can anyone speak to the non-obvious (like more megapixel) advantages of shooting this on the medium format Mamiya that he mentions? I've always been intrigued by MF cameras, but they cost so much more causing them to be inaccessible (to me anyway).
My understanding is: 1) More megapixels, 2) a larger sensor (more than twice as large) means more signal-to-noise at each pixel site which means less noise in low light, 3) the Mamiya has far greater dynamic range (around one stop greater, double the amount of light).
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.
You don't really want photos at ISO 409600 per se, though, you just want photos at the lowest ISO that can get you the necessary depth-of-field for your shot (here extended with tilt-shift lens) at whatever shutter speed avoids being too shaky. And then you want as high of a dynamic range of possible, so you can distinguish the brightest brights from the darkest darks in a single shot.
If you can do that already with the sensitivity you've brought, higher ISO doesn't buy you anything...
Why use the Canon 1DX? The photographer has a long-standing and public relationship with Canon.
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.
Old-school medium-format film cameras are reasonably accessible -- you can get a Mayima 6x7 and a meh-okay lens for around $400, and even with a damned good lens can find lots of stuff in the sub-$2000 range. It's the digital medium-format rigs that break into five-figure territory -- and it takes a good little amount of film / processing costs to make up for that expense for the hobbyist.
Myself, I'm using my grandfather's old Canon 50mm/f1.4 on a Canon Model 7 rangefinder (essentially the last battery-free Canon) for film and the same lens on a (used) Leica M8 for digital. Nice fast lens, but still in 35mm-land.
It's an overall larger system. A larger sensor means less noise (assuming fewer pixels per inch, which is true in this case). A larger lens means less distortion (because any imperfections are smaller relative to the entire glass).
And it's very expensive, which means even a relatively small advantage in image quality will make the resulting pictures more valuable, at least for a few years until someone else does this again with newer technology. DSLR photographs are truly commoditized now, but medium format are not, never have been, and probably never will be.
