I wrote an article about this almost a year and a half ago, and I was wondering how it's held up. I think Scientific American is remiss in not digging a bit deeper, because to me one of the main parts of this story is a commercial phenomenon - street lighting in the US is pretty monopolized, almost all municipal street lights and a good portion of area lights are made by the same company (Acuity). That makes it a lot less surprising that they would exhibit a similar failure around the same time.
Acuity has acknowledged a phosphor defect in their lights and had launched a major warranty repair campaign, but I'm not sure how well that's gone given that new failures are still occurring. At least a year ago, they were struggling with the scale of the problem: it just takes a long time to schedule replacement of failed fixtures when there are so many of them.
kuon 1 hours ago [-]
It is not directly related to the article, but the decaying LEDs mentionned in the article made me think of it.
Since we had to switch to LEDs, I had to change lightbulbs waaay more often. I realize they consume less (even if here they would just help heat the house so the energy is not lost), but hell they are crap. They start blinking, their color is shifting, they die quickly, they are super expensive, they are bigger and many lamp I had couldn't be fitted with LEDs unless I found some smaller ones which are even more expensive.
This is my personal anecdotal experience, but I would be interested if any serious study had looked into this kind of issues.
userbinator 43 minutes ago [-]
Phoebus Cartel 2.0
bertm 4 hours ago [-]
A friend and I found a contractor to give us a couple of these lights in the Phoenix area. We traced the LEDs back to a Seoul Semiconductor Phosphor on-chip design. We still have a suspicion that LM80 testing didn’t catch this and it was due to a thermal cycling failure. https://m.youtube.com/watch?v=4Mll-YDDAF4
modeless 15 hours ago [-]
> people driving at night may notice a moving object in their peripheral vision more quickly under bluish-white light than under yellowish-white light, [...] Gaining improved peripheral vision under blue-tinged light comes with a trade-off, however: once the moving object comes into focus, it becomes harder to see.
If we were switching away from LED to sodium vapor lamps instead of the other way around, they would have written the exact same article but in reverse, still claiming the change makes us less safe.
PedroBatista 14 hours ago [-]
No, sodium vapor lights offer great performance in terms of contrast and visibility. Especially in bad weather conditions.
robertlagrant 14 hours ago [-]
Yes but that's the point: sodium vapour offers worse peripheral vision, so it could make some situations riskier.
metalman 13 hours ago [-]
no way, once something is into your periferal vision while in a moving car it's too late, and fact does not matter....unless it's moving realy realy fast, and then it's still too late
so the real equation will involve all sorts of other inputs, like the coulor temp, and amount of direct vs reflected light, background light conditions, weather, and indivual perception of any given driver.
*green light is the worst, as our eyes have the greatest sensitivity to it, and out night vision adaptation is to the black and white(muted coulor)
light that is natural.
current regulations are ancient, but there is no reason that a non opiniated solution cant be figured out and implimented
quietbritishjim 6 hours ago [-]
> once something is into your periferal vision while in a moving car it's too late, and fact does not matter.
When you're looking up in your rear view mirror, your view of the road ahead is from your peripheral vision. It most definitely does matter.
pxc 3 hours ago [-]
Higher contrast isn't strictly better. Street lights where I live are deliberately sparse to limit light pollution, but this means that some of them are sometimes too bright— since the whole road isn't suffused evenly with light, very bright lights are somewhat blinding, especially to light sensitive people.
14 hours ago [-]
neilv 4 hours ago [-]
As someone who walks a lot (including, for many years, back late at night from work or school), I really wish they'd made the LED streetlights approximate the original warm color temperature from the start.
Instead of going bright white, high-color-rendition, wake-up-and-kiss-your-sleep-schedule-goodbye, which is what they went with instead.
When the LED streetlights were first installed, they were horrible, and we were promised they would be adjusted, but they never were sufficiently.
Maybe caring about the look of neighborhoods, and the sleep of people who walk or have unfortunate bedroom window positions, would've had a side effect of avoiding the problem in the article?
