Author Topic: Sign of the times  (Read 5966 times)

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Offline David Hess

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Re: Sign of the times
« Reply #25 on: May 15, 2021, 06:36:39 am »
One of my earlier memories is lying on the back seat of an Austin A30, feeling horribly travel sick, watching the orange low pressure Sodium lamps drift by.  >:D

I have similar memories and thinking about it now, in order of time they went from largely low pressure sodium, to high pressure sodium, to mercury.

It's certainly going to depend on where you are. Here in the USA mercury vapor absolutely dominated street lighting from about the late 1950s up into the early 1980s. Some areas used clear lamps and others used phosphor coated color corrected lamps, some seemed to use whatever they had on hand at the time. LPS (SOX) that was extremely common in the UK and Europe never really caught on here, there were pockets of them in a few specific areas, particularly in the vicinity of observatories but I've never seen one on a public road up here in the Northwest.

I think it varied a lot between urban, suburban, and rural areas.  LPS was common in rural California where I was born but I never saw them in any large suburban or urban areas.  The small towns in the 1970s still had a lot of them.
 

Offline james_s

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Re: Sign of the times
« Reply #26 on: May 15, 2021, 06:40:51 am »
I think it varied a lot between urban, suburban, and rural areas.  LPS was common in rural California where I was born but I never saw them in any large suburban or urban areas.  The small towns in the 1970s still had a lot of them.

I think it was a California thing. I could swear I saw a few LPS remaining in San Diego I think it was as recently as about 10 years ago. Seems like I heard they were common in Arizona too, or maybe it was New Mexico, I don't even recall now. Up here in my corner I never saw them on public roads anywhere, ever. Rural and urban areas alike went from mercury vapor to HPS and over the past 10 years have been shifting to LED.
 

Offline Ed.Kloonk

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Re: Sign of the times
« Reply #27 on: May 15, 2021, 08:56:35 am »


On another trip to the UK, in 1974" I parked my pink Ford Cortina hire car in a smallish car park, & went to visit some people.
On my return, after dark, I couldn't find a pink Cortina, but there was a yellow one!

Not really that much of a hassle, as the key ring had the Reg number on it, but it had me going for a while.

Might have been pink elephants that were involved?
iratus parum formica
 

Offline richard.cs

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Re: Sign of the times
« Reply #28 on: May 15, 2021, 10:58:53 am »
Yeah that's a massive problem in London as a driver. While I certainly respect cyclists (as a former cyclist) it really annoys the hell out of my when someone comes flying at me on the opposite side of the road with a frigging strobe light going on. I can see you fine if it doesn't flash.  >:(

The slow flashing ones are quite dangerous as the only light (and not generally lawful in the UK*). I remember pulling out of a junction having looked right-left-right and nearly hit a cyclist coming from the right whose light was off both times I looked in his direction. It must have been around 1-2 Hz. When I cycle I never use the flashing modes for this reason.

Coming back to streetlighting. Around here (Southampton UK) it was mostly LPS, with occasional HPS on major roads until maybe 5 years ago. Now residential areas are mostly fluorescent (!?) and dim or turn off from 1 am, most of the major roads are LED with some HPS left at big junctions.

Modern regulations requiring full-cutoff luminaires that do not emit any light above 90 degrees also create a problem of needing more of them to create even illumination and even then you end up with bright pools under the source with dark spaces between.

The problem is retrofitting full-cut-off without changing anything else like pole heights or spacings. It's cheaper but you get this effect.

I can remember sections of the M25 having LPS on catenaries up the central reservation, like this http://imagizer.imageshack.com/a/img922/9831/kq2AUC.jpg I seem to remember the light was fairly even, but it's all gone now in favour of conventional poles. Perhaps maintenance is just easier/cheaper. Not all UK motorways have lighting, mostly the larger, busier ones and around junctions.


*You are allowed to use a light that flashes if it is CE marked and has no other modes. From memory though this is to meet the requirement to have lights, once you have a light that meets this you may be able to add additional lights of any type, not sure.
 

