NEW LED STREET LIGHTS

[DAVE AMENDALL]

Hi All, We have just had the new Led street lighting installed. at least although bright it shines  on the ground. My back garden is dark being protected from them by the house. Any one recommend a light pollution filter to combat these leds. I haven't a clue what wave length they are................regards Dave

[wavydavy]

Quote

 

Aparently you cant filter LED, which some spell the death of asto-imaging or dark sky preserve. The good thing is there point directional and don't scatter upwards like the old style sodium. Im sure someone on here may dispute if it can be filtered or not.......but its my understanding you cant.

[Mr Spock]

You can't filter LEDs unfortunately. They are supposed to be better but here in Sheffield where we have almost replaced all the old type lighting the sky is much brighter than it was

[DaveS]

Narrow band is your only hope, and the narrower the better.

[Physopto]

These new types are Full Spectrum. I am not sure what that entails now as there are several different makers. Each will be ever so slightly different in what wavelengths they emit in. Narrow band may be a complete waste of money! I am dreading it where I live.

If actually they are full spectrum, I would just put the cap on the end of the scope and go to bed!!!!

Derek

 

What is different between 3w full spectrum led with tranditioanl HPS lamp .

 

 

[Physopto]

Here are some graphs of other other types. There will be many more with much worse (for us) emissions.

 

[whooshbang]

so does this mean all the flowers will bloom in the middle of the night? It's gonna do wonders for my runners beans if so!

[Tonynexevo925]

They have been installed on the main road through my village and they're great... BUT they are now starting to replace existing sodium lamps on side streets one by one as required. 

BIG problem for me as they create a really bright point of light in the distance 100m or so and from my observing spot in the back garden I used to have two distant sodium lamps in my eyeline which was tolerable. These new LEDs are so bright and in my eyeline that they are incredibly distracting. My real concern is in winter with no leaves on trees it will be much worse!!!

I'm considering making some sort of shielding that can be put up and taken down as required though as it'll need to be about 10 feet high I am unsure about stability. 

I wonder why the eye is drawn to points of light even when the brain is saying "no, don't go to the light!" 

Roll on summer and more leaves on trees for me. 

[chiltonstar]

Note that all the types have a dip in emission around 490 - 500 nm. If you use a Lumicon UHC filter which has a bandpass centred around this point, I think you should gain considerably wrt removing LP. You would gain more by cutting off the red end of the UHC as well.

Chris

[Physopto]

There is not much left in the visible spectrum in between the LED peaks.

[DAVE AMENDALL]

Thanks guys for all your comments. As said,the Autumn and winter skies will be the fairest test. I have a Lumicon UHC filter which I have only used on nebula in the past and tend to use the  Lumicon Deep Sky filter which has been great with the old sodium lighting. Nothing to lose by using the UHC  in the LED situation and will give it a try.................regards Dave