The Royal Greenwich Observatory & Sky at Night's competition is here: nmm.ac.uk/astrophoto (http://nmm.ac.uk/astrophoto)
The rules say they prefer images of 6 megapixels or more, so the winner can be printed at A2 size.
Mark
Well that pretty much rules out anyone who doesn't image with a DSLR or a cooled camera that costs less than £3.5k... And if you image with an 11M pixel mono camera then you're in with a pretty good chance.
we could now launch into a discussion around upscaling...
Robert,
A mosaic would work well ;-)
Mark
I'd have to do an upscaled mosaic, should give the four cores a bit of a workout before crashing...