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  #101  
Old Posted May 21, 2019, 8:35 PM
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aaron38 aaron38 is offline
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Color temperature is very important, as those images show. Dropping from 3000K to 2700K is a big difference, bigger than you can tell from a computer monitor. They should have picked 2700K.
Personally I won't miss the orange that much, I never liked the orange skyglow on cloudy days, never liked that after a snowstorm everything was universally orange.
But much of that had to do with the lack of full cutoff lighting fixtures. I do hope skyglow is much less, and more stars are visible at night. People in cities deserve to see the stars.

As for safety, the issue is poor lighting design. Overly bright lighting is actually worse for personal safety as it disables people's night vision, creates very dark shadows for a criminal to hide in, see everything and not be seen.

Vision is logarithmic with respect to brightness. Street light levels could easily be cut in half (brightness, not number of lamps) and people would be able to see just fine, and be able to easily see into shadows. Uniform dim lighting is better for night safety than isolated islands of glare.
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  #102  
Old Posted May 21, 2019, 9:18 PM
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Originally Posted by Steely Dan View Post
for like the 3rd time now, chicago's new LED streetlights are 3000K.

they are still very noticeably whiter than the old 2200K HP sodium lamps they are replacing.

my neighborhood is no longer orange at night, and i miss that.
Yeah, sorry, i figured somewhere in the thread the new color temp might be mentioned, but I couldn’t bear to read 5 pages.

3000k is definitely noticeably whiter than 2200k. Not sure if they make 2200k LED street lamps, but they do make 2700k LED streetlamps.
I hear you on the orange nighttime glow in the city. There’s something much more comforting about the diffuse haze rather than the directed white beam
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  #103  
Old Posted May 21, 2019, 9:27 PM
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in addition to the temperature change, i think the thing that makes the switch even more noticeable to my eye is that the new LED lamps must have a CRI that is an order of magnitude higher than the old sodium lamps.

with the new LED streetlights i can actually make out the true color of objects now, blue looks like blue, red looks like red, green looks like green, etc.

with the old sodium lamps, everything was just washed out in a sea of unrelenting orange. i liked that. it felt magical and moody. but alas, no more.

now, night time is a lot more like day time, there's no more weird transformation into "orange world" at twilight.
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  #104  
Old Posted May 21, 2019, 10:54 PM
Encolpius Encolpius is offline
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Quote:
Originally Posted by aaron38 View Post
Vision is logarithmic with respect to brightness. Street light levels could easily be cut in half (brightness, not number of lamps) and people would be able to see just fine, and be able to easily see into shadows. Uniform dim lighting is better for night safety than isolated islands of glare.
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Originally Posted by Steely Dan View Post
with the old sodium lamps, everything was just washed out in a sea of unrelenting orange. i liked that. it felt magical and moody. but alas, no more.

now, night time is a lot more like day time, there's no more weird transformation into "orange world" at twilight.
These two points pretty much sum up my feelings on this issue. Particularly the second one. Humans have rod cells in our retinas that perceive the world in monochrome when lighting is dim, which means that for eons we've experienced the nighttime world as if it spoke a different, more primitive tectonic language than daytime, one of volumes, voids and silhouettes. This means that city streets bathed in a dim orange glow seem simpler, more solid, almost like negative space onto which we can project the color of our emotions or the forms of our imagination.

On the other hand, rods are better than cones at picking up movement. You'll more readily perceive a rat or cockroach scurrying across the sidewalk at night than during the day. Or something stirring in the shadows. In places far more dimly lit than most American cities, we don't lose the ability to see. Instead, our inanimate surroundings demand less of our attention.
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  #105  
Old Posted May 21, 2019, 11:07 PM
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Also, don't think anybody's mentioned this yet: LEDs flicker like computer screens. Yuck.
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  #106  
Old Posted May 22, 2019, 12:47 PM
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Originally Posted by Steely Dan View Post
in addition to the temperature change, i think the thing that makes the switch even more noticeable to my eye is that the new LED lamps must have a CRI that is an order of magnitude higher than the old sodium lamps.

