There is ample detail in the 21.1MP Canon EOS 1Ds Mark III images (EOS 1Ds Mark II.1?), but each and every image seems “strained” compared to the 12.1MP Nikon D3, and color rendition just doesn’t satisfy the same way, even with premium Zeiss ZF glass. The D3 offers higher overall image integrity without the extreme resolution of the 21.1MP 1DsM3. But oddly enough, I hardly ever give a damn about the extra 9 megapixels—my visual reaction favors the D3. I find this striking given my historic quest for more and more resolution—high pixel quality at 12MP is the real deal, though it might mean that 36 X 24" prints still favor Canon’s offering. Perhaps the next generation will deliver high quality at 21 or 24 or 30MP, but that’s likely a few years off. For now, the Nikon D3 is the “poor man’s medium format digital back”.
If you savor quality over quantity (Spitzer?), favor the Nikon D3 over the Canon 1Ds M3 unless you believe the stupidities and warmed-over marketing drivel expressed in the April 2008 Shutterbug in the “review” of the 1DsM3. For that matter, per-pixel image quality of the 10.1-megapixel 1DM3 is definitely better than the 1DsM3 (the 1DM3 being my previous favorite DSLR about which I’ve written a great deal in this blog). Still, there should be no misunderstanding—the images from the 1DsM3 are very good indeed—that’s “good” but not “great”. But each of us reacts differently, and perhaps after spending $8K for the 1DsM3 most users will succumb to cognitive dissonance and be at peace with their expenditure, knowing theirs is the biggest.