Thank you Eric, feel guilty posting an old one its all probably different up there now
Gav I was up al night 5 nights and captured many all isos, this was 1730 secs at 200 iso I recall may have stacked others too get this..had so many files, cropped sections, different processing , etc such I can not tell you truthfully exactly how I arrived at this ..it was one I worked up at 600 pixies to post on forums.
With your cameras you may be really surprised the detail you get on blow ups equating to a longer f/l back it off when (if) resolution really suffers..I recon you may just figure out stuff we have not thought of yet

...hey nice backdrop for wedding shots
alex