Zak 4 hours ago [-]
There are 1800K white LEDs as well as phosphor-converted amber made to approximate the look of the classic amber low-pressure sodium.
1800K white can render colors surprisingly well depending on the phosphor mix. I recently put one with claimed (and measured) CRI over 90 into a flashlight and was surprised to see that it actually can render blues reasonably well.
I'm inclined to think those are better choices for street lights than anything daylight-ish, but I also think we should use far fewer street lights. Their presence often reduces the contrast car headlights provide, making it harder to spot hazards while driving.
StrangeDoctor 3 hours ago [-]
Each CRI is referenced to an ideal black body radiator at the same temp below 5000k. And there are 7 (or 14) sample points.
I’m not disagreeing with you, I agree that a high cri 1800k would be a nice night light. I just recently deep dived into this last week when my kitchen lights all died last week
ChrisMarshallNY 3 hours ago [-]
The main issue that I have with LED lights, is that they are very coherent, so the brights are brighter, but the darks are darker.
This can easily be seen by looking at the shadows under an LED streetlamp, compared to a metal halide one. The LED shadows are very sharp.
hollerith 4 hours ago [-]
I've started wearing blue blockers when going out at night.
neilv 4 hours ago [-]
Which is why this part of the article was the frustrating icing on top:
> One thing that Bullough suggests pedestrians and drivers do to stay safe under purple streetlights—or any lights, for that matter—is to remove sunglasses and blue-light-filtering glasses when walking or driving at night.
I had someone complain to me about how it was a change made by the Green Party for bats: how ridiculous!
No, it’s just a faulty light…
msgodel 14 hours ago [-]
I was told it was to make it hard for people using needles to find their vanes. It turns out it's just the phosphor coating coming apart. The LEDs used to energize that to make the broad spectrum light are usually blueish purple for maximum efficiency.
cogman10 14 hours ago [-]
It does do that and it's used for that.
I first experienced that in a bathroom in England. Door open, regular white light. Lock the door, blue light. I thought I broke something when that happened.
jamiek88 4 hours ago [-]
Makes the cocaine easier I see too! Social economic apartheid for the win!
guicen 14 hours ago [-]
It’s interesting how many people assume these purple lights are some kind of new design choice. But really, it’s just a side effect of the phosphor layer breaking down in the LEDs.
Makes you appreciate how tricky it is to balance cost, lifespan, and quality when you’re manufacturing millions of these for cities.
ankitml 6 hours ago [-]
Design choices must include failure modes. IMHO, utterly stupid to only consider happy path.
I've never seen a LED streetlight turn people where I live. Sounds like bad light design and the LED is perhaps getting too hot.
Though that said, just go and replace them as they would have had to for sodium vapour lamps they had before? And this time replace them with something that runs them at a lower temperature, especially if the environment during a summer could be hot from external temperature.
flyinghamster 5 hours ago [-]
All of the purple lights I've seen have been of the same design, and they seem to be in towns that are (at least to some degree) cash-strapped. The manufacturer better be replacing these under warranty.
There aren't any of them in my town, though I've seen one LED streetlight so far that went out. The main streets have lights with a slight yellow tint, and the side streets are neutral white, which I find much more pleasing than the purplish mercury arcs they replaced.
joshstrange 15 hours ago [-]
> And yet some streetlights have suddenly turned a jarring shade of purple. It is hard to determine the exact cause without dissecting one of the defective lights, but scientists have a hypothesis: bright purple light suggests the phosphor layer around the lights has been “delaminated”—peeled off—exposing the blue LED light underneath, Brgoch says.
What an annoying/bad article. "Here are our guesses of this when we could have actually figured it out". It's not like these are in space and hard to get to, they are on the freaking street. Get a crew out there and figure it out.
Then they go on to do a _bunch_ of handwavy "science" about blue light while not really making any point (IMHO).
> One thing that Bullough suggests pedestrians and drivers do to stay safe under purple streetlights—or any lights, for that matter—is to remove sunglasses and blue-light-filtering glasses when walking or driving at night.
