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Comment by nchammas | Hacker News Reader

My town recently replaced the dull, orange-ish street lights in my neighborhood with very bright, white LEDs.

The street is now very well-lit, but I share the author's concerns and experience with this kind of light creating an environment that's not conducive to sleep, or to unwinding in general. When I look at the new street lights I feel like they were taken out of a hospital operating room.

Another thing I noticed when the new lights first went in was that the birds started chirping at all hours of the night. I don't know if they were always doing that and I only noticed after the new street lights were installed, but it makes sense that the light would have a similar impact on animals as it does on humans.

I wonder if anyone else noticed this when the lights in their neighborhood were upgraded to these harsh, white LEDs.

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One of the streets I drive on regularly is the dividing line between two towns, and it actually has the new LED bulbs on one side and the older bulbs on the other. Even without the one malfunctioning LED assembly that's strobing, the difference is pretty jarring and rather disturbing. I'd much rather have the older bulbs back, or at least something closer to them in appearance.

I'm not the only one to notice the difference either - I generally have my phone mounted to my driver's-side vent and on with a map, and when I'm driving on the "old bulb" side of the street with the new bulbs shining from behind on the phone, it's much brighter - presumably its light sensor is perceiving the LEDs as being much closer to daylight.

There are companies making non flat non white LED lamps these days. They try to emulate the feel and color of filament bulbs but with LED films for power savings. I don't know if they improve things though.

They don’t necessarily have the same spectrum. Not an expert, but my conclusion from the little I looked into this is that lighting is hard. And decision makers don’t seem to consider externalities.

The Sodium Lamps normally used in Street Lighting have a very very narrow colorband (their color index is basically 0, if you look at something under sodium light, it's colorless other than the sodium yellow).

LEDs can be more easily adjusted and can have a wider color band plus you can use multiple modules and change color as needed (blue light in early evening when rush traffic is on and then going into narrowband sodium yellow for the night). It's a question of power delivery and PCB complexity that limits what you can do (controlling a high powered 50W LED isn't trivial)

Amber lights are conducive to sleep since blue wavelength light messes with circadian rhythms so they might be useful on stretches of roadway that feature long-haul driving and late-night traffic like larger thorough fares but I think they have a very deleterious effect on animals and plants.

One of the things I love about the suburban neighborhood I live in is how dark it is at night (relatively speaking, not like being in a true night-time darkness in the wilderness).

I live in a neighborhood where many people leave 5-6000K security lights on all night. It boggles my mind. Any possible health effects aside, I just find non-natural light in that spectrum to be really unpleasant to look at. The temperature of the security and street lights really kills an otherwise pleasant neighborhood vibe at night.

It literally costs pennies to fix by using a film to get amber light.

Is the circuitry to change LED colors significantly more expensive? That would future proof any light temperature issues.

Yes.

There's an interesting Wired article, about how teams at Philips struggled to come up with the optimum filter. IIRC, at some point they were using some type of gel to 'tint' the LED light to resemble an incandescent bulb.

Of course, nearly all of this has probably flown out the window, because the bulbs are so cheap now. (The Wired article was from over a decade ago.)

That was the article about the Switch bulbs if I remember correctly. I think the company went out of business. I have a couple of them and they work and look good, but are really heavy and I can't use them in certain applications that were only ever meant to hold up really light incandescents.

It's not circuitry, it's the phosphors used to convert the light from blue to a mix of colors resulting in some form of white.

You can't change blue light to another color with a filter. The amber light has to be in the spectrum emitted by the lights to begin with. The filter just isolates it.

A lot of "white" LEDs have a layer that absorbs some blue light and reemits it at a longer wavelength, with the mix looking white:

http://www.photonstartechnology.com/learn/how_leds_produce_w...

It's not a filter of course.

That's overly simplistic - you can use phosphors (and similar chemicals) to change the color of the light. The phosphors absorb light and emit light of different colors. Many daylight bulbs do this.

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