with the new LED streetlights i can actually make out the true color of objects now, blue looks like blue, red looks like red, green looks like green, etc.

with the old sodium lamps, everything was just washed out in a sea of unrelenting orange. i liked that. it felt magical and moody. but alas, no more.

now, night time is a lot more like day time, there's no more weird transformation into "orange world" at twilight.
Yeah, that makes sense. LEDs are a far, far superior lighting solution to incandescent, hps, metal halide, fluorescent, etc. in so many ways, but I agree with you and I do lament the loss of the nighttime atmosphere in the city created by sodium lamps. I'm hoping LEDs can be fine-tuned to match that effect.

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Also, don't think anybody's mentioned this yet: LEDs flicker like computer screens. Yuck.
Only if they're cheap shit LEDs.

Or if they are on non-LED dimmers.
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  #107  
Old Posted May 22, 2019, 5:56 PM
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I paid attention to the streetlights while walking my dog last night, and realized that in my neighborhood in Los Angeles, the residential portions are lit with the orange lights, while the commercial strips are lit with the white LEDs. I don't really mind or prefer either one, but the orange lights definitely create a darker street scene. I actually kind of like this hybrid approach, and I think the brighter white lights make sense in commercial areas, as people can better see the businesses as they walk/bike/drive by. I can't recall if this situation is present in other neighborhoods in LA, but I don't get the sense that my neighborhood is transitioning to the white lights. I think the dual lighting system has been in place for several years.
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  #108  
Old Posted May 22, 2019, 7:29 PM
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Quote:
Originally Posted by edale View Post
I paid attention to the streetlights while walking my dog last night, and realized that in my neighborhood in Los Angeles, the residential portions are lit with the orange lights, while the commercial strips are lit with the white LEDs. I don't really mind or prefer either one, but the orange lights definitely create a darker street scene. I actually kind of like this hybrid approach, and I think the brighter white lights make sense in commercial areas, as people can better see the businesses as they walk/bike/drive by. I can't recall if this situation is present in other neighborhoods in LA, but I don't get the sense that my neighborhood is transitioning to the white lights. I think the dual lighting system has been in place for several years.
Yeah there are still some neighborhoods in Los Angeles that have the old high-pressure sodium vapor lamps. Are the ones in your neighborhood on wooden poles? I live in South Pasadena and when I drive into Garvanza/Highland Park, I see some of the sodium vapor lamps on the wooden poles, and when I see the concrete poles they are the LED lamps.

Going back to the topic of the thread, I don't doubt that when incandescent street lamps started disappearing, that people didn't like the greenish mercury vapor lamps or the orangey sodium lights. As recently as the 90s (maybe even into the two-thousand aughts), there were some wealthy neighborhoods of LA, like Holmby Hills and Hancock Park, and even some middle-class neigbhorhoods, that still had incandescent streetlights. They were in the acorn lamp streetlights. And by acorn lamp, I mean this style; I guess it's called an acorn globe:



Someone else posted what they called an acorn lamp but to me that's more gumball or teardrop (probably more like gumball).

Anyway, the incandescents acorn globes gave off a really nice, old-fashioned looking light. Very noirish.
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  #109  
Old Posted May 22, 2019, 7:46 PM
edale edale is online now
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Quote:
Originally Posted by sopas ej View Post
Yeah there are still some neighborhoods in Los Angeles that have the old high-pressure sodium vapor lamps. Are the ones in your neighborhood on wooden poles? I live in South Pasadena and when I drive into Garvanza/Highland Park, I see some of the sodium vapor lamps on the wooden poles, and when I see the concrete poles they are the LED lamps.
Yes, the orange lights are on wooden poles. This is what they look like:
https://www.google.com/maps/@34.1078...7i16384!8i8192

The white LEDs are on metal poles that look like these: https://www.google.com/maps/@34.1077...7i16384!8i8192
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