Question about the new LED street lighting

[davelew.livejournal.com]

This is a long shot, but there's enough random information on this community that I thought somebody might be able to help.

The city of Somerville is switching from old sodium vapor street lights to new, more energy efficient LED street lights. That's great and I support it, it's good for the environment and for the city's finances. The problem is with my telescope. I have a filter for my telescope that cuts out light pollution from old-style lights, by blocking light at precisely the wavelengths of the emissions spectrum of sodium atoms. Unfortunately, that filter does nothing for the new LED lights. It's nice to have a filter for urban astronomy if you're looking at anything dimmer than the moon, and I don't know what filter(s) to get.

So, here's my random question: Does anybody know the emissions spectrum of Somerville's new LED lights? Or even a single particular wavelength that they don't emit? I'd even be happy with a model number so that I could contact the manufacturer.

Comments

[clevernonsense.livejournal.com]

I'm curious where it says they run at the same power? My home town is in the process of switching slowly (as old ones break they get replaced) and the LED lights purportedly use less than half the energy and are simpler to replace if something goes wrong (simpler but more expensive). I'm sure there's a million options to choose from.

But yeah, "White LEDs" run on a rather broad spectrum unless particularly designed to be lower light pollution lamps (which I prefer, but they don't really light up dark street corners very well so maybe not a good idea for a city with a bit of street crime).