Ahh yes, for all the people that wear their sunglasses at night, I'll make sure to let Corey Hart know.
This just seems like an incredibly low-effort article with zero definite facts and enough hand waving to sprain your wrist.
neutronicus 15 hours ago [-]
FWIW I do wear sunglasses for long highway drives at night.
Without them halogen headlights in my side mirrors give me a migraine after a while.
jessriedel 14 hours ago [-]
FYI you can get auto-dimming side mirrors (same mechanism as for rear-view mirrors). I presume it’s a pain to install them after-market, but it can be done and maybe worth it for you if brights bother you enough to wear sunglasses.
sokoloff 5 hours ago [-]
When I had some window tinting done on a car, they tinted the side mirrors at no extra charge with excess film.
At first, I didn’t like it, but quickly grew to quite like it. (It’s pretty much only annoying for seeing the curb while parallel parking at night.)
jessriedel 2 hours ago [-]
I don't think tinting is the same thing as electronic dimming.
kayodelycaon 14 hours ago [-]
I’m not sure if someone has dissected them to see what’s wrong and published the results.
Deductive reasoning points to a failure of the phosphor layer in a specific type of led.
1970-01-01 6 hours ago [-]
Someone did, it's accurate to state this is published work
I mean, to be fair, the city maintenance crews don't generally run tear-down youtube channels with appropriate equipment to take a close look at a failing semiconductor-based light assembly.
But the general point is correct. What could be done is connect with some of those crews' offices, understand what warranties are provided with the municipal purchase of those bulbs, and how much comes out of the infrastructure budget to do an early replacement of these bulbs. Hopefully these bulbs weren't purchased from a RANDOMSYLLABLE amazon china dropshipper who disappeared after 3 months.
But yes, that requires talking to municipal governments, and there's not enough click revenue to support that level of journalism anymore.
Maybe a youtuber who runs a tear-down channel can do that.
bob1029 14 hours ago [-]
> Hopefully these bulbs weren't purchased from a RANDOMSYLLABLE amazon china dropshipper who disappeared after 3 months.
This is how most LED bulbs in use today are purchased. In theory, LED is absolutely superior when engineered correctly, but it rarely is on a statistical basis when looking at the available products.
It's hard to make an incandescent bulb that is shitty, other than making it not last for a very long time. I'd rather a dead bulb than one that turns my street into a nightclub.
cootsnuck 4 hours ago [-]
There's multiple adjacent parking lots in my city that are full of street lights that emit blue light. I've been wondering for awhile why in the world they would be blue but I think I got my answer. Probably someone trying to cut costs a bit too aggressively. My city and state are known for skimping on anything and everything when it comes to streets and roads.
relwin 6 hours ago [-]
My LCD TV did the same thing with a few of the backlight LEDs. Makes a big purplish splotch on the screen. Replaced the backlight strips and took the lens off of one of them and was surprised how small the LED is -- tiny yellow 1.5mm squares.
keepamovin 3 hours ago [-]
Trade-off-aware software engineers discussing streetlight variant choices is the infinite loop of endless discussion.
rtkwe 3 hours ago [-]
We had some of these on my street. Honestly liked them better than the full power ones they got replaced with.
rco8786 3 hours ago [-]
An apartment building a few blocks over from me has these. It makes the whole area look like a night club. Very weird.
hackernoops 3 hours ago [-]
Glad I converted nearly all of the lights in my house to halogen, and stocked up on decades of bulbs, before the ban. Nice warm adjustable light. No strobing LED trash fucking up my eyesight.
frosted-flakes 1 hours ago [-]
Incandescent lights are still widely available if you still want them. Nonetheless, modern high quality LED lights can actually exceed the colour rendering index of incandescent lights, though they tend to be a little more expensive. I don't think it's a big deal to pay $15 for a bulb that will still be there in 15 years.
dtgriscom 3 hours ago [-]
I'm the opposite; glad to have all LEDs. Cool, dimmable, and energy efficient.
davidmurdoch 14 hours ago [-]
Read somewhere a few years ago this was a manufacturer defect and they were in the hook for replacing them all.
