https://www.cnn.com/2016/06/21/health/led-streetlights-ama/index.html (https://www.cnn.com/2016/06/21/health/led-streetlights-ama/index.html)
http://www.bbc.com/news/magazine-38526254 (http://www.bbc.com/news/magazine-38526254)
After looking up whether amber LEDs were a thing, I came across quite a few sources stating the potential dangers of LEDs. The whiter the light, the more blue wavelengths it has, which can mess with your sleep, which in turn can cause poor health quality. They also make light pollution a lot worse. They might even be bad for visibility.
So, not only do regular LEDs look horrible, (admit it, the LED cobra heads look awful :pan: and so does the white light at night, the amber glow is a lot more pleasant (this was intended to be more lighthearted)) but they're also bad for your health and bad for light pollution, which can affect wildlife and your sleep.
To solve this issue, some cities have been switching to amber LEDs, like the ones pictured below:
(https://media.discordapp.net/attachments/270725488958373888/449705188396105729/unknown.png)
It's a nice compromise between the energy benefits of LEDs and the lighting benefits of high pressure sodium. The visibility benefits, however, of pure white light are lost. One city in Arizona (Flagstaff? It was in another article that I can't remember) has solved this partially by planning to put brighter, more intense color temperature LEDs on major roads, and lower color temperature LEDs on minor and residential roads.
Taking another image from Google, I don't know about you, but this just looks plain unpleasant.
(https://media.discordapp.net/attachments/270725488958373888/449704426333012018/unknown.png)
I really prefer amber. It does not interfere with your ability to go to sleep one bit, and its easier on the eyes
I'll politely disagree. I strongly prefer the white light over the amber.
So it's not really the LEDs that are a health risk, it's the inability to fall asleep while laying on a road underneath a white LED.
Oh, wait, it *can* cause you to lose sleep. Everything in the world is a health risk if it can cause something.
Wake me up when there's better evidence of such.
There's evidence that the blue part of the light may lead to increased risk of cancer. Blue light decreases melatonin, which may disrupt the synchronization of the clocks in cells. This, even without observable affects on sleep, may increase cancer risk. Melatonin itself also acts as an anti-oxidant and may suppress some cancers (including types that blue light seems to increase the risk of).
Quote
"In this study, we focused on the satellite images, because other satellites cannot see the colors," but astronauts aboard the space station can, he added. "And so this is the first study to put an experimental value on the correlation between blue light in the general population with the risk of breast cancer and prostate cancer."
But exposure to other kinds of outdoor artificial light -- such as those that are high in the red and green portions of the visible spectrum -- was not positively associated with the development of either type of cancer, the study states.
"That finding was unexpected but suggests that it is really the blue light that is important for cancer rather than just general brightness of light," said Kristen Knutson, associate professor of neurology at Northwestern University's Feinberg School of Medicine, who was not involved in the new study.
https://www.cnn.com/2018/04/27/health/artificial-blue-light-prostate-breast-cancer-study/index.html (https://www.cnn.com/2018/04/27/health/artificial-blue-light-prostate-breast-cancer-study/index.html)
Quote from: jeffandnicole on May 26, 2018, 10:23:51 AM
So it's not really the LEDs that are a health risk, it's the inability to fall asleep while laying on a road underneath a white LED.
Oh, wait, it *can* cause you to lose sleep. Everything in the world is a health risk if it can cause something.
Wake me up when there's better evidence of such.
I would assume this affects residents who sleep in the rooms facing those illuminated streets.
Not commenting about health risks of LEDs specifically, but headlights and engine noise from passing cars (and god forbids there is a fire station down the street!) can easily be part of sleep problem. Solid curtains can make a big difference, though.
I wonder if bluer lights help drivers stay more alert as compared to amber, leading to less falling asleep while driving.
