high content of unseen blue light. 4000K is actually considered fairly mellow. Above 6…
My city used old-style mercury-vapor street lights up until the early 80s. For those who have never seen these lights, they have a bluish-white appearance but emit light only at a few very specific wavelengths, and almost none in the red spectrum. The effect is that under these lights a red car would look strangely black while everything else more or less looked normal color. I loved the effect. I have fond childhood…
These mercury-vapor lamps were used until 90-somethings where i used to live. People would say that until these bluish-white lamps were phased out by orange ones, people in the street would look as if they were dead; I would always counter with "they sure look as if they're alive now". Maybe because of childhood nostalgia I always preferred the bluish-white nights instead of that pervasive orange ones, especially during overcast winter nights where everything in thirty kilometer radius would become orange and unnatural. Clear nights with full moon were godsend.
But things are changing nowadays and our city also started using LEDs and by Moses, they are so much unbelievably better in all aspects! Even if they emit that "unseen blue" light, it is most definitely not worse than the insanely pervasive orange...