I've (not seriously) considered buying a pellet gun to shoot out the 4 massive neon purple lights at the entrance to my quaint 1970s era neighborhood. They didn't remove the old light poles after installing the new ones about 3 years ago, so it's double lit with sodium vapor and purple now.
Curious is there is a single person on the planet that prefers the white (er, purple) street lights?
malfist 14 hours ago [-]
Single wavelength light is easier to remove or filter out for astrophotography than broad-spectrum light.
But driver safety is probably way more important than my hobby
worik 3 hours ago [-]
> Curious is there is a single person on the planet that prefers the white (er, purple) street lights?
Yes
One at least, me
(I've never seen this failure mode, so I mean the LEDs)
I especially like the reduction in light pollution
davidmurdoch 3 hours ago [-]
I don't understand, you prefer the new LED lights but also like reduction in light pollution? The LEDs way brighter, so I'd think you'd prefer older lights.
I'd guess about 20% of the lights in and around Orlando are purple now. Maybe the heat and UV makes it worse here?
kragen 14 hours ago [-]
I haven't tried them, but they sound awesome.
CalRobert 15 hours ago [-]
“ producing light that is comparable or better in quality.”
They don’t support this claim about led’s, and many groups are concerned about harsh cool light interrupting circadian rhythms. They’re also hideous.
BorgHunter 15 hours ago [-]
It depends strongly on implementation. LEDs can produce white light at any color temperature and CRIs ranging from terrible to great. Quality LEDs are quite nice indeed (when they're not turning purple).
Most LED streetlights replaced sodium vapor lights, though, which produce the sickliest, most horrible orange color known to humanity. Just about any LED is an improvement over those.
goku12 14 hours ago [-]
Strange! I was going to say the exact opposite. I find the near-white light from LEDs very harsh and tiring to my eyes. I often end up rubbing my eyes under them. The sodium orange feels cooler and easier. The strain on my eyes is similar to daylight, but without the alertness it induces. (White LEDs actually feel worse than daylight, for some reason)
There were articles a few years back stating that the blue emissions from these LEDs were rather energetic and damaging to the retina. Conversely, some articles used to claim that red light actually improves the health of the retina. I don't know if those results were corroborated or debunked afterwards.
I know that personal beliefs and biases affect our perceptions. But such diametrically opposite experiences are surprising. I'm curious to know what everyone else experiences and any insights on this.
Lammy 6 hours ago [-]
> Quality LEDs are quite nice indeed
This is true but irrelevant when cost reduction is the motivating factor for switching to LED lighting, because that motivation will extend to the upfront purchase cost of the lamps and they will buy whatever is cheapest.
hedora 15 hours ago [-]
Sodium lights aren’t even orange in the normal sense of the word. They only emit one wavelength.
addaon 14 hours ago [-]
> Sodium lights aren’t even orange in the normal sense of the word. They only emit one wavelength.
It's hard to think of a more normal sense of the word "orange" than "emitting and/or reflecting predominantly wavelengths between 590 and 620 nm." I guess you could argue that sodium is close enough to that lower edge to be yellow?
looofooo0 14 hours ago [-]
What is the normal sense of the word? I only know the CIE standard observer to define colour and with this it is clearly in the equivalence class of orange.
lukas099 14 hours ago [-]
I think they mean they don't emit a "natural" orange (like an orange flower) that is really some kind of sum of many wavelengths. I could be wrong though.
wiredfool 14 hours ago [-]
I thought it was two - the sodium double emission line.
xattt 14 hours ago [-]
If orange was tolerated before, I am curious why orange LEDs aren’t being looked at again for resilience.
looofooo0 14 hours ago [-]
Well we cannot manufacture orange LEDs with good efficiency.
anonnon 14 hours ago [-]
LED headlights are much bigger problem. Way too bright, way too blue.
