FF camera questions: a7Rii vs. D750/810

[mrb]

I've been using a Nikon D810 for photo-modeling for work for the past few years (and before that a D600). I've decided I'd like to replace my Nikon D90 and Sony NEX-5, great as they are, with a new full-frame camera. The D810 gets incredible results due to its ISO performance and high MP count.

I've really like how small and light the mirrorless NEX-5 is, and while I know the A7Rii will be quite a bit heavier, it's nowhere near as cumbersome as the D810. Hefting one of those around 8 hrs per day taking photos nonstop takes a toll on ones arms.

Does anyone have experience comparing the A7Rii and the D810? The new Sonys are supposed to have great ISO and dynamic range performance... I don't really have any existing lenses that would sway me one way or the other, I'd just like to get something that's as good as possible for photo-scanning.

[Arie]

Hi,
while not having used the D800 / Sony A7 II I do have a A7R as well as a Nikon D600. To be frank, I am currently selling off most of my Nikon gear.
As you mentioned, using a bulky DSLR with good lenses such as the Sigma Art 35mm f1.4, can be quite cumbersome when using it all day (though it is a free workout). I personally really love the EVF of the Sony A7R, which is more easy to use than an OVF, since you see what you get, making for example precise focusing much easier. One of the other main reasons for switching is that I can use the A7R airborne as well as terrestrial, the Nikon is just to heavy for that (and I don't need a mirror when using it with my UAV).
Of course, there are some drawbacks to Sonys new Alpha series; since it's a comparatively new system the available lenses are fairly expensive. Sony/ Zeiss has been on a roll releasing wonderful lenses, such as the Batis (25mm, 85mm) the Loxias (21mm, 35mm, 50mm) or Zony lenses such as the small 35mm 2,8 or the incredibly sharp 55mm 1,8.
Furthermore there are hundreds of lenses, which can be adapted, though most adapted wide angle lenses do not work as well as native lenses (corner smearing, color shift).
But of course Nikon can hold its own regarding lenses, Sigma Art, Zeiss Milvius/ Otus are some of the best lenses out there. And one has a wide range of legacy lenses, which can be quite cheap (compared to the other mentioned ones).

Regarding the comparision of ISO, dynamic range and resolution between the D810 and the Sony A7RII, you should just check the usual photographic sites such as dxomark, dpreview etc. to decide if the difference between the two is neglible for you (spoiler alert, the difference between the two is not huuuge!).

At the end of the day, it would seem to me, that choosing one system over another is largely dependend on your personal preferences. Both mentioned cameras are top of the line regarding full-frame image quality. Sony has not quite matured yet (in my opinion) but is on a roll regarding technological innovation.

Cheers!

[stihl]

I read that the Mark 2 a7r has built-in mechanical image stabilisation. I'm not sure if this can be turned off or not but as far as I know image stabilisation ruins it for photogrammetry purposes.

[Arie]

It is possible to deactivate image stabilisation, because this can have an impact on image sharpness when activated using a tripod. Here's a test from Jim Kasson: http://blog.kasson.com/?p=8391

[mrb]

I read that the Mark 2 a7r has built-in mechanical image stabilisation. I'm not sure if this can be turned off or not but as far as I know image stabilisation ruins it for photogrammetry purposes.

Maybe only if you are worried about extreme accuracy... I'm not particularly worried about accuracy down to the sub-centimeter level, but rather worried about being able to take blur/noise-free handheld images in dim light. Should have specified that in the original post.