Offline Zero999

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Re: Sign of the times
« Reply #29 on: May 15, 2021, 11:36:10 am »
I recall reading an article that highway/street lights in white is easier for older people to see.  I can't find that article anymore.

But, it makes sense -- white comprises of the entire visible color spectrum.  Anyone with decreased sensitivity to any particular color can have the rest of the color spectrum to rely on.

The most common color blindness is red-green (8% of male, 0.5% female for Northern European descent according to Wikipedia), next to that is blue-yellow.  Yellow, orange, amber are colors are a mix of red and green, so it is unfriendly to decreased sensitivity to red-green.  The traffic light colors are even less friendly to them, yet red-green insensitivity appears to be the most common.

It may not make any difference to most of us, but I guess only until someone runs over your dog because the street is lid with yellowish lamps.

There's also a difference in sensitivity between photopic and scotopic vision, more bluish wavelengths have an advantage at low light levels. I think the real issue though is that so many things absorb orange light which leads to the effect of a bright source spraying light everywhere but the scene is not really lit up very well. The source itself looks very bright due to orange being close to the sensitivity peak of the eye but that just serves to drown out all the orange absorbing objects in the scene and produce a bunch of glare. There has also been a tendency to over-light, high light levels do not improve visibility over more modest levels, they just create contrast between brighter and darker areas. Modern regulations requiring full-cutoff luminaires that do not emit any light above 90 degrees also create a problem of needing more of them to create even illumination and even then you end up with bright pools under the source with dark spaces between. IMO they could achieve more effective lighting while still mitigating light pollution by using lower intensity sources and focus on providing even illumination. Less total light but more of it doing something useful.
Most colour blind people don't have reduced sensitivity to red or green light, because they have the same number of red and green cones as everyone else. The difference is their red, or green, cones are a slightly different colour, than normal, which makes their colour perception different.

Is there anyone here old enough to remember gas street lights? My father is in his mid 70s and remembers seeing someone going round lighting the gas lamps every night, when he was a child.
 

Offline vk6zgo

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Re: Sign of the times
« Reply #30 on: May 15, 2021, 12:40:21 pm »


On another trip to the UK, in 1974" I parked my pink Ford Cortina hire car in a smallish car park, & went to visit some people.
On my return, after dark, I couldn't find a pink Cortina, but there was a yellow one!

Not really that much of a hassle, as the key ring had the Reg number on it, but it had me going for a while.

Might have been pink elephants that were involved?

Nah!

The friends I referred to had a fish n' chips shop, & I visited them at work.
Nothing harder than coca-cola there, the "Red Lion" up the road had been knocked down, &, on general principle, I wasn't going to the pub in the railway station car park, that looked like a re-purposed toilet block!

Besides, the pink elephants would have looked like yellow elephants.
 
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Offline vk6zgo

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Re: Sign of the times
« Reply #31 on: May 15, 2021, 12:49:17 pm »

Coming back to streetlighting. Around here (Southampton UK) it was mostly LPS, with occasional HPS on major roads until maybe 5 years ago. Now residential areas are mostly fluorescent (!?) and dim or turn off from 1 am, most of the major roads are LED with some HPS left at big junctions.

SOTON was where I had my "yellow Cortina" experience.

I'm not sure of your vintage, but you might remember the "Golden Chippy", up the road from the railway station.
That was the one my friends ran.
 

Offline David Hess

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Re: Sign of the times
« Reply #32 on: May 15, 2021, 01:28:59 pm »
I think it varied a lot between urban, suburban, and rural areas.  LPS was common in rural California where I was born but I never saw them in any large suburban or urban areas.  The small towns in the 1970s still had a lot of them.

I think it was a California thing. I could swear I saw a few LPS remaining in San Diego I think it was as recently as about 10 years ago. Seems like I heard they were common in Arizona too, or maybe it was New Mexico, I don't even recall now. Up here in my corner I never saw them on public roads anywhere, ever. Rural and urban areas alike went from mercury vapor to HPS and over the past 10 years have been shifting to LED.

