ISO 25600 - Noise? What noise??
I see... GRAIN! I've had my 5D mkIII for two days now, and shot this while messing about in the kitchen while my son was watching something on the iPad. The first think I noticed when I opened the images in Aperture (at 100%) was the out-of-focus toy aeroplane in the extreme corner of the picture:
It's worth magnifying up to 100% to see the grain properly! I'm really excited - I think I can really do something with this once I've mastered the camera. I'd never, ever have thought I could get anything useful out if ISO 25600! It's just about as exciting as seeing a good print appear in the developing tray for the first time! Almost.
Apologies for the self-indulgent post. Thought I'd share, since many people seem a bit preoccupied by noise-reduction.