I've been playing around with the 6D's Multi-Shot Noise Reduction (MSNR) setting. This was taken with the 70-300L at 300mm and f5.6 and is a hefty crop. The dolls are on top of a bookcase in a fairly dark corner of the living room. ISO 8000. Not too bad, I think. I can't wait to try this on a real nighttime scene. Of course moving objects will be a no-no in this mode.