Using the Sonnar T* FE 55mm F1.8 ZA on both cameras at f/5.6 I shot the same image at ISO 100, 640 and 3200. See below** for links.
At ISO 100 the advantages of the higher pixel count and the lack of an AA filter show up. There is more detail in the A7r shot. Though it has to be said, not by much and nothing that a bit of post production sharpening couldn't sort out.
At ISO 640 both cameras still turn in an excellent performance, producing very clean files. Once again the A7r produces slightly sharper results.
At ISO 3200 the A7R starts to show some noticeable noise, though still producing a sharper image. The A7 II is still very clean.
All of the above are from OOC jpgs. but I got very similar results identically processing the raw files. Obviously shooting from raw you can add sharpness to the A7 II files or choose to use noise reduction of choice on the A7R.
So, this is pretty much in line with the results from the original A7. The A7R is the ultimate camera for resolution. It has those extra pixels and produces a larger file. If you are not that bothered about the higher ISO settings and the IBIS of the newer camera isn't important, then the A7R is really the mirrorless camera to beat for ultimate image quality. The Nikon 810 is apparently marginally better and we have to see what the Canon 50MP 5D offers, but the A7R is still a terrific camera producing quite amazing images.
The A7 II is however a great all round camera. One of the best ever made. It can handle a wide range of photographic situations and produce top quality files. The IBIS, AA filter and higher pixel density all contribute to it being a better option in low(er) light. Not as good as the A7s, but that camera achieves it's phenomenal high ISO performance from a 12MP sensor. The A7 II is the best option if you want files for large scale reproduction and you don't spend all of your time photographing black cats down mineshafts. But that A7R is still a pretty special camera.
A7 MK II Files
Please note:- Above files are for personal appraisal only. Reposting and sharing without permission and a link is not permitted.