OTOH, the bluer the light, the slower one's eyes are to dilate back open when entering a darker area. (You young people with young eyes might respond quickly, but some of us old farts struggle to recover from being blinded by those really blue LED headlights.) Maybe not as relevant in city driving with light everywhere, but I prefer the amber lights on the suburban and rural segments of the interstates so that I transition easily to dark rural driving.
Seriously? There's a whole spectrum (literally) between the bluish 4000K+ color temperature of high-output LEDs and the piss orange 2200K of high pressure sodium. Why replicate something that looks like crap instead of going for a happy medium of 2700K (incandescent) or 3000K (halogen) that people are most likely to have in their homes? That doesn't mean you have to swing the pendulum so far the other way. I do agree that the new LEDs are too blue, because while 4000K is actually much less blue than typical daylight (more like 5000 to 6500K), our eyes are more sensitive to blue light when it's darker, so "daylight" color temperature looks much bluer to us if it's not super bright.
Lighting has multiple goals (wayfinding, crime prevention, road safety, aesthetics, comfort, accentuation, etc.), and if you only focus on one then you get very compromised results like these. That top photo makes the neighborhood look absolutely vile, like some sort of dystopian video game simulation. I find it repulsive, and I bet any two people looking at each other in that light or seeing it streaming through their windows would agree. The second image may be a bit bright (easy to fix, though that could just be a factor of camera exposure), but it's a street I wouldn't mind walking down or living on by comparison.
Quote from: jjakucyk on May 26, 2018, 04:12:45 PM
Seriously? There's a whole spectrum (literally) between the bluish 4000K+ color temperature of high-output LEDs and the piss orange 2200K of high pressure sodium. Why replicate something that looks like crap instead of going for a happy medium of 2700K (incandescent) or 3000K (halogen) that people are most likely to have in their homes? That doesn't mean you have to swing the pendulum so far the other way. I do agree that the new LEDs are too blue, because while 4000K is actually much less blue than typical daylight (more like 5000 to 6500K), our eyes are more sensitive to blue light when it's darker, so "daylight" color temperature looks much bluer to us if it's not super bright.
Lighting has multiple goals (wayfinding, crime prevention, road safety, aesthetics, comfort, accentuation, etc.), and if you only focus on one then you get very compromised results like these. That top photo makes the neighborhood look absolutely vile, like some sort of dystopian video game simulation. I find it repulsive, and I bet any two people looking at each other in that light or seeing it streaming through their windows would agree. The second image may be a bit bright (easy to fix, though that could just be a factor of camera exposure), but it's a street I wouldn't mind walking down or living on by comparison.
Nobody should be installing new incandescent lights anymore; they're too inefficient.
Quote from: 1 on May 26, 2018, 04:25:51 PM
Quote from: jjakucyk on May 26, 2018, 04:12:45 PM
Seriously? There's a whole spectrum (literally) between the bluish 4000K+ color temperature of high-output LEDs and the piss orange 2200K of high pressure sodium. Why replicate something that looks like crap instead of going for a happy medium of 2700K (incandescent) or 3000K (halogen) that people are most likely to have in their homes? That doesn't mean you have to swing the pendulum so far the other way. I do agree that the new LEDs are too blue, because while 4000K is actually much less blue than typical daylight (more like 5000 to 6500K), our eyes are more sensitive to blue light when it's darker, so "daylight" color temperature looks much bluer to us if it's not super bright.
Lighting has multiple goals (wayfinding, crime prevention, road safety, aesthetics, comfort, accentuation, etc.), and if you only focus on one then you get very compromised results like these. That top photo makes the neighborhood look absolutely vile, like some sort of dystopian video game simulation. I find it repulsive, and I bet any two people looking at each other in that light or seeing it streaming through their windows would agree. The second image may be a bit bright (easy to fix, though that could just be a factor of camera exposure), but it's a street I wouldn't mind walking down or living on by comparison.
Nobody should be installing new incandescent lights anymore; they're too inefficient.
That's not what I was saying at all. Use LEDs at 2700-3000K instead of 2200K.
