[actionfromafar]

It's exactly the other way around. Now I'm afraid this is some kind of common misconception, like "not only are LEDs great when it comes to efficiency, they don't pollute the light either!"

[Izkata]

The ones around here direct the light downwards at the street instead of almost-every-direction like the old ones did, so it's kind-of true that the LED ones have less light pollution (I know I'm getting a hell of a lot less light into my windows), but it's because of the lamp shape and not that they're LEDs.

[throwawayben]

yes this was my observation, since the ones outside my house were replaced I have much less light into my house and I can see the stars. I assumed it must be some factor of the LED design that makes it easier to direct downwards though

[actionfromafar]

For astronomy, the pollution upwards is the problem.

For insects and mammals and birds, it's the spectrum, the colour, which is the problem.

[actionfromafar]

Here it's the other way around. The new shapes are bonkers.