SoftTalker 4 hours ago [-]
Both are problems. LEDs are terrible for white light.
quickthrowman 14 hours ago [-]
LED fixtures with a high CRI (90+), a proper lumen package, and color temperature are indistinguishable from incandescent lights.
Unfortunately, most pole lights are 70CRI, too bright, and the light is too white (4000K+).
Sunspark 14 hours ago [-]
The wavelengths are spiky compared to incandescent, and the LEDs flicker if they are not DC-driven.
The flicker is pretty annoying because the transition is an abrupt on-off. Where I am the city had the bright idea to wrap LED ribbons around the poles in the downtown area to make it look more interesting. They connected the ribbons without diffusers directly to the power source of the streetlight. So what has happened now is that as you drive or walk you are looking directly at an unshielded flickering LED.
I still continue to install incandescent bulbs. They look better, and as I live in a cold-weather country the heat they generate is welcomed.
Zak 4 hours ago [-]
It's possible to make an LED with a spectrum that is not very spiky, which a fan of incandescent light will likely enjoy. There is a cost to efficiency, which makes LED fixtures and screw-in bulbs with those traits specialty items. A color rendering index and R9 both in the high 90s is usually enough information to pick out such light sources.
Flicker is also not a given, but a product of using cheap rather than good methods to power LEDs starting from AC mains power.
chasil 14 hours ago [-]
"LED Filaments" are a more direct example of phosphor-coated blue.
Most everyone has seen these now, in "Edison Bulbs" or elsewhere.
This is happening everywhere where I live (Vancouver)
Daisywh 14 hours ago [-]
To be honest, I quite like this atmosphere. Some roads near my home now feel like something out of a science fiction movie when walked on at night. Of course, traffic safety may not be good, but walking at night adds a sense of fantasy.
RDaneel0livaw 15 hours ago [-]
one of the biggest roads in my town has these purple lights at night, and it's very off-putting honestly. Makes it kind of hard to see things properly. I specifically avoid this road at night now because of it.
worik 3 hours ago [-]
Wow!
The comments here!
Are we really such neo-phobe curmudgeons? Sodium hallide street lights preferred over LEDs?
Golly Hacker News, get a grip and join the modern world!
harimau777 3 hours ago [-]
We live in a late stage capitalist society. Anything new is almost always engineered to be lower quality in order to cut costs and extract more money from us.
echelon 15 hours ago [-]
Better article with lots of pictures and diagrams, links to conference talks, etc:
Thank you, this has been happening near me for years now and I've seen countless news articles on it, but this is the first time someone's actually linked what looks like an authoritative source (or at least anything that goes into more detail than "the phosphor is falling off... or something").
hoseja 15 hours ago [-]
This is wrong about phosphors in the initial explanation, no? They are actually quite broadband AFAIK.
A Trader Joe's in Phoenix has had these for so long (years?), the parking lot is bathed in almost completely blue light. They don't seem to care. It really throws off your vision and things look "fuzzy".
sidewndr46 15 hours ago [-]
Maybe it's just me but the actual color of the light never bothered me. The first time I saw it I figured out it was a form of LED failure. It's so common here that I don't think about it anymore
pxndxx 15 hours ago [-]
monochromatic light as emitted by LEDs is quite disorienting.
sidewndr46 15 hours ago [-]
I grew up in the generation where every manufacturer decided blinding bright blue LEDs were standard features of all consumer electronics. Maybe I am just desensitized to it?
Tldr “ bright purple light suggests the phosphor layer around the lights has been “delaminated”—peeled off—exposing the blue LED light underneath, Brgoch says. Although blue LED lights are, in principle, deep blue in color”
ribcage 14 hours ago [-]
[dead]
userbinator 3 hours ago [-]
I find it somewhat amusing that they had to find "scientists" to explain this, when the purple tinge is something that LED TV repairmen have been dealing with for around a decade now. However, they're correct that it's because the phosphor layer is getting damaged, probably because they're being driven too hard by the LEDs, which are now being optimised for brightness and recurring revenue instead of longevity and efficiency.