This is a pretty good rundown of the too-blue vs too-orange situation.
http://www.chicagomag.com/city-life/April-2017/Its-Really-Hard-to-Figure-Out-What-Color-a-Citys-Streetlights-Should-Be/
"Bright White" typically means 3500K, aka "Neutral White". The most common LED streetlights are "Cool White" 4000K or "Daylight White" 5000K.
Besides greater efficiency, it would seem to be not being able to go to sleep on the street is a feature rather than a bug and the cool white / daylight white causes red taillights and traffic signals to stand out more.
Notable that Soraa makes a household LED bulb that emits absolutely zero blue light, the "Healthy". They suggest it's use in bedrooms. Related is their "Radiant" which has extremely high CRI. These both use violet rather than blue emitters, and have red, green, (and for the "radiant, blue) phosphors instead of the typical blue emitters with yellow phosphors.
Quote from: Mdcastle on May 26, 2018, 06:12:15 PM\
Notable that Soraa makes a household LED bulb that emits absolutely zero blue light, the "Healthy". They suggest it's use in bedrooms. Related is their "Radiant" which has extremely high CRI. These both use violet rather than blue emitters, and have red, green, (and for the "radiant, blue) phosphors instead of the typical blue emitters with yellow phosphors.
The way that "healthy" spectrum looks, seems like they use 405 nm LED, and I would think twice about touching that with a 10 foot pole for hours a day exposure.
Also, I thought blue and yellow is a thing of a distant past..
Quote from: wxfree on May 26, 2018, 10:50:27 AM
There's evidence that the blue part of the light may lead to increased risk of cancer. Blue light [...]
Says that while using device of which around 1/3 of light emoted is blue....
I always thought of the bright white color as being associated with nicer, richer areas.The standard streetlights in the poorer neighborhoods were the yellow sodium cobra heads, and as the communities got nicer, the fixtures got nicer, with nicer bulbs as well, such as mercury vapor or metal halide, and the reasoning was metal halide had a higher operational and maintenance cost then sodium vapor. If you wanted to be able to differentiate people though, you needed it. The goal on highways and other areas, though, was simply to let you know something was there, so sodium vapor was a cheaper way to do that.
LEDs are finally letting the poorer areas experience what the rich areas have for some time: the ability to actually make our an actual person at night, the ability to take clear pictures, etc. LEDs are also directional by their very nature, so if any effort is made at all, LEDs eliminate the light pollution that sodium vapor is so famous for, with the orange hazy skies.
Liking the yellow sodium vapor light is simply liking what you grew up with. You can't tell a single house color in your first pic, while the second one, you can see the house colors/materials, car color, etc.
Personally, I rather interrupt the sleep pattern of drivers, who knows, it may prevent people from falling asleep behind the wheel. As for light spillover into neighboring homes, someone didn't do their homework in the fixture placement, orientation, programming of the fixture, or some combination of those. If it's still spilling into residences and hotels, buy some fucking opaque curtains and be done with it. Just say 'no' to more yellow/peach/orange fixtures; they interrupt my healthy digestive cycle and cause food to come out the wrong end.
When they started phasing in bright white LED streetlights around my area, I really liked them, but I was not yet aware of the potential problems they could cause (until now).
Even if we can solve the problems of people falling asleep (such as with curtains), we still face the other problem that was mentioned in the OP - light pollution, so it may still be something to be wary about.
Here is a direct quote from this article: https://www.globeatnight.org/light-pollution.php
Quote
Effects of Light Pollution
In disrupting ecosystems, light pollution poses a serious threat in particular to nocturnal wildlife, having negative impacts on plant and animal physiology. It can confuse the migratory patterns of animals, alter competitive interactions of animals, change predator-prey relations, and cause physiological harm. The rhythm of life is orchestrated by the natural diurnal patterns of light and dark; so disruption to these patterns impacts the ecological dynamics.
