I've been watching some of the neighborhoods undergo early adoption of LED street lamps. It's been interesting.
The new lamps are definitely much bluer than the current sodium lights, which gives the street a different, unfamiliar feel. The article suggests the city ultimately adopted 3000K lamps, but it definitely feels like the pilot program used 4000K ones, they looked very cool.
Another interesting development with these so-called "smart lights" [1] is that the city can potentially modulate brightness on a street-by-street basis, and asking different neighborhoods to weigh in on where they want the lamps to be brighter (or maybe, if they want them dimmer on side streets etc). This sounds like a very good change - customizing street lights based on neighborhood requirements is a very nice development!
All color considerations aside, one thing I find quit discomforting (first subconsciously, until I put my finger on it, and now even worse) is that led lights are very very often a rectangular array of lighting elements. So instead of a point (or at least a large diffuse, continuous "point" in various bulb constructions) there are between 25-64 points of light in a 6"x6" area. From a 20' light pole, looking at the shadow of your hand on the sidewalk, you see (let's say) 36 different vague shadows, in a rectangular array, with a disfigured hand shaped, darkest shadow in the middle where the shadows all overlap. Truly, it can be dizzying if you try to focus on the shape of the shadow from a single object. Tree canopies become shifting fields, everything gets a blocky 16bit feel to it. I'm only human, but I can imagine some animals are well tuned to single point shadows and this effect might really throw them off.
(Interesting aside, I first noticed this while leaving LACMA (LA County Museum of Art) where the pure Instagram gold of Chris Burden's collection of old LA street lamps tightly packed, produces the same effect)
But AFAIK LED brightness is usually controlled by pulse-width modulation, which is essentially adding flicker.
There are people with flicker sensitivity that have headaches when exposed to flickering light. A link to a HN discussion that touched the problem of PWM and flicker in the comments: https://news.ycombinator.com/item?id=13330611
In my subdivision in a metro Atlanta county I the local power cooperative is replacing failed halogen/sodium/etc street lamps with LED.
The orange lights provided good light but the same pole with a LED now lights up the area as if it were full moon or close to it. You cannot look directly at these lights where you could at the older lights. I have an orange lamp in the corner of my lot but the nearest LED is about three hundred feet away and it still puts out more.
One oddity which I cannot completely attribute to the lights. Birds in our holly bushes were singing at very odd hours for the first weeks or two but have apparently moved to bushes and trees in the back yard.
Yea I live on a street with the pilot program and no doubt they were much brighter than 3000K. They were very blue but I really like them. It gave my neighborhood a more small town feel if that makes any sense.
The difference on the ground is quite noticeable, partly because we're so used to sodium yellow and as LEDs are in the 6000K range - i.e. daylight ... it's 'uncanny', things certainly seem more HD - here's a picture I recently took at night:
The white LEDs make me think of housing projects since they often have brighter non-sodium flood lights (to deter mischief ), in contrast to the next block over which would have sodium.
What I wonder is: ok, so LED ligts save a lot of energy, which is great. But do they all have to be #FFFFFF white? Given that there's LEDs in all colours, would it be much more expensive to build/ buy/ run e.g. orange LEDs?
As all these cities convert to LED, not a single one is remembering one of the big advantages of sodium lights on the environment -- it's better for the animals. A lot of animals navigate by moonlight. When it looks like there is a moon every 50 ft, that really screws them up.
Not to mention how bad it is for humans. I installed a bunch of 1850K lights in my house as well as f.lux on my computer and night watch on my phone. After 11pm, I try to avoid any light above 1850K at all costs.
And it has worked. I sleep a lot better since I went "all 1850". But when I have to drive late at night, it screws that all up.
Many neighbourhoods did not convert to sodium lights until the 70s and 80s.
For the better part of the 20th century we used mercury-vapor street lights, which bathed the streets in soft blue light. The complete lack of red wavelengths in these lights would make a red car look black, and made humans look like vampires.
