I'd forgotten about noise. That said it still is based on me as the limiting factor, if the exposure is spot on then noise shouldn't be a problem, I have a 18X12" print from my 10D shot at iso 1600 1/10 shutter speed that is essentially noise free due to the exposure being totally correct, that print still amazes me and I've sold a lot of it. With my 1Ds, and this backs up what Jonathan told me, if the exposure is 'on' then the noise is fine, including iso 800, but with 400/800, the moment you move the exposure or brightness in ACR, even by .30-.50 the noise leaps out at you.