With respect to adverse health effects, many species, especially humans, are dependent on natural body cycles called circadian rhythms and the production of melatonin, which are regulated by light and dark (e.g., day and night). If humans are exposed to light while sleeping, melatonin production can be suppressed. This can lead to sleep disorders and other health problems such as increased headaches, worker fatigue, medically defined stress, some forms of obesity due to lack of sleep and increased anxiety. And ties are being found to a couple of types of cancer. There are also effects of glare on aging eyes. (See text below.) Health effects are not only due to over-illumination or excessive exposure of light over time, but also improper spectral composition of light (e.g., certain colors of light).
So, to some extent, curtains or no curtains, according to everything I have now read and heard, it sounds like these new lights could potentially cause at least
some kind of adverse effects to people (and wildlife), so perhaps it may be best to replace them with amber LED lights, which were mentioned in the OP. I did like the way the white LED lights looked, but I also like the way the amber LED lights look as well, and if the white LED lights have more potential to cause problems, then perhaps it is best in the end that we not use them.
Quote from: adventurernumber1 on May 27, 2018, 01:13:07 AM
When they started phasing in bright white LED streetlights around my area, I really liked them, but I was not yet aware of the potential problems they could cause (until now).
Even if we can solve the problems of people falling asleep (such as with curtains), we still face the other problem that was mentioned in the OP - light pollution, so it may still be something to be wary about.
Here is a direct quote from this article: https://www.globeatnight.org/light-pollution.php
Quote
Effects of Light Pollution
In disrupting ecosystems, light pollution poses a serious threat in particular to nocturnal wildlife, having negative impacts on plant and animal physiology. It can confuse the migratory patterns of animals, alter competitive interactions of animals, change predator-prey relations, and cause physiological harm. The rhythm of life is orchestrated by the natural diurnal patterns of light and dark; so disruption to these patterns impacts the ecological dynamics.
With respect to adverse health effects, many species, especially humans, are dependent on natural body cycles called circadian rhythms and the production of melatonin, which are regulated by light and dark (e.g., day and night). If humans are exposed to light while sleeping, melatonin production can be suppressed. This can lead to sleep disorders and other health problems such as increased headaches, worker fatigue, medically defined stress, some forms of obesity due to lack of sleep and increased anxiety. And ties are being found to a couple of types of cancer. There are also effects of glare on aging eyes. (See text below.) Health effects are not only due to over-illumination or excessive exposure of light over time, but also improper spectral composition of light (e.g., certain colors of light).
So, to some extent, curtains or no curtains, according to everything I have now read and heard, it sounds like these new lights could potentially cause at least some kind of adverse effects to people (and wildlife), so perhaps it may be best to replace them with amber LED lights, which were mentioned in the OP. I did like the way the white LED lights looked, but I also like the way the amber LED lights look as well, and if the white LED lights have more potential to cause problems, then perhaps it is best in the end that we not use them.
LEDs reduce light pollution, they're directional by nature, and never shoot light straight up into the sky, sodium vapor lights generally shoot light everywhere, including upwards and cause real light pollution.
The amber LEDs cause everything to look monochrome, making them much less useful.
I still wonder if they need to be shielded.
The "warmer" LEDs are a reasonable compromise to the harsh bluish color in areas where people have to see them a lot. On an expressway it is one thing but on a residential street or even a street downtown with lots of pedestrian activity all night, it's another.
It is worth noting that one downside of sodium lighting that has been noted is that "everybody looks orange" (Tribune article mentioning studies of this (http://articles.chicagotribune.com/2011-08-06/news/chi-chicago-starts-replacing-lights-that-have-shrouded-city-in-orange-glow-20110806_1_sodium-vapor-new-lights-orange-glow)) so people couldn't give accurate descriptions of suspects, an odd backfiring of tons of lighting being a crime-fighting measure pushed by Mayor Daley when mercury went out and sodium came in.
Even in the house, different LEDs make sense for different places. The bluish ones are OK in the kitchen, but not the living room somehow. And definitely not the bedroom. I've stayed in a couple hotels where they had all LED bulbs and use the bluish ones everywhere, even on the nightstand, and they are noticeably disagreeable.