Current versions of LED streetlamps are absolutely awful. They have very high blue glare which is not only momentarily distracting in peripheral vision and disruptive of sleep cycles but also totally wrecks your night vision. It doesn’t help that they are often turned up to several times brighter than necessary. Same goes for LED car headlamps (especially on SUVs), which should be regulated right off the road. After San Francisco installed some awful LED lamps on my street, I’ve taken to wearing orange safety glasses when I walk my dog, and if I had to drive with any regularity I would consider wearing orange glasses to drive at night.
The excuse I’ve heard that “these are the same color as moonlight” is total nonsense. We don’t have 10 moons hanging 20 feet off the ground on every city block. Nighttime is not supposed to look like daytime. People are not supposed to be reading novels in the street at night, or critically examining the colors of paintings.
Moreover, much of the efficiency story is exaggerated. Recent types of high-pressure sodium lamps are very efficient. The big advantage LEDs have is that they (theoretically) don’t need to be replaced as often. We’ll see how it goes in practice over the coming decades.
The real story of course is that lighting companies have made a big marketing push, and from what I understand there is state/federal grant money available for new LED lighting projects (which are sold as “environmentally friendly”, etc.).
If cities want to use LED street lamps, they should be <3000K correlated color temperature, with as little blue light as possible. They should include diffusers, should be shielded to not shine in the eyes of pedestrians or drivers who aren’t intentionally looking upwards, should be spaced closely enough together that there isn’t a huge contrast between patches of dark and light going down the street, and should be set to a reasonable brightness. Human rod vision is incredibly adaptable to seeing in very dark situations.
I remember when the sodium vapors started deploying. Ugh... a fairly common reaction, at the time.
So, this may be a "change." But it's a change away from a few decades of orange.
One thing I wonder, is whether they will continue to deliberately "light everything", or whether they will implement some tuning to restrict lightflow to more relevant areas.
It isn't just street lighting. In places like Chicago, they've chosen in many areas to make that light as much as possible a seamless and universal presence. It doesn't just illuminate the streets and walkways. (Because crime, is the primary rhetoric around this.)
P.S. One difference between the sodium vapor (and before them, the mercury vapor) lights and the new LED lighting, is that the former hang down within a diffuser. This makes it easy to have illumination up to the second story windows. The LED lights I've seen have the LED's within or at the edge of the overhead hood. I wonder whether such broad illumination is as readily achieved with them. Also, the LED's are very bright pinpoints of light. Especially if they are going to go for "illuminate everything," this could make looking down the street kind of uncomfortable. I, for one, do my best not to look at those bright spots -- they are painfully bright, and I even worry about vision damage.
a new building development put up LED lights and its awful. I cant open my curtains without having piercing white like come in. its hard to explain, its not like a spot light is on the window, but it hurts my eyes even when its hitting the peripherals.
San Jose also uses orange sodium lights to help reduce light polution for the Lick Observatory.
I agree with the article they have a "gloomy" effect. They are also pretty much the exact same color as the yellow in traffic signals, which can make driving at night a tad more annoying.
Light pollution is another important side aspect of this. What if, as light becomes cheaper, people/ cities just use more of it? From other comments, it sounds like this is already happening with LED.
The'll probably want to switch to the LED lights then. They produce any light pollution compared to the orange sodium lights. The difference is quite startling.
I would definitely get tested for colour blindness. At least in the three cities where I have regularly driven over the last 20 years, the colours are distinctly different.
OT: When I was kid I remember that all cars in Paris had yellow front lights which gave the city a special and unfamiliar look. Is this still the case?
Edit: Just googled myself, it's called Selective Yellow[1] and the reasons are interesting and depending on the source different [1][2].
A large institution I'm aware of that installed thousands of these lights in indoor and outdoor public spaces during the recession. The hook, which was a ROI written by the lighting companies and fed to the facility people indicated that the lights would save some ridiculous amount of money, factoring in fewer bulbs, fewer service calls, etc. The reality is that total cost is only marginally better.
The problems are twofold -- the lights don't last as long as advertised, particularly in enclosed fixtures. Warranty claims are difficult, and they cost 7-12x the legacy bulb. In reality, they are spending more than they did with legacy bulbs because they need to dispatch people when they (frequently) break vs. do scheduled maintenance.
The other issue is that new bulb tech is harder to buy thanks to the carnival marketplace. Legacy bulbs involved a janitor looking up a part number written on the fixture. Exceptions were limited -- exhibit space needed a fancier bulb. The new stuff has different color temps, intensities, etc that nobody understands and many people disagree about.