LPS may have been used in San Diego county because Palomar Observatory is near.  There were no observatories where I was.  I am sure what I saw was legacy installations which were eventually replaced with HPS and Mercury Vapor.
 

Offline madires

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Re: Sign of the times
« Reply #33 on: May 15, 2021, 02:02:48 pm »
I can't complain. A few years ago the street lights in my little town (rural area) were changed to LED and we have more lumen consuming much less power. Also the light footprint has improved, i.e. less dark spots between light posts. No idea of vendor and model, presumably the better ones. Regarding insects, the impact of the LED street lights doesn't seem to be larger than the old ones. Might coincide with the decline in insect populations.
 

Offline james_s

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Re: Sign of the times
« Reply #34 on: May 15, 2021, 11:58:53 pm »
Is there anyone here old enough to remember gas street lights? My father is in his mid 70s and remembers seeing someone going round lighting the gas lamps every night, when he was a child.

My friend visited Germany in I think 2010 and took a few pictures of some gas streetlighting that was still in use. I don't know exactly where they were but they resembled cobrahead style luminairs but with a row of gas mantles instead of a lamp in them.
 

Offline RichC

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Re: Sign of the times
« Reply #35 on: May 16, 2021, 12:59:56 pm »
The most common color blindness is red-green (8% of male, 0.5% female for Northern European descent according to Wikipedia), next to that is blue-yellow.  Yellow, orange, amber are colors are a mix of red and green, so it is unfriendly to decreased sensitivity to red-green.  The traffic light colors are even less friendly to them, yet red-green insensitivity appears to be the most common.

It may not make any difference to most of us, but I guess only until someone runs over your dog because the street is lid with yellowish lamps.
Sodium lamps are not a mix of red and green, they are a pure yellow (sodium lights have probably the narrowest frequency band of any lights in fact).

Also as mentioned colour blindness is about being unable to tell colours apart not being unable to see them at all.
 

Offline james_s

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Re: Sign of the times
« Reply #36 on: May 16, 2021, 04:55:24 pm »
Sodium lamps are not a mix of red and green, they are a pure yellow (sodium lights have probably the narrowest frequency band of any lights in fact).

Also as mentioned colour blindness is about being unable to tell colours apart not being unable to see them at all.

Remember that there are two types of "sodium lamps", low pressure sodium and high pressure sodium. The low pressure sodium lamps produce an extremely narrow band monochromatic yellow light, they have been very common in Europe and UK but are extremely rare in North America, they just never really caught on here at all.
http://lamptech.co.uk/Spec%20Sheets/D%20SLP%20GEC%20SOX90.htm

High pressure sodium lamps produce an orange colored light but it is fairly broadband, this is what almost anyone in this part of the world will think of if they hear "sodium lights".
http://lamptech.co.uk/Spec%20Sheets/D%20SHP%20Sylvania%20LU200.htm
 

Offline Siwastaja

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Re: Sign of the times
« Reply #37 on: May 16, 2021, 05:49:07 pm »
Good riddance.

LED streetlights are superior in almost every imaginable way, including the fact you see so much better with the same number of lumens.

Plus, you clearly are young and only pretending to be old and grumpy. The orange glow era was short. Before that, the dim cold white mercury vapor lighting was the norm.
 
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Offline Red Squirrel

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Re: Sign of the times
« Reply #38 on: May 16, 2021, 06:14:34 pm »
I don't think LED lighting itself is bad, but I don't get why they could not stick to orange/yellow for street lights as it's less harsh as far as making light pollution, and also keep the glass diffusers in place.  The orange light still lit up the streets without being harsh, and the diffusers made the light more spread out instead of lot of harsh spots. 

My city switched to LED years back and one thing I find is the light is more directional due to lack of diffusers so it's well lit under the street light but the spaces between are not lit as well.  The white light is brighter though, so there's that, but I don't think the purpose of street lights should be to try to make it super bright, but rather brighten up the area slightly enough to see.