Quote from: adventurernumber1 on May 27, 2018, 01:13:07 AM
When they started phasing in bright white LED streetlights around my area, I really liked them, but I was not yet aware of the potential problems they could cause (until now).
How remember similar comments about...cell phones? And cell phone towers?
A common complaint in areas where people didn't want a cell phone tower was the unknown cancer-causing effects of such. Even 20, 25 years later, people still tried using these complaints as reasons not to have towers, even though there was no concrete evidence of such. Some studies said that the phone itself was where the cause for concern lies...although people suddenly didn't seem terribly concerned about that risk, even though it's literally touching the person's head.
So when we're talking about 'potential' problems of LEDs...they seem to fall more into the pattern of people just don't like it more so than there's actually an issue to worry about.
There are numerous vendors selling "warm white" LED's that mimic incandescent illumination; the problem is that the mcd (millicandle) ratings are about 30-35% lower than blue-based "flashlight" white bulbs, so substantially more would have to be grouped together to produce the same lumen output. They also used to be considerably more expensive than blue/white, but there is little difference presently. Diffused white, while still retaining a slightly bluish tint, only loses about 10% of its lumen value compared with clear/blue white; that particular variety is starting to show up as internal illumination in electronics (audio, test equipment, what's left of desktop computers) simply because it's a lot easier on the eyes than clear white while retaining most of the brightness levels. Wouldn't be surprised to see the diffused-white variant showing up in streetlights in the not too distant future.
In the past several months, our older incandecent anti-light pollution (we're close to an airport) street lights were replaced with bright white LEDs.
While I think they are better at directing light where it's needed than the prior fixtures (judging by what I see when landing at night), I have three objections with them:
First, in certain positions with respect to the fixture, the glare is much worse than the prior lights.
Second, when I need to walk down to the street at night (late night check of the mail, rolling trash barrels to/from the street), I can no longer make use of visual cues to tell when a car is about to crest a hill to my east, or come around a curve to my west -- the light color is no longer sufficiently different from headlights.
Third, they're too d-mn bright. While that does help with visibility, you don't have to go too far to find unlit roadways, where having less-ruined night vision would be handy.
I think in the future we will see lighting implemented better, like glowing in the dark lane strips and more diffused lighting "from within" that may allow for health benefits of a dark sky....
that all of human history enjoyed for thousands of years until the electric light made its debut.
The lighting outside my house is low pressure sodium which is the really deep yellow/orange stuff. I know it's living on borrowed time and I know what its replacement will be. However most LED lighting here is slightly off white so isn't quite as cold in temperature as mercury vapour. It remains to be seen if LED will intrude into the house when it arrives.
I remember seeing the then-new HPS lights go up in Chicago at a young age. Due to them being known for their installation in high-crime areas of large cities, I always made sure to stay as far away from them as possible, but inevitably, they were impossible to avoid on my way to Cubs games and such. Although I like seeing LED lights, the luminaires themselves are ass-ugly. It makes me wonder why they couldn't have saved the old cobraheads and simply retrofit those for LED use, like they did MV to HPS.
I love that the city of Des Moines has been replacing their old lamps with the newer white LEDs. I always hated the orange hue the old lamps covered everything with at night.
I've seen cobrahead and shoebox retrofits, generally you install a panel of LEDs just above the glass. But with replacing the ballast and not using the existing optics all that's salvageable is the fixture shell. And most HPS fixtures have been out in the elements for decades. Best just to pop a new fixture on.
Different light wavelengths can distort visual perception. White light is completely neutral.
Why would artificial blue light be harmful if the amount you get from the sun is much more than any streetlight?
For the same reason experts recommend against looking at computer screens, TVs, cell phones, and other devices shortly before going to bed.
Quote from: 1 on May 30, 2018, 09:34:21 AM
Why would artificial blue light be harmful if the amount you get from the sun is much more than any streetlight?
