I've read that on some Canon models ISO settings of 160/320/640 work better in terms of noise than 200/400/800 for some unknown reason. Canon has never acknowledged this phenomenon but many owners seem to be able to see it.
I have conducted a small test with the D800 to see if I could spot sudden changes in noise. Well, I could not. There is a gradual increase in noise at higher settings as is to be expected, nothing else. What do you see?
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