Here is an ISO performance test with the A7R II. I have shot everything in RAW and exported the files as JPG without altering them in any way. They have been shot from ISO 100 to 102400 using the Sony/Zeiss 55mm 1.8 at f13.
The ISO performance is as always at Sony’s high standards. You still have to consider that the sensor’s density has gone up a notch yet again. At high ISOs the images start getting a very fine grain which I know that many photographers like. I must say that I also prefer that to getting that sort of mushiness you can normally see at ISOs.
A7 VS A7R II – ISO PERFORMANCE
Even though the A7R II has a higher MP count, it still wins in ISO performance. The latest A7 iteration generates less color noise, is cleaner and has more detail. And as there’s also a pixel density difference between the 2 sensors, you could always scale it down for seeing an even better performance on the A7R2. The latest Sony sensor has a remarkable efficiency. Also, I noticed this on several occasions, the A7M2 exposes a little brighter than the A7 (but uses a slower shutter speed – probably as it’s counting on IBIS in aperture priority).
Edit: I found out, again and again that the A7R II, compared to the A7, uses 2 thirds of a stop slower shutter speeds. But it seems that the image is indeed brighter, but not 2 thirds. More like 1 third. I think there’s a little bit of cheating going on.