This is about blue light and sleep cycle. Theory is that blue light affects level of melathonin, which is associated with sleep cycle.
If you will, sun will also prevent you from falling asleep - but sunlight usually means it is not time to sleep anyway. Hence it is not a problem until you work night shift and need good curtains.
More here: https://www.scientificamerican.com/article/q-a-why-is-blue-light-before-bedtime-bad-for-sleep/
On a different note, UV in the sunlignt is potentially harmful in terms of skin cancer probability - and someone upstream recommended UV emitting lamps as solution for blue-induced sleep problems. What do you prefer, sleep problems or cancer?
According to various researchers, scientists, and fun police, pretty much everything causes cancer/disease/negative consequences. So I'm just going to ignore that for now.
Putting that aside, I still prefer the old amber lights over the bright LEDs. They're great in certain places, but at other times they're just excessively harsh in certain locations. It's taken me a while to get used to driving the Jane Adams out west from Chicago since the rebuild. I will agree visability is great, but I still actually enjoy driving the section of US-20 around Rockford more. There's just something slightly more calming about it for me. Maybe it's just nostalgia.
Someone used the phrase happy medium earlier, and I think that describes what's best. Something whiter than the old, but not excessively harsh.
I’d favor a compromise of putting the brighter white LEDs on freeways and arterials and amber LEDs on neighborhood streets, assuming the cost is about the same. The harsh light color could keep drivers awake, and the fact that white LEDs contain enough blue to mess with the sleep cycle might be useful in protecting against drowsy driving on major roads. On minor streets and in neighborhoods, the amber lights give a warmer color that’s easier on the eyes, even if they make everything look orange. Most people aren’t going to want a lot of efficient harsh blue LED light shining into their homes every night.
Some discussions that I read on this over the past couple of years also alluded to 4000-5000K LEDs messing with the sleep cycles of wildlife (ie, birds singing at the wrong times, etc).
Mike
In the Twin Cities that's kind of what's happening: Mn/DOT and the cities are using the 4000K Cool White LEDs on the freeways and major streets. After using cool white in Bloomington and a few other south metro suburbs Xcel switched to warm white for the rest of their conversion project. Unfortunately the warm white of the GE Evolve fixture's they're using isn't very pleasing compared to the warm white of some other makers. To me "warm white" streetlights seem to be about halfway between 2700K soft / warm white and 3500K bright / neutral white, and the Evolves have an ugly pink cast.
I convinced my sister to use LEDs in her bedroom because she rarely remembers to turn them off. After trying abut a half dozen different lamps she settled on 3500K bright white. Interestingly enough there was a study done with a company that makes really high end "tunable" lamps that have both 2700K and 5000K primary emitters, as well as secondary RGB emitters. They found most people liked really blue light in the kitchen and about 3500K with a slight reddish cast in other areas.
Quote from: JoePCool14 on May 30, 2018, 11:07:03 PM
According to various researchers, scientists, and fun police, pretty much everything causes cancer/disease/negative consequences. So I'm just going to ignore that for now.
Putting that aside, I still prefer the old amber lights over the bright LEDs. They're great in certain places, but at other times they're just excessively harsh in certain locations. It's taken me a while to get used to driving the Jane Adams out west from Chicago since the rebuild. I will agree visability is great, but I still actually enjoy driving the section of US-20 around Rockford more. There's just something slightly more calming about it for me. Maybe it's just nostalgia.
I hate to play the age card, but street lights weren't always amber/orange/peach.
Yes, A lot of us still remember when cities were blue.
My first response to the blue light thing was to shake my head, since we've always had a lot of bluish lights around us. But when you look at the actual spectrum emitted as opposed to how we perceive it, mercury vapor and fluorescent tend to have a a spike centered around violet, rather than blue. That's the idea behind the Soraa LED, to emit a spectrum more like fluorescent and mercury vapor and less like traditional white LED.
