Author Topic: Los Angeles LED Lighting Effects  (Read 170 times)

Adam Rice

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Los Angeles LED Lighting Effects
« on: December 27, 2017, 11:12:17 AM »
New York City is going forward with the LED lighting I believe in 4300K range.  I believe LA updated to LED street lighting in the past few years.Are there any astronomers in the LA area who can comment on conditions since the upgrade?  Is the light pollution worse/same/better?I want to get an idea what to expect going forward.  BTW, I have signed the petitions, sent the emails etc to the city.thanks,lb



Jeffrey Hunter

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Re: Los Angeles LED Lighting Effects
« Reply #1 on: December 27, 2017, 12:07:08 PM »
It's awful   We used to have low pressure sodium in our neighborhood and at least I could make out a few major constellations. Now with LED street lights, about 30% of the stars disappeared...I live in Granada Hills (Red zone at the north end of Los Angeles)

Dave Jones

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Re: Los Angeles LED Lighting Effects
« Reply #2 on: December 29, 2017, 04:50:35 AM »
It's no better or worse from what I can see in fact I'm absolutely shocked anything even improves here! LA is horrible when it comes to taking care of itself. I've never seen a city that takes in so much revenue, yet does nothing to get its act together although Oakland is by far the worst when it comes to street garbage. I don't think they've ever heard of community service. With regard to LA the stop light system is so bad, it's absolutely frustrating. There should also be strict laws against all the development of apartment complexes as well. The place is packed like sardine can with more and more people so I wouldn't expect lights to fade. For myself though, white light doesn't bother me at all in fact I keep white lights on while I view only because I'm viewing other targets than deep sky. I suppose that's why I'm so fond of Burnham's Celestial Handbook as an observing guide. It focuses on a ton of targets that are hardly affected by light pollution. All I care about mostly is seeing. As long as seeing is good, it's a great night! LA is and never will be anywhere remotely close to even considering a reduction in light pollution. LED's are a great solution though to the amount of power consumption most lights here use.

fibcapoti

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Re: Los Angeles LED Lighting Effects
« Reply #3 on: December 31, 2017, 05:17:11 PM »
Welcome to Cloudy Nights Ibilello!Even tho I have a son who has lived in that area for 6 or 7 years he doesn't complain about the LP. But he does like to go into the local mountains to camp. A couple of weeks ago he called to ask about what telescope to buy as the stars were so bright when he camped...and he wanted to have a close look at the babes on the beach. I happily sent him a 65mm ED spotting scope and tripod and a couple of eyepieces.This does not directly address your question but maybe my son will finally figure out why his dad complained about unshielded outside lights these many years.Good luck.

bronedproudem

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Re: Los Angeles LED Lighting Effects
« Reply #4 on: January 03, 2018, 11:49:36 AM »
My city has started to install blue LEDs .They are shielded better than the old Cobra head sodium lights they replace . The light scatters more especially with snow cover so there is no gain in star visibility. The lights need to be installed exactly level or they cast light to the side .the resulting glare is very harsh. The city is applying an exact drop in replacement"pave the cowpath approach" so if the pole is not perfectly erect you get glare.There is no review  as to whether the light helps motorists pedestrians or whatever.

adpotabza

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Re: Los Angeles LED Lighting Effects
« Reply #5 on: January 08, 2018, 01:07:17 AM »
Interesting  article  mentioning some possible health related risks of LED lighting and light pollution.

Spectrum chart for LED lighting shows it's a much broader spectrum, but still controllable with filter use - narrowband filter use.

Peak at 460nm where nearest H-Beta lines fall at 486nm and OIII at 500.7

All upper transmission lines of NII, Ha, SII would be very easy to filter out.

I suspect 3-7nm narrowband filtering of both OIII and Hb would allow for cutting through newer LED's, but this article at least shows some studies have been started.

brascharnide

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Re: Los Angeles LED Lighting Effects
« Reply #6 on: January 08, 2018, 07:48:22 AM »
Quote
It's awful   We used to have low pressure sodium in our neighborhood and at least I could make out a few major constellations. Now with LED street lights, about 30% of the stars disappeared...

I live in Granada Hills (Red zone at the north end of Los Angeles)

Low pressure sodium is a lot easier to filter out in an LP filter transmitting from 589 - 589.6nm making a reject filter easy to make.

New LED's have such a broad spectrum with some peaks, but no narrow emitting spectra so whichever filter you use will have some amount of bleed through on LP. Because it is so energy efficient and so broad in the visual spectrum makes these attractive to non-astronomer politicians.

They do leave options open for electronically assisted viewing in the Red and Deep Red spectrum.

3-7nm Ha will take out almost all LP with very slight bleed through and 5nm SII with even better results.

Trick is to use device that boosts these to acceptable visual levels.

The real trick is to get people to listen to benefits of specifically directing light downward in concentrated areas.

I'd be curious to see how much difference there is in energy of reflected LED reflecting up off the pavement to what is projected down at the pavement.

