That's a stupid question. As much as you can get, until you run out of optical
quality.

Sorry, Jeff. I worked professionally with large format cameras for Finely Photo
and as still photographer for catalogue. Cropping is something to be used
sparingly. Learn to compose your photos. 8 mp is just not going to show up
unless you have professional printing gear. On my my very nice HP photo
printer, 8X10s look fantastic from G2, G5, Z1 and even the little Sony U30 can
make a reasonable print at that size. 3mp is really all you need and anything
above 4-5 is just silly. Sell the G5 as I am. These 3 and 4x lens models are
about to go the way of the dinosaur.

RB