 

Offline james_s

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Re: Sign of the times
« Reply #39 on: May 16, 2021, 06:24:42 pm »
I don't think LED lighting itself is bad, but I don't get why they could not stick to orange/yellow for street lights as it's less harsh as far as making light pollution, and also keep the glass diffusers in place.  The orange light still lit up the streets without being harsh, and the diffusers made the light more spread out instead of lot of harsh spots. 

The orange light was a bug, not a feature. It was something people lived with in order to get the high efficiency offered by a sodium discharge, it was never considered desirable and nobody thought it was an improvement over the nice white mercury vapor light we had before the switch to sodium. If the white light looks harsh it's probably because it's too bright. That awful orange light never really lit anything up properly so they used a LOT of light, and the LED replacements were sized to provide similar lumen output when in most cases they should have dropped it down a notch. The orange HPS light also does nothing to reduce light pollution, it's not monochromatic like LPS, and it's the monochromatic light that helps reduce light pollution because it can be easily filtered out.

The diffusers went away because of legislation meant to reduce light pollution by requiring FCO luminaires that do not emit any light at all above 90 degrees. This brings the unintended consequences of uneven lighting, hot spots and glare. IMO a better solution to light pollution would be to reduce the total amount of light emitted and try to have it as even as possible.
 

Offline Zero999

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Re: Sign of the times
« Reply #40 on: May 16, 2021, 06:38:57 pm »
Is there anyone here old enough to remember gas street lights? My father is in his mid 70s and remembers seeing someone going round lighting the gas lamps every night, when he was a child.

My friend visited Germany in I think 2010 and took a few pictures of some gas streetlighting that was still in use. I don't know exactly where they were but they resembled cobrahead style luminairs but with a row of gas mantles instead of a lamp in them.
I've read somewhere, there are still a few in London, preserved for posterity's sake, but when my father was a child, gaslighting was still widespread, in Warrington, Northwest England, near Manchester and Liverpool. Back then nasty coal gas, a flammable toxic mixture of carbon-monoxide, hydrogen and methane was use to light the streets, as well as piped into homes.
 

Offline penfold

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Re: Sign of the times
« Reply #41 on: May 16, 2021, 06:55:51 pm »
The one complaint I have with the LEDs is that without the diffusers, (living in a particularly hilly city) when driving up-hill they do appear quite dazzling and the more distant ones can be difficult to distinguish from an oncoming headlamp at first glance especially when there's a reflection from a window.
 

Offline PlainNameTopic starter

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Re: Sign of the times
« Reply #42 on: May 16, 2021, 07:13:46 pm »
Quote
when driving up-hill they do appear quite dazzling

When our lane was converted, I found myself squinting when between posts because of the dazzle. Now I don't notice, not sure why.

I think I am generally in favour of the white LEDs, but one thing I miss from the HPS is that you knew it was night time! Sounds daft, but then a big thing is made about monitors and phones dropping the blue at night (I disable all that stuff). Perhaps that's a hangover from years of sodium and incandescent interior lights - I notice that my preferred colour temperature for LED lighting has crept up since most of out fittings have been changed.
 

Offline Rick Law

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Re: Sign of the times
« Reply #43 on: May 16, 2021, 07:23:46 pm »
The most common color blindness is red-green (8% of male, 0.5% female for Northern European descent according to Wikipedia), next to that is blue-yellow.  Yellow, orange, amber are colors are a mix of red and green, so it is unfriendly to decreased sensitivity to red-green.  The traffic light colors are even less friendly to them, yet red-green insensitivity appears to be the most common.

It may not make any difference to most of us, but I guess only until someone runs over your dog because the street is lid with yellowish lamps.
Sodium lamps are not a mix of red and green, they are a pure yellow (sodium lights have probably the narrowest frequency band of any lights in fact).

Also as mentioned colour blindness is about being unable to tell colours apart not being unable to see them at all.

I understand that color blindness is merely unable to distinct the colors.  None the less, it does mean a degraded vision.

When you have two cars or of similar color, it is hard to make it out as two in low light.  Not being able to distinct 1/3 of the color, it may that distinction even harder.  It would be like: "That car split itself into two and one went straight and the other one hit me..."
 

