Quote Originally Posted by Atomhot
hmm… The noise on a FF ( 5Dmkii ) @ ƒ4 should be less than the noise on a 1.6 ( 7D ) @ ƒ4 for the same lens, shutter, aperture et al.

Yes, that's what I intended to say; sorry if I wasn't clear. In other words, f/4 on FF has less noise than f/4 on 1.6X, and f/4.5 on FF has the same noise as f/2.8 on 1.6X (if the performance per area is the same, as in the case of the 7D and 5D2).