At 100 percent magnification in Lightroom, the Nikon's RAW files appeared only slightly sharper than those we shot with the 21.1-megapixel Canon EOS 5D Mark II, despite its three-megapixel advantage. (See D-SLR Shootout, May/June.) But the D3X's superb JPEGs were nearly identical in fine detail to its RAW files, while the Canon's were slightly soft. And while comparisons also showed no significant differences in noise up to ISO 400 among our full-frame sensor D-SLRs, the Nikon exhibited superior shadow detail that could be further brightened with much cleaner results than the others.At higher ISOs, the D3X is no match for the Nikon D3, which owes its low-light performance in part to fewer and therefore bigger pixels. The EOS 5D Mark II also bests the D3X in that respect. But we found D3X's tighter, film-like "grain" more pleasing than the blotchier noise and linear banding sometimes visible in the EOS 5D Mark II's deep shadow areas.