TL;DR - coating is wearing off.
The fix is incredibly simple https://www.youtube.com//watch?v=4Mll-YDDAF4&t=678
US Streetlights Are Turning Purple
21–30 of 122 posts
Re: US Streetlights Are Turning Purple
#22“ 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.
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+).
Re: US Streetlights Are Turning Purple
#23It’s a fairly common failure it seems. Here’s it happening in Ireland:
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…
Re: US Streetlights Are Turning Purple
#24> 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 ha…
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Re: US Streetlights Are Turning Purple
#25> 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 c…
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.
Re: US Streetlights Are Turning Purple
#26> 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 c…
> Get a crew out there and figure it out.
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.
Re: US Streetlights Are Turning Purple
#27> 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 c…
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.
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.
Re: US Streetlights Are Turning Purple
#28“ 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.
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.
If orange was tolerated before, I am curious why orange LEDs aren’t being looked at again for resilience.
Re: US Streetlights Are Turning Purple
#29“ 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.
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.
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.
Re: US Streetlights Are Turning Purple
#30Earlier quoted context omitted.
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.
Sodium lights aren’t even orange in the normal sense of the word. They only emit one wavelength.
I thought it was two - the sodium double emission line.