[toni-a]

ISO 64 is base ISO on a D850 The lowest ISO would be ISO 32


And I doubt very much that you would see a difference of noise between 64 and 100 ISO, but please split any hair you can't see as a full one ^_^

I don't even see a house difference between ISO 100and 200 however if you need to add +2 or 3 f stops then difference is relevant

I would have loved to have ISO 64

Kodak SLR had the lowest ISO of an SLR made, 12 or 6 I think, too bad manufacturers are only occupied with clean high ISO leaving the job to ND filters