Also, I personally think spirited driving on a purple-lit nearly empty highway at night is a uniquely fun experience with an 80s-retro-futuristic vibe. The streetlights are merely accent lighting at that point; the highbeams are for actual visibility.
Acuity has acknowledged a phosphor defect in their lights and had launched a major warranty repair campaign, but I'm not sure how well that's gone given that new failures are still occurring. At least a year ago, they were struggling with the scale of the problem: it just takes a long time to schedule replacement of failed fixtures when there are so many of them.
Since we had to switch to LEDs, I had to change lightbulbs waaay more often. I realize they consume less (even if here they would just help heat the house so the energy is not lost), but hell they are crap. They start blinking, their color is shifting, they die quickly, they are super expensive, they are bigger and many lamp I had couldn't be fitted with LEDs unless I found some smaller ones which are even more expensive.
This is my personal anecdotal experience, but I would be interested if any serious study had looked into this kind of issues.
If we were switching away from LED to sodium vapor lamps instead of the other way around, they would have written the exact same article but in reverse, still claiming the change makes us less safe.
When you're looking up in your rear view mirror, your view of the road ahead is from your peripheral vision. It most definitely does matter.
Instead of going bright white, high-color-rendition, wake-up-and-kiss-your-sleep-schedule-goodbye, which is what they went with instead.
When the LED streetlights were first installed, they were horrible, and we were promised they would be adjusted, but they never were sufficiently.
Maybe caring about the look of neighborhoods, and the sleep of people who walk or have unfortunate bedroom window positions, would've had a side effect of avoiding the problem in the article?
1800K white can render colors surprisingly well depending on the phosphor mix. I recently put one with claimed (and measured) CRI over 90 into a flashlight and was surprised to see that it actually can render blues reasonably well.
I'm inclined to think those are better choices for street lights than anything daylight-ish, but I also think we should use far fewer street lights. Their presence often reduces the contrast car headlights provide, making it harder to spot hazards while driving.
I’m not disagreeing with you, I agree that a high cri 1800k would be a nice night light. I just recently deep dived into this last week when my kitchen lights all died last week
This can easily be seen by looking at the shadows under an LED streetlamp, compared to a metal halide one. The LED shadows are very sharp.
> One thing that Bullough suggests pedestrians and drivers do to stay safe under purple streetlights—or any lights, for that matter—is to remove sunglasses and blue-light-filtering glasses when walking or driving at night.
https://www.irishtimes.com/ireland/dublin/2025/02/05/almost-...
I had someone complain to me about how it was a change made by the Green Party for bats: how ridiculous!
No, it’s just a faulty light…
I first experienced that in a bathroom in England. Door open, regular white light. Lock the door, blue light. I thought I broke something when that happened.
Makes you appreciate how tricky it is to balance cost, lifespan, and quality when you’re manufacturing millions of these for cities.
Pretty interesting.
Though that said, just go and replace them as they would have had to for sodium vapour lamps they had before? And this time replace them with something that runs them at a lower temperature, especially if the environment during a summer could be hot from external temperature.
There aren't any of them in my town, though I've seen one LED streetlight so far that went out. The main streets have lights with a slight yellow tint, and the side streets are neutral white, which I find much more pleasing than the purplish mercury arcs they replaced.
What an annoying/bad article. "Here are our guesses of this when we could have actually figured it out". It's not like these are in space and hard to get to, they are on the freaking street. Get a crew out there and figure it out.
Then they go on to do a _bunch_ of handwavy "science" about blue light while not really making any point (IMHO).
> One thing that Bullough suggests pedestrians and drivers do to stay safe under purple streetlights—or any lights, for that matter—is to remove sunglasses and blue-light-filtering glasses when walking or driving at night.
Ahh yes, for all the people that wear their sunglasses at night, I'll make sure to let Corey Hart know.
This just seems like an incredibly low-effort article with zero definite facts and enough hand waving to sprain your wrist.
Without them halogen headlights in my side mirrors give me a migraine after a while.