I'm skeptical about cost savings in these programs. If there are cost savings, my guess is that the savings is stemming from the "managed service" model that the vendors push (i.e. Contractors making $20/hr, vs a $45/hr city worker) and less from the electric bill.
I'm curious if anyone has tied the recent talk about different hues of light and their effect on human health and citywide lighting? I'm referring to the types of stuff Dave Asprey and bulletproof people talk about. Could you influence the community as a whole through lighting choices?
The larger problem with newer headlights isn't so much the HID or LED source, but the fact that nearly all cars are coming with projectors. Even halogen looks really bright to oncoming traffic when it's focused down to come out of a small-diameter source. I would be interested to see what we could do with lower power LEDs in an array -- same or more light actually hitting the road, but potentially much less glare to oncoming drivers.
Seems like household bulbs are either too yellow or too blue/white. Our choices are now dim yellow or harsh unnatural white. For me, the GE Reveals and old "standard" bulbs were perfect.
It literally changes the colors we see in our environment. Always took colors/lighting for granted until the war on incandescents.
Sao Paulo's former mayor Fernando Haddad's popularity took a plunge as soon as he announced that he was replacing all conventional bulbs with LED. The population thought that was a step backwards and instead elected the host of the Brazilian version of "The Apprentice". Sound familiar?
The sodium lamps never really caught on where I live, but we had the pleasure of them along a few select stretches of motorway, though by now they are long gone.
I liked them. Pleasant for night driving, easy on the eyes, and not blending in with everything else.
I image I would like them even more today. Eyesight fine, but dammit, with age you start loosing contrast after sunset. Driving the city at night, especially in rainy weather, gets really tiring after a while. And the headlights on newer cars seem to be in fierce competition of unpleasant blue harshness.
Several years ago this was a big issue in Los Angeles for filmmakers - there was a distinct look that people expected from a night scene in Hollywood, sunset, or pretty much anything in LA. Filmmakers would hunt down the last few neighborhoods to switch and film there before the streetlights turned blue.
Now to get the same effect, you've got to provide your own lighting.
I never understood why westerners like orange light. I find it depressing. The same goes for the lights at home. I make a point of always replacing the 2700k bulbs with something whiter.
Are there any EEs on HN who can explain a characteristic failure mode of LED lamps---as well as LED-lit commercial signs---that very bright, metronomic 2--5 Hz flashing that they do? I've seen it happen to street lamps, desk lamps, commercial signage, traffic signals...it's not the usual 50 or 60 Hz flicker, but a distinct failure mode, regularly flashing a few times a second, like a circuit breaker resetting, but faster.
It's distinctive to LEDs, must be something in the power supply. But why do so many LED lamps do it?
[+] [-] 60654|9 years ago|reply
The new lamps are definitely much bluer than the current sodium lights, which gives the street a different, unfamiliar feel. The article suggests the city ultimately adopted 3000K lamps, but it definitely feels like the pilot program used 4000K ones, they looked very cool.
Another interesting development with these so-called "smart lights" [1] is that the city can potentially modulate brightness on a street-by-street basis, and asking different neighborhoods to weigh in on where they want the lamps to be brighter (or maybe, if they want them dimmer on side streets etc). This sounds like a very good change - customizing street lights based on neighborhood requirements is a very nice development!
[1] https://www.cityofchicago.org/city/en/depts/cdot/supp_info/c...
[+] [-] abcanthur|9 years ago|reply
(Interesting aside, I first noticed this while leaving LACMA (LA County Museum of Art) where the pure Instagram gold of Chris Burden's collection of old LA street lamps tightly packed, produces the same effect)
[+] [-] inlineint|9 years ago|reply
There are people with flicker sensitivity that have headaches when exposed to flickering light. A link to a HN discussion that touched the problem of PWM and flicker in the comments: https://news.ycombinator.com/item?id=13330611
[+] [-] Shivetya|9 years ago|reply
The orange lights provided good light but the same pole with a LED now lights up the area as if it were full moon or close to it. You cannot look directly at these lights where you could at the older lights. I have an orange lamp in the corner of my lot but the nearest LED is about three hundred feet away and it still puts out more.
