Show us your light pollution..

[WingnutR32]

Was outside last night under the full moon, staring in awe and grabbed a few photos with the Canon 60D + 18-55mm kit lens.

I took this 30sec exposure to get the pointers in line with the basketball ring and was amazed at the amount of light pollution you can get. The orange tinge to it is from 2 street lights directly behind me on the road (right where my observatory is going (who has an air rifle)).

[h0ughy]

http://www.iceinspace.com.au/forum/showthread.php?t=65759&highlight=light+pollution and http://www.iceinspace.com.au/forum/showthread.php?t=62298&highlight=light+pollution

[WingnutR32]

It really is just crazy. I can deal with one street light behind me, but the other one is only about 15 meters away from the observatory shining straight down onto the site. I wonder if it is legal to add some 'lens shades' to a street light?

A bummer about the dog track being so close to you as well h0ughy. Has the neighbors put blinds up yet?

[h0ughy]

no

[Moon]

My story:
http://deepspaceplace.com/lightpollution.php
James

[koputai]

Interesting read James, I was going to suggest that we have an hour one night where IIS'ers all take a 30 second shot straight up with a 50mm lens at f/4, so we could compare sites all across the country at the same time. Pretty much what you did.

On your page you say "I also did not pay enough attention to the focus and this has influenced the measurements to some degree". Wouldn't slightly out of focus be a more accurate test, as it would average the values across the frame more evenly?

Cheers,
Jason.

[WingnutR32]

Wow, impressive (yet crappy, for the lights being there) results, James.

2 of the top photos in my first post were done at 30seconds and ISO 3200.

I will definitely have to organise a time to head to Orroral Valley with Gem and a few others. Even if I just take the bino's and a fixed tripod.

[Moon]

My test was a quick and dirty (and I was a bit sleepy), so I don't want it to be misinterrupted as highly scientific study. Having said that, I wanted to ignore the stars, and only measure the background brightness, so I used the 'mode (http://en.wikipedia.org/wiki/Mode_(statistics))' function to measure the most common value. I was worried that if the stars weren't in focus, this would spread them out and increase the reading a bit.
James

[ballaratdragons]

When I find out what 'Light Pollution' is I'll post an answer. :P

But in the meantime, here is a pic from my town ;)
Canon 350d, single 10 second image, iso 800, kit 18~55 lens.
I had to illuminate the sign so it could be seen.

(HINT) move to the country

[WingnutR32]

That is phenomenal, Ken! I didn't think the Coalsack would be so obvious through such a short exposure and the kit lens.....

In fact, I cannot even see it naked eye from my place.

[ballaratdragons]

Yes Sam, very dark sky really makes that much difference.
I tried to keep the image matching the naked eye experience here. Otherwise a longer image would've shown what we can't seen naked eye.
Anyone who has been to SV camps would be familiar with the sky in my pic :thumbsup:

[mill]

Yeh you stole it from us :lol:
Now you are keeping it and we have to come over to see it :hi:
I will have a look if i can make a pic tonight from my back yard.

[Stevec35]

I did manage to get a street light that shone directly on my observatory changed to a cut-off fixture that improved the situation at least 70-80%. It did take a while though.

Cheers

Steve