Yeah, I prefer the bright white LEDs. I believe the light pollution problem is being handled by better directing the light downwards rather than changing the color of the light. The light pollution issue from LEDs came to light(pun intended) awhile ago, but again, I believe they have found ways of dramatically reducing that effect by better directing the light downwards by using better covers and shields.
As for the cancer issue, give me a break. What doesn't cause cancer anymore?
Quote from: DaBigE on May 31, 2018, 12:56:41 PM
Quote from: JoePCool14 on May 30, 2018, 11:07:03 PM
According to various researchers, scientists, and fun police, pretty much everything causes cancer/disease/negative consequences. So I'm just going to ignore that for now.
Putting that aside, I still prefer the old amber lights over the bright LEDs. They're great in certain places, but at other times they're just excessively harsh in certain locations. It's taken me a while to get used to driving the Jane Adams out west from Chicago since the rebuild. I will agree visability is great, but I still actually enjoy driving the section of US-20 around Rockford more. There's just something slightly more calming about it for me. Maybe it's just nostalgia.
I hate to play the age card, but street lights weren't always amber/orange/peach.
Interesting, I did not know that.
My city just went through the process of switching, including a public process. We opted for a 3000K lamp, and they look great. They have just a cone of light pointing down, and you can see quite well. The color isn't likely going to cause much of a problem regardless, as there is practically no spillage anymore. My bedroom used to have the amber hue of the streetlight on the adjacent corner, but now, nothing.
Right outside my bedroom there is a bright white LED street light. I would prefer a amber colored LED light, but it doesn't really bother my sleep that much. It doesn't have a huge effect this time of year anyways because sunset is so late in the evening.
Quote from: UCFKnights on May 27, 2018, 07:15:03 AM
LEDs reduce light pollution, they're directional by nature, and never shoot light straight up into the sky, sodium vapor lights generally shoot light everywhere, including upwards and cause real light pollution.
Nnnn... LEDs reduce
ambient light pollution. That does not mean they don't have problems with
local light pollution. After all, while it is a narrower beam, it is a brighter beam, which makes it worse if it happens to be pointed at you.
Meanwhile the directional nature of LEDs can cause problems of its own. Plenty of jurisdictions which previously had their streets decently thoroughly lit have switched to LEDs and suddenly started having dark spots where they did not previously exist. One block near us now has basically no light on the sidewalk at night since the lights were changed to LEDs. The previous HPS fixtures lit up the sidewalk almost as well as the street.
On a similar note, my in-laws now complain that ever since the lights on their street were changed to LED, their front porch is now dark whereas the old streetlights lit it up at night. It's not the city's responsibility to light up their front porch, they were just getting it as a free service by accident when they were never entitled to it - but, you change anything, and people will complain. So it goes.
As for the prevalance of 5000K LEDs... it is worth noting that this is a natural consequence of how the technology works. The diodes themselves in LED lamps actually give off blue (like, legit pure blue) light, because diodes that emit at this wavelength are the cheapest to manufacture. The light is then made the desired color by placing a phosphor cap over the diode.
Since the light starts out blue, using phosphor to make it 5000K gets you a slightly less expensive to manufacture and slightly more efficient (in terms of lumens per watt) fixture than using more phosphor to get the color temperature down further.
Quote from: Duke87 on June 13, 2018, 12:01:09 AM
Meanwhile the directional nature of LEDs can cause problems of its own. Plenty of jurisdictions which previously had their streets decently thoroughly lit have switched to LEDs and suddenly started having dark spots where they did not previously exist. One block near us now has basically no light on the sidewalk at night since the lights were changed to LEDs. The previous HPS fixtures lit up the sidewalk almost as well as the street.
Once again, it sounds like someone didn't do their homework when looking to retrofit. Photometric analyses don't require a lot of effort to produce, since the major manufacturers produce fixture files that can be directly imported into software like AGi32. You can tell nearly exactly where and what intensity light will be produced, given your pole spacing and mounting height. Changing a streetlight fixture is not as straight-forward as converting your table lamp bulb, but too many try to make it seem like it is. I've seen some really nice conversions which virtually eliminated any hot/dark spots encountered with HPS fixtures, and ending up with very uniform lighting with LEDs without having to move a single pole.
