Earth Hour 2012

[solissydney]

Image taken from Sydney Observatory before and during Earth Hour.
The photo speaks for itself.

[astronobob]

Interesting Ken, a big difference, yep. I once did this from the hills aside the Gold Coast Qld and No difference detected, Lol ? ?

[solissydney]

Did you over exposure long enough from a normal exposure do you think Bob?

[astronobob]

Interesting point Ken, cant say I did, was a few yrs ago, thanks for pointing out, I should try again with this in mind mate !

Your shot is from the Sydney Observatory, In 2000, I met a chap that held mirror making classes in that building, John someone ? lived in Watson Bay, on the South head land ?

[solissydney]

Can't say I recall a John from Watson Bay.
I do remember someone teaching mirror grinding there living in Seven Hills
Ken

[astronobob]

Prob the same bloke & may have moved ? ? He used to have an advert in the old astro mags in them days, I purchased optical grade abbrassives, Cerium oxide polish and tropical polishing lap ingrediants from him, very good quality too ! He also made optical flats and lenses !

[bloodhound31]

WOW! What a difference to the sky above! You can see the stars clear as mate!

Baz.

[solissydney]

The stars?
I had not even thought about the stars. I had one thing on my mind only, that
was the wasted light causing sky glow. But, as you pointed out there are some stars there, i think?.
The exposure for the 'before image' was 3 seconds and
the 'during', 1 second. both at 1600 ISO.