I downloaded the hi res image, 280mb of Tiff file !
Heres an appropriately resized version for the east states.
Legend:
Colours correspond to ratios between the artificial sky brightness and the natural sky brightness of: <0.11 (black), 0.11-0.33 (blue), 0.33-1 (green), 1-3 (yellow), 3-9 (orange), >9 (red).
In real terms, once you get into the blue region things are starting to get good for viewing faint fuzzies.
http://gar.customer.netspace.net.au/scope2/Auslight.jpg