Interesting video weighing the pros and cons of LED/sodium.
This guy's channel also has a lot of other interesting videos.
https://www.youtube.com/watch?v=U1dMlVwUsrA
Another video.
I used to work for the United States Postal Service for several Decembers and one six month summer vacation replacement period. I had to work under orange sodium vapor lights, and I hated them. Twice there were power outages at the air mail center where I worked, and the temporary lights, or working out in the dock, made things so much more pleasant and color balanced.
Quote from: index on June 19, 2018, 03:29:53 PM
Interesting video weighing the pros and cons of LED/sodium.
This guy's channel also has a lot of other interesting videos.
Another video.
Beat me to it. He covers all the bases really well and came to basically the same conclusion I did, that LEDs are still the way to go, but at a roughly 3000K color temperature.
In my new apartment I just swapped out an assortment of old incandescent/CFI/missing bulbs in the common areas for Walmart's Daylight (nominally 5000k, but reported to be closer to ~4500k) bulbs. In my bedroom, I'm testing the same bulbs for the ceiling light, accented with a 2700k bulb in a lamp for nighttime.
I personally like the more neutral white color from the 5000k bulbs after trying them; for daytime and early-evening use, 2700k bulbs have more of a de-energizing effect than I want after comparing both.
For public areas, I lean towards 4-5000k bulbs for commercial areas and arterial streets, and 25-3500k bulbs for residential areas.
Here's my thoughts on lighting applications.
-Sodium vapor for neighborhood streets/light (don't know the proper term) commercial districts (example? (https://www.google.com/maps/@39.6142154,-77.6909293,3a,75y,345.34h,86.28t/data=!3m6!1e1!3m4!1suH7Zp1zMyYCkgTEYIKm-xw!2e0!7i13312!8i6656))
-LEDs for freeways and major streets inside urban areas
-No lighting/minimal sodium vapor lighting in rural areas
For LEDs...not exactly a big fan of them. I have a computer in the same room as my bedroom, and whenever that's on, there's blinding blue light shining onto the bed, so it's hard to sleep without blocking it. To give an example of how bright, the small LEDs inside a wireless router still keep me up at night (ironically, I block the light using a Sandman comic book). I'm also accustomed to sodium vapor light, which is easy on the eyes and lights up the room, so I'm not complaining.
I miss old fashioned light bulbs...and when streetlights were on a timer so they all came on, fully lit, at the same time.
Quote from: noelbotevera on August 12, 2018, 07:21:38 PM
For LEDs...not exactly a big fan of them. I have a computer in the same room as my bedroom, and whenever that's on, there's blinding blue light shining onto the bed, so it's hard to sleep without blocking it. To give an example of how bright, the small LEDs inside a wireless router still keep me up at night (ironically, I block the light using a Sandman comic book). I'm also accustomed to sodium vapor light, which is easy on the eyes and lights up the room, so I'm not complaining.
Why not just shut the computer off? I'm sure there's probably a long update or two, but those shouldn't be happening every night.
Quote from: DaBigE on August 13, 2018, 08:58:33 AM
Quote from: noelbotevera on August 12, 2018, 07:21:38 PM
For LEDs...not exactly a big fan of them. I have a computer in the same room as my bedroom, and whenever that's on, there's blinding blue light shining onto the bed, so it's hard to sleep without blocking it. To give an example of how bright, the small LEDs inside a wireless router still keep me up at night (ironically, I block the light using a Sandman comic book). I'm also accustomed to sodium vapor light, which is easy on the eyes and lights up the room, so I'm not complaining.
Why not just shut the computer off? I'm sure there's probably a long update or two, but those shouldn't be happening every night.
My dad writes articles and watches movies at night, so I can't turn off the computer whenever he's home. Luckily it's only on the weekends, otherwise that computer stays off.