One oddity which I cannot completely attribute to the lights. Birds in our holly bushes were singing at very odd hours for the first weeks or two but have apparently moved to bushes and trees in the back yard.
[+] [-] pducks32|9 years ago|reply
[+] [-] supernumerary|9 years ago|reply
Regarding a city that's already done this - Detroit went full LED this year:
http://www.mlive.com/news/detroit/index.ssf/2017/01/led_ligh...
The difference on the ground is quite noticeable, partly because we're so used to sodium yellow and as LEDs are in the 6000K range - i.e. daylight ... it's 'uncanny', things certainly seem more HD - here's a picture I recently took at night:
https://iainmait.land/img/photos/1280/street_crossing_2_2017...
[+] [-] klipt|9 years ago|reply
[+] [-] jessriedel|9 years ago|reply
[+] [-] mustacheemperor|9 years ago|reply
The OP article is about how Chicago is using 3000k lights so they're warmer - the cooler option was 4000k.
[+] [-] f_allwein|9 years ago|reply
What I wonder is: ok, so LED ligts save a lot of energy, which is great. But do they all have to be #FFFFFF white? Given that there's LEDs in all colours, would it be much more expensive to build/ buy/ run e.g. orange LEDs?
[+] [-] jedberg|9 years ago|reply
Not to mention how bad it is for humans. I installed a bunch of 1850K lights in my house as well as f.lux on my computer and night watch on my phone. After 11pm, I try to avoid any light above 1850K at all costs.
And it has worked. I sleep a lot better since I went "all 1850". But when I have to drive late at night, it screws that all up.
[+] [-] thought_alarm|9 years ago|reply
For the better part of the 20th century we used mercury-vapor street lights, which bathed the streets in soft blue light. The complete lack of red wavelengths in these lights would make a red car look black, and made humans look like vampires.
The animals and the humans will be just fine.
[+] [-] ericd|9 years ago|reply
[+] [-] nwah1|9 years ago|reply
[+] [-] blurrywh|9 years ago|reply
Which is also good, so you stay awake when driving.
[+] [-] Baeocystin|9 years ago|reply
[+] [-] jacobolus|9 years ago|reply
The excuse I’ve heard that “these are the same color as moonlight” is total nonsense. We don’t have 10 moons hanging 20 feet off the ground on every city block. Nighttime is not supposed to look like daytime. People are not supposed to be reading novels in the street at night, or critically examining the colors of paintings.
Moreover, much of the efficiency story is exaggerated. Recent types of high-pressure sodium lamps are very efficient. The big advantage LEDs have is that they (theoretically) don’t need to be replaced as often. We’ll see how it goes in practice over the coming decades.
The real story of course is that lighting companies have made a big marketing push, and from what I understand there is state/federal grant money available for new LED lighting projects (which are sold as “environmentally friendly”, etc.).
If cities want to use LED street lamps, they should be <3000K correlated color temperature, with as little blue light as possible. They should include diffusers, should be shielded to not shine in the eyes of pedestrians or drivers who aren’t intentionally looking upwards, should be spaced closely enough together that there isn’t a huge contrast between patches of dark and light going down the street, and should be set to a reasonable brightness. Human rod vision is incredibly adaptable to seeing in very dark situations.
[+] [-] mattbettinson|9 years ago|reply
[+] [-] pasbesoin|9 years ago|reply
So, this may be a "change." But it's a change away from a few decades of orange.
One thing I wonder, is whether they will continue to deliberately "light everything", or whether they will implement some tuning to restrict lightflow to more relevant areas.
It isn't just street lighting. In places like Chicago, they've chosen in many areas to make that light as much as possible a seamless and universal presence. It doesn't just illuminate the streets and walkways. (Because crime, is the primary rhetoric around this.)
P.S. One difference between the sodium vapor (and before them, the mercury vapor) lights and the new LED lighting, is that the former hang down within a diffuser. This makes it easy to have illumination up to the second story windows. The LED lights I've seen have the LED's within or at the edge of the overhead hood. I wonder whether such broad illumination is as readily achieved with them. Also, the LED's are very bright pinpoints of light. Especially if they are going to go for "illuminate everything," this could make looking down the street kind of uncomfortable. I, for one, do my best not to look at those bright spots -- they are painfully bright, and I even worry about vision damage.
