Measuring light pollution

[Imme (Jon)]

Radiance.....what is it and how do I compare it to other sites?
Looking at a reputable light pollution map and clicking on my backyard I get a Radiance figure of 0.17.....what do I compare this to?
How do I put this number in perspective?
Just by walking outside I know that it is good.......it's very dark and I can't discern any pollution.
What level of "radiance" are the rest of you taking photos in?

[billdan (Bill)]

I haven't heard of that terminology before (radiance) when it comes to light pollution.

You can purchase a Sky Quality Meter (SQM), which will measure the quality of the sky above you, generally in the suburbs you get a reading of 18 and over 21 at a dark site.

In the USA they describe the sky quality as colored zones, with a red zone being inner city, orange/yellow for suburbs and green/blue for out in the country.

Where I live (last time I checked), my side of the street is a yellow zone, but the guy across the road is in a green zone.

Cheers
Bill

[Imme (Jon)]

Sounds like you may need to make an offer on the house across the road!

Thanks for th eon for anyway....I've done some mor eresearch and puns radiance is a logarithmic scale and basically useless as any form of measure.

......but I've come across another measure which works really well......walk outside and open my eyes......if I can see a good number of stars with the naked eye then the going is good hahahaha.

[N1 (Mirko)]

Couple of links to get you started:

https://www.globeatnight.org/
http://cires.colorado.edu/Artificial-light

Star counting is not as silly as it sounds