Quote Originally Posted by Daniel Browning
Canon changed the way tweener ISO are handled in the 5D2. Now they are 30D-style "digital" tweeners instead of analog tweeners like the 5D Mark 1 and 1D series. That's actually a good thing, because the analog tweeners on the 1D series and 5D1 are implemented by a separate gain amplifier that adds enough of its own noise to make it just as noisy as pushing a lower ISO.

Hmmm. I wonder if they could get even lower read noise by pusing that even further... maybe get rid of iso 200, 800, 3200 and leave only 100, 400, 1600.


As an aside, I believe that read noise always decreases less than linearly. That is, you'll always get lower noise (but lower dynamic range, too) by doing a single low iso exposure than several high iso ones (ie, a single 16 sec iso 100 exposure will have less noise than 16 1 sec iso 1600 exposures averaged out or added together). Does anyone (read: Daniel) know if this is correct?