At first, I didn’t like it, but quickly grew to quite like it. (It’s pretty much only annoying for seeing the curb while parallel parking at night.)
Deductive reasoning points to a failure of the phosphor layer in a specific type of led.
https://www.youtube.com/watch?v=4Mll-YDDAF4
I mean, to be fair, the city maintenance crews don't generally run tear-down youtube channels with appropriate equipment to take a close look at a failing semiconductor-based light assembly.
But the general point is correct. What could be done is connect with some of those crews' offices, understand what warranties are provided with the municipal purchase of those bulbs, and how much comes out of the infrastructure budget to do an early replacement of these bulbs. Hopefully these bulbs weren't purchased from a RANDOMSYLLABLE amazon china dropshipper who disappeared after 3 months.
But yes, that requires talking to municipal governments, and there's not enough click revenue to support that level of journalism anymore.
Maybe a youtuber who runs a tear-down channel can do that.
This is how most LED bulbs in use today are purchased. In theory, LED is absolutely superior when engineered correctly, but it rarely is on a statistical basis when looking at the available products.
It's hard to make an incandescent bulb that is shitty, other than making it not last for a very long time. I'd rather a dead bulb than one that turns my street into a nightclub.
I've (not seriously) considered buying a pellet gun to shoot out the 4 massive neon purple lights at the entrance to my quaint 1970s era neighborhood. They didn't remove the old light poles after installing the new ones about 3 years ago, so it's double lit with sodium vapor and purple now.
Curious is there is a single person on the planet that prefers the white (er, purple) street lights?
But driver safety is probably way more important than my hobby
Yes
One at least, me
(I've never seen this failure mode, so I mean the LEDs)
I especially like the reduction in light pollution
I'd guess about 20% of the lights in and around Orlando are purple now. Maybe the heat and UV makes it worse here?
They don’t support this claim about led’s, and many groups are concerned about harsh cool light interrupting circadian rhythms. They’re also hideous.
Most LED streetlights replaced sodium vapor lights, though, which produce the sickliest, most horrible orange color known to humanity. Just about any LED is an improvement over those.
There were articles a few years back stating that the blue emissions from these LEDs were rather energetic and damaging to the retina. Conversely, some articles used to claim that red light actually improves the health of the retina. I don't know if those results were corroborated or debunked afterwards.
I know that personal beliefs and biases affect our perceptions. But such diametrically opposite experiences are surprising. I'm curious to know what everyone else experiences and any insights on this.
This is true but irrelevant when cost reduction is the motivating factor for switching to LED lighting, because that motivation will extend to the upfront purchase cost of the lamps and they will buy whatever is cheapest.
It's hard to think of a more normal sense of the word "orange" than "emitting and/or reflecting predominantly wavelengths between 590 and 620 nm." I guess you could argue that sodium is close enough to that lower edge to be yellow?
Unfortunately, most pole lights are 70CRI, too bright, and the light is too white (4000K+).
The flicker is pretty annoying because the transition is an abrupt on-off. Where I am the city had the bright idea to wrap LED ribbons around the poles in the downtown area to make it look more interesting. They connected the ribbons without diffusers directly to the power source of the streetlight. So what has happened now is that as you drive or walk you are looking directly at an unshielded flickering LED.
I still continue to install incandescent bulbs. They look better, and as I live in a cold-weather country the heat they generate is welcomed.
Flicker is also not a given, but a product of using cheap rather than good methods to power LEDs starting from AC mains power.
Most everyone has seen these now, in "Edison Bulbs" or elsewhere.
https://en.wikipedia.org/wiki/LED_filament
The comments here!
Are we really such neo-phobe curmudgeons? Sodium hallide street lights preferred over LEDs?
Golly Hacker News, get a grip and join the modern world!
https://inside.lighting/news/24-05/heres-why-led-streetlight...
Also, I personally think spirited driving on a purple-lit nearly empty highway at night is a uniquely fun experience with an 80s-retro-futuristic vibe. The streetlights are merely accent lighting at that point; the highbeams are for actual visibility.