Letter from the council....

[Uranium235]

Today I received a letter from the local council stating that they are about to install new efficient "white light" steetlights. So would I be right in guessing that they're going to be of the LED ilk?

What are the emission lines of these lights? And what implications would it have for imaging? I'd assume they will make my clip filter redundant

Hopefully, they will also replace the fittings with something a bit more directional, and not just throw all those nasty photons up into the sky. I might get in touch with them for some more detail.

So, it looks like I'll be doing more narrowband from now on.

[Smeg]

Have you tried emailing the Council asking them for more info on the lighting?

[Uranium235]

No email address on the letter, but theres a phone number - I will give that a try tomorrow.

[Smeg]

I found this...

Get in Touch

And this..

http://www.worcestershire.gov.uk/cms/street-lighting.aspx

and this...

http://www.worcestershire.gov.uk/cms/street-lighting/frequently-asked-questions.aspx

[Psychobilly]

I found these...

http://www.asdi.com/documents/spectral-signatures-of-nighttime-lights.pdf

The Complete Guide to LED Street Lights ? Part I - MyLEDLightingGuide.com

Peter...

[Deneb]

They have changed the lights in my street a couple of years ago & their a lot better then those old sodium lights, from seeing only 15 stars I can now see 50-60 stars on a good night....

Nadeem.

[Uranium235]

Thanks Peter, thats good reading. According to that the LED version (if full cutoff), have a lot less leakage.

But, after studying the emission lines, its not looking so great in terms of being able to block it (if needed) as they seem to have quite a broad band from 450 - 650nm, which is more or less everything.

Nadeem, lets hope they are as good as you say they are (fingers crossed!)

Rob

[Psychobilly]

my experience of them .. is that for imaging they are ok... they might be brighter underneath but a lot darker above... although you can get backscatter of damp ground but still a big improvement

[pete_l]

We got "done" a couple of years ago. The lights are definitely broad-band, so can't be filtered. However since they have hardly any upwards scatter I reckon my skies are now half a magnitude darker than before. I've gone from somewhere between 3.5 - 4, depending on the conditions to about 4.5 on the best, clearest nights.

[Psychobilly]

This example is from Southgate Carpark on The South Gower Coast

[Uranium235]

Not so bad it seems, if it improves the sky then I wont be complaining. Its due to happen during October, so I'll find out soon enough

[Smeg]

Perhaps get a local astronomy club to talk to the council?

I am fortunate in one hand living up a mountain with zero light pollution, on the other hand, internet sucks, so it comes with its costs and downsides.