Street lighting isn't going to be less for big cities like LA, but could be controlled for the cost of a small bite in savings over mercury or sodium lighting

Tom Durham

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Re: Los Angeles LED Lighting Effects
« Reply #7 on: January 08, 2018, 12:59:00 PM »
Quote
New York City is going forward with the LED lighting I believe in 4300K range.  I believe LA updated to LED street lighting in the past few years.Are there any astronomers in the LA area who can comment on conditions since the upgrade?  Is the light pollution worse/same/better?I want to get an idea what to expect going forward.  BTW, I have signed the petitions, sent the emails etc to the city.thanks,lb
You won't believe the reduction in the light dome above the horizontal plane of the lighting head !  As with where I live it should increase your seeing by a couple of classes on those great seeing nights, don't let anyone tell you differently before you try it. I will say that with a city as large as where you live commercial lighting will still have quite a detrimental affect as private installations are not normally legislated / controlled by the municipality as part of it's upgrades due to incurred costs. Keep your fingers crossed !

Bilal Luck

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Re: Los Angeles LED Lighting Effects
« Reply #8 on: January 09, 2018, 08:48:34 AM »
LEDs should have low melting temperature so people must be careful with parabolic mirrors during the day around them...

Seth Mamidi

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Re: Los Angeles LED Lighting Effects
« Reply #9 on: January 10, 2018, 04:05:12 AM »
LED's can sit on top of a pole over a concrete drive on a 120 F day and still function properly.High temp is not a problem.

dsepinumer

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Re: Los Angeles LED Lighting Effects
« Reply #10 on: January 11, 2018, 02:19:14 AM »
FYI, New York Astronomers - I was on the Cross Island Parkway Last night and noticed that the lighting has been updated to what I believe is the new LED lighting.

IMO, the new lighting was not as bright as the Sodium Vapor lamps and the lamps appeared to be better shielded so there was less light escaping up.

We shall see how LP is affected going forward as the installations continue.

lehroldwebbdep

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Re: Los Angeles LED Lighting Effects
« Reply #11 on: January 11, 2018, 11:42:57 AM »
Quote
<p class="citation">StarWolf57 said
It's awful  We used to have low pressure sodium in our neighborhood and at least I could make out a few major constellations. Now with LED street lights, about 30% of the stars disappeared...
I live in Granada Hills (Red zone at the north end of Los Angeles)

Low pressure sodium is a lot easier to filter out in an LP filter transmitting from 589 - 589.6nm making a reject filter easy to make......

[/quote]

Alas, LPS is going the same way as all other dischargelighting .... the same way as the Dodo..... extinct.

In very short order, a year or so, and there will be nothing for anyone to buy except LED. There's just no money to be made in continuing production of the old lights.

ridafimist

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Re: Los Angeles LED Lighting Effects
« Reply #12 on: January 11, 2018, 02:30:21 PM »
Quote
FYI, New York Astronomers - I was on the Cross Island Parkway Last night and noticed that the lighting has been updated to what I believe is the new LED lighting.

IMO, the new lighting was not as bright as the Sodium Vapor lamps and the lamps appeared to be better shielded so there was less light escaping up.

We shall see how LP is affected going forward as the installations continue.


 I've still not found out the fate of the NYS anti-LP Bill, passed overwhelmingly by the Assembly and sitting on the Governor's desk.

As my local news paper recently reported: a discussion by the Town Board of the town just south of me included a question by a board member to a representative of a LED streetlight installer: "What do we do if there are complaints about the new LEDs being too bright?" His answer: They are easy to turn down in brightness. That would be something of interest to those working toward local LP control legislation. Also, I believe that all big cities will eventually go with computer controlled 'smart lighting systems', with the brightness of each light controlled according to local conditions.

 Also, with respect to the local town changing over to LEDs: They have installed a test strip on one street so that citizens can check them out and comment!

 R

ifaclidis

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Re: Los Angeles LED Lighting Effects
« Reply #13 on: January 12, 2018, 01:09:23 AM »
FYI - Almost all of the Los Angeles new LED street lights replaced cobra head HPS lights (the whitish-orange ones) with "near" cut off LED lights. City of LA has never had very many of the LPS lights (the long tube yellow ones that are so common in North San Diego County).

Here is a link to before and after pictures (at the bottom of the page):

http://bsl.lacity.or...news-media.html

The City has also been experimenting with dimming the lights during late night hours on a few streets (but have not decided on a permanent dimming plan yet)

Vincent Reside

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Re: Los Angeles LED Lighting Effects
« Reply #14 on: January 12, 2018, 01:10:18 AM »
Quote
FYI - Almost all of the Los Angeles new LED street lights replaced cobra head HPS lights ......

Here is a link to before and after pictures (at the bottom of the page):

http://bsl.lacity.or...news-media.html

The City has also been experimenting with dimming the lights during late night hours on a few streets (but have not decided on a permanent dimming plan yet)


Interesting photos! While they don't provide a lot of info on the impact on LP, at least the ones taken from a high angle show that the new lights no longer thro light upward like the old ones did. On the other hand, the color is bluer and the ground coverage of the light is wider (not necessarily a bad thing if the total upward directed light is less).

Hopefully the dimming experiments will how that there is no safety issue. If they had an advanced computer system, it would keep the light level high during adverse conditions, like rain storms.