Sony A7s vs A7R
Time for a reshoot. My entire batch of work comparing the Sony A7R to the Sony A7s was wrecked by shutter vibration of the Sony A7R (see in depth review coverage of Sony A7R shutter vibration / shutter shock in my review). At 50mm. I feel really dumb having bothered to shoot the A7R in the danger range, knowing full well what I’ve documented for my readers. A foolish effort, but it drives the point home: the Sony A7R cannot be relied upon for sharp images over a wide range of shutter speeds. By the way, don’t even think about using the A7R for things like focus stacking unless you’re doing very fast or very long exposures. The Sony A7S and A7 offer a vibration-free electronic first curtain shutter (EFC shutter); cameras like the Sony RX1R offer a vibration-free leaf shutter.
The real 36MP workhorse* looks to be the new Nikon D810, with its vibration-free electronic first curtain shutter option (EFC shutter). (Canon has had an EFC option for years with its Mode I or Mode II Live View modes). An EFC shutter is a big deal for long telephoto lenses or high magnification macro work. So while the D800E has served me well as a solid and problem-free workhorse for years (best ever camera in this regard), and I expect the D810 will only make it better.
* The Sony A7R being the workhose.