[+] [-] autokad|9 years ago|reply
[+] [-] city41|9 years ago|reply
I agree with the article they have a "gloomy" effect. They are also pretty much the exact same color as the yellow in traffic signals, which can make driving at night a tad more annoying.
[+] [-] f_allwein|9 years ago|reply
[+] [-] cornchips|9 years ago|reply
I've never observed street light color making driving at night annoying; for the 3-5 second interval the yellow is on.
Just curious, have you ever been tested for color blindness?
[+] [-] eikenberry|9 years ago|reply
[+] [-] unknown|9 years ago|reply
[deleted]
[+] [-] ojiikun|9 years ago|reply
[+] [-] blurrywh|9 years ago|reply
Edit: Just googled myself, it's called Selective Yellow[1] and the reasons are interesting and depending on the source different [1][2].
[1] https://en.wikipedia.org/wiki/Selective_yellow
[2] http://www.french-cars-in-america.com/why-did-france-have-ye... https://www.tripadvisor.com/ShowTopic-g187147-i14-k711979-Ye...
[+] [-] fphilipe|9 years ago|reply
[+] [-] agumonkey|9 years ago|reply
[+] [-] Spooky23|9 years ago|reply
The problems are twofold -- the lights don't last as long as advertised, particularly in enclosed fixtures. Warranty claims are difficult, and they cost 7-12x the legacy bulb. In reality, they are spending more than they did with legacy bulbs because they need to dispatch people when they (frequently) break vs. do scheduled maintenance.
The other issue is that new bulb tech is harder to buy thanks to the carnival marketplace. Legacy bulbs involved a janitor looking up a part number written on the fixture. Exceptions were limited -- exhibit space needed a fancier bulb. The new stuff has different color temps, intensities, etc that nobody understands and many people disagree about.
I'm skeptical about cost savings in these programs. If there are cost savings, my guess is that the savings is stemming from the "managed service" model that the vendors push (i.e. Contractors making $20/hr, vs a $45/hr city worker) and less from the electric bill.
[+] [-] forgotpwtomain|9 years ago|reply
[0] https://www.ncbi.nlm.nih.gov/labs/articles/27751961/
Was discussed on HN previously: https://news.ycombinator.com/item?id=13330611
[+] [-] brianbreslin|9 years ago|reply
[+] [-] droidist2|9 years ago|reply
[+] [-] prmph|9 years ago|reply
[+] [-] rootusrootus|9 years ago|reply
[+] [-] goda90|9 years ago|reply
[+] [-] unclebucknasty|9 years ago|reply
It literally changes the colors we see in our environment. Always took colors/lighting for granted until the war on incandescents.
[+] [-] jseliger|9 years ago|reply
Funny you should mention that. I just wrote this: http://kk.org/cooltools/finally-led-light-bulb/ a few days ago. This bulb has a yellow-pinkish hue and I think it's great.
[+] [-] jacobolus|9 years ago|reply
[+] [-] caiob|9 years ago|reply
[+] [-] interfixus|9 years ago|reply
I liked them. Pleasant for night driving, easy on the eyes, and not blending in with everything else.
I image I would like them even more today. Eyesight fine, but dammit, with age you start loosing contrast after sunset. Driving the city at night, especially in rainy weather, gets really tiring after a while. And the headlights on newer cars seem to be in fierce competition of unpleasant blue harshness.
[+] [-] djrogers|9 years ago|reply
Now to get the same effect, you've got to provide your own lighting.
[+] [-] hyperion2010|9 years ago|reply
[+] [-] hasenj|9 years ago|reply
[+] [-] kingmanaz|9 years ago|reply
[+] [-] tptacek|9 years ago|reply
[+] [-] secabeen|9 years ago|reply
[+] [-] thefalcon|9 years ago|reply
[+] [-] mercer|9 years ago|reply
[+] [-] jloughry|9 years ago|reply
It's distinctive to LEDs, must be something in the power supply. But why do so many LED lamps do it?