which brand of adapter hasselblad to mamiya do you have
is there a lot of noise at 800
it's the Mamiya adapter
I'll have to get some iso 800 files posted. compared to iso 800 images from a DSLR (Nikon D3).. then there's more. compared to other medium format backs, it's pretty decent. The noise has more of a 'film grain' look to it.