You're correct. What I'm wondering is why they used a 1DX instead of a Sony A7S? The ISO range on the Sony would of probably outdone both Canon and the Mamiya.
Taking photos at ISO 409,600 would be pretty awesome IMO.
Taking photos at ISO 409,600 would be pretty awesome IMO.
If you can do that already with the sensitivity you've brought, higher ISO doesn't buy you anything...
Why not use the Sony A7S? The photographer uses a Canon 200-400mm f/4 lens, and the nearest Sony equivalent is 70-400mm f/4-5.6, which means at the long end it captures only half as much light, instantly negating any possible ISO range advantage offered by the A7S.