Offline penfold

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Re: Sign of the times
« Reply #44 on: May 16, 2021, 07:39:28 pm »
Now I don't notice, not sure why.

You know what? I was thinking the exact same thing to myself. The first thought was that it was never a particular "problem" just a noticeable difference I just got used to or gradually adjusted my eye movement to avoid them and changed how I scan a road a when turning into a junction, I'm happy to believe its a perception issue rather than technical.

Driving in fog was a very noticeable difference especially where the orange made a useful contrast from the white or red of a car.
 

Offline james_s

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Re: Sign of the times
« Reply #45 on: May 17, 2021, 07:25:57 pm »
The one complaint I have with the LEDs is that without the diffusers, (living in a particularly hilly city) when driving up-hill they do appear quite dazzling and the more distant ones can be difficult to distinguish from an oncoming headlamp at first glance especially when there's a reflection from a window.

I live on a big hill and this still annoys me, I have gotten in the habit of looking away from where I know the streetlights are as I drive up the hill. Also a couple of trees have grown considerably since the LEDs were installed and that mitigates the glare too. The glare is a consequence of the FCO mandate and excessive light levels due to lumen standards that were created assuming HPS.
 

Offline Red Squirrel

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Re: Sign of the times
« Reply #46 on: May 18, 2021, 12:14:36 am »
I think the diffusers would actually REDUCE light pollution by making it more even instead of causing bright spots.

If you look at this long exposure for example you can see how the houses near the lights are very bright compared to ones not directly under, I guess it's hard to compare as I don't have a similar pic with the orange lights but I feel with a diffuser the lighting would be a bit more evened out.  Those bright spots are more visible from the air as well and the light reflects back upwards as the street also has a very bright white spot directly below the light.  The orange light was a bit more subtle and also less hard on the eyes.


 
 

Offline Zero999

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Re: Sign of the times
« Reply #47 on: May 18, 2021, 02:20:41 pm »
The most common color blindness is red-green (8% of male, 0.5% female for Northern European descent according to Wikipedia), next to that is blue-yellow.  Yellow, orange, amber are colors are a mix of red and green, so it is unfriendly to decreased sensitivity to red-green.  The traffic light colors are even less friendly to them, yet red-green insensitivity appears to be the most common.

It may not make any difference to most of us, but I guess only until someone runs over your dog because the street is lid with yellowish lamps.
Sodium lamps are not a mix of red and green, they are a pure yellow (sodium lights have probably the narrowest frequency band of any lights in fact).

Also as mentioned colour blindness is about being unable to tell colours apart not being unable to see them at all.

I understand that color blindness is merely unable to distinct the colors.  None the less, it does mean a degraded vision.
No it does not mean degraded vision, it's just more difficult to distinguish between some colours. Quite often it's very mild, in which case the person only struggles with unsaturated colours, in poor light.

Quote
When you have two cars or of similar color, it is hard to make it out as two in low light.
That's true for everyone, even more for those who are colourblind.
Quote
  Not being able to distinct 1/3 of the color, it may that distinction even harder.  It would be like: "That car split itself into two and one went straight and the other one hit me..."
What do you mean? You do realise that most people who are colourblind have as many colour receptors, as those with normal colour vision. They're just the wrong colour, which skews their colour vision slightly. It doesn't reduce their sensitivity to light.
 

Offline james_s

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Re: Sign of the times
« Reply #48 on: May 18, 2021, 05:22:48 pm »
I think the diffusers would actually REDUCE light pollution by making it more even instead of causing bright spots.

I agree, more even lighting would allow the use of less light to achieve the same result. The law says no light emitted above 90 degrees though which effectively bans drop-lens diffusers, and like many laws, it was based on good intentions but brings unintended consequences.
 

Offline Sal Ammoniac

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Re: Sign of the times
« Reply #49 on: May 18, 2021, 05:26:58 pm »
Why do we feel the need to light up everything at night? We're doing irreparable harm to many animal species that evolved in dark night skies. Human hubris at work...  :palm:
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