One thing I did notice for the shot I took of Beth Bruder holding up the copy of my wife's book on the blog link I mentioned in the previous post, was that I had the iso at 400, and shot the photo just using the window light and ambient tungsten in the room. It was quite noisy at iso 400. This was a raw file. I presume the noise issue is because of sensor size? I hardly get any noise on my 40D at iso 800.