Upgrades to street lights, making LPR filters obsolete?
Hi all,
Just wondering, with all the street light upgrades around the world to new cost-effective LED types, will this render LPR filters less functional or obsolete?
Since the new lights will most likely be of a different Spectral Wavelength, LPR filter tuned to block Sodium Spectral Wavelengths probably will not work anymore. Anybody got data or reference to this problem and how it will affect Amateur Astronomy?
I have wondered that myself. White "Lighting class" LEDs operate much like a fluoro tube, in this case most of them produce blue light and use mixtures of phosphors in the optics that are excited by the blue light to mix and create a white light LED.
Perhaps LPR filters for fluoro lights may be effective? The white LEDs I think usually mix only a handful of wavelengths together from different phosphors to produce visually white light so filters that stop only those wavelengths might be pretty effective.
While the color of LED light used could pose a problem, the naturally narrower beam should lead to less light pollution spilling over into backyards - the new lights could be really good or really bad depending on the design.
Personally I'd be happy if they just got the angle of the beam right regardless of the wavelength.
There is that. The characteristics of the LED lamps usually makes each LED a lot more directional than traditional lamps. It would be interesting to see a LED street light luminaire and a traditional one like a mercury vapour light side by side to see the difference.
Despite the new LED streetlights, they'll still have to shade the lights properly to reduce stray light going everywhere. Also, don't expect councils out here to go out and install these lights. They'll say they're too expensive and then take 500 years to do anything about them at all, if they ever do.
Also, don't expect councils out here to go out and install these lights. They'll say they're too expensive and then take 500 years to do anything about them at all, if they ever do.
Unless there's a federal streetlight stimulus - then they'll all get replaced in two months, but half of them will be pointing up
I have wondered that myself. White "Lighting class" LEDs operate much like a fluoro tube, in this case most of them produce blue light and use mixtures of phosphors in the optics that are excited by the blue light to mix and create a white light LED.
Perhaps LPR filters for fluoro lights may be effective? The white LEDs I think usually mix only a handful of wavelengths together from different phosphors to produce visually white light so filters that stop only those wavelengths might be pretty effective.
Good point, I don't know the exact wavelength of the upgraded led types but if the people who are overseeing those operations, have any idea of what they are doing, they would stick to a wavelength with amber hues/colour, and hopefully will not render LPR filter investments useless.
It's been researched that these amber wavelengths are more suited for long periods of focus for humans. Such as the old amber and green computer monitors. It was found that these monitors are easier on the eyes and are more comfortable to view.
While the color of LED light used could pose a problem, the naturally narrower beam should lead to less light pollution spilling over into backyards - the new lights could be really good or really bad depending on the design.
Personally I'd be happy if they just got the angle of the beam right regardless of the wavelength.
Yep, them planes needs lights so they's can find their ways
Traffic lights are already being replaced here in Australia. Councils won't pass up the money saving benefits of LED's. They practically run on nothing compared to incadescent/fluro etc...Even if it's a slow change, they will eventually end up doing it I think.
The Power Company came and put this new light up just outside my house a couple of months ago ..... this one ' emits ' a very white light .... and screwed up everything for visual use .... so much light pollution .... I can't view from my back yard ... there are toooo many trees that block the sky. .... When I do use my scopes ... my back is towards the street light so as to minimize all the stray light. .....
The Power Company came and put this new light up just outside my house a couple of months ago ..... this one ' emits ' a very white light .... and screwed up everything for visual use ....
I've got two accross the street from my backyard; I hide behind a shed to view but light reflects back at me from the wall of our house - more than once I've thought of painting the wall matt black. I can still see Milky way/LMC/SMC but galaxies are almost a complete loss. Shielding on the lights or more directional lights (LED) would make a big difference.
Traffic lights are already being replaced here in Australia. Councils won't pass up the money saving benefits of LED's. They practically run on nothing compared to incadescent/fluro etc...Even if it's a slow change, they will eventually end up doing it I think.
You don't know most councils....even doing something as simple as replacing the broken globes in streetlights with some councils is too much like hard work and wasting money. They'll look at the costs to install LED lighting and run the other way, even if it appears cheaper. Simply because they have to spend money to do the work.
I've got two accross the street from my backyard; I hide behind a shed to view but light reflects back at me from the wall of our house - more than once I've thought of painting the wall matt black. I can still see Milky way/LMC/SMC but galaxies are almost a complete loss. Shielding on the lights or more directional lights (LED) would make a big difference.
They talked about shielding streetlights years ago but wouldn't do it because they said it would cost too much. Might also lower the globe's lifespan as well (getting too hot).
I've got two accross the street from my backyard; I hide behind a shed to view but light reflects back at me from the wall of our house - more than once I've thought of painting the wall matt black. I can still see Milky way/LMC/SMC but galaxies are almost a complete loss. Shielding on the lights or more directional lights (LED) would make a big difference.
Class Action on this one ( you and me ) ... what'da reckon Tony ... !!
What are our chances ....
I've used a black shroud to minimise stray light at the eyepiece, stops reflections etc.... Just pop it over your head and the eyepiece.
An extra long dew shield may also protect the primary lens from stray light entering the primary and stray reflections also. Can't do much about skyglow from white light though. If there's the slightest amount of dust or fog in the air, it will reflect back onto the primary.
It's hard to get good night vision when there is stray white light about, ruins it. I suppose a good pair of red lens spectacles would help. When you are ready to view just take them off under the black shroud.
If those street lights had a polarised coatings on the transparent covers, they could still illuminate the street (keeping councils and concerned citizens happy) but, if you then use a polarised filter to block it at the telescope....That could be an option, but councils won't help the Astronomy community on this one I don't think.
the power company came and put this new light up just outside my house a couple of months ago ..... This one ' emits ' a very white light .... And screwed up everything for visual use .... So much light pollution .... I can't view from my back yard ... There are toooo many trees that block the sky. .... When i do use my scopes ... My back is towards the street light so as to minimize all the stray light. .....
..... this one ' emits ' a very white light .... and screwed up everything for visual use .... so much light pollution .... I can't view from my back yard ... there are toooo many trees that block the sky. .... When I do use my scopes ... my back is towards the street light so as to minimize all the stray light. .....
