Secondly, and perhaps, most unexpectedly: the camera's phase-detection autofocus capabilities have been increased to the point that it not only focuses quickly and effectively with its own lenses but can also do so with lenses designed for other systems.
These two modes should let you choose between the shallow depth-of-field and low-light capability of using the full sensor, vs.You can record in 4K and scale down to UHD without loss of aspect ratio or distortion.You can not record in UHD and upscale to 4K without creating distortion.I'm using the A7R ll with the sony zeiss FE F1.8 55mm and tripod and getting inconsistent sharpness. I focus manually ,shoot raw, and steady shot is on. Now more than a year after buying it, I couldn't be happier with my A7r II.The overall combination of the 42mp bsi sensor, a great autofocus system, absolutley necessary IBIS, and some really high quality lenses, just consistently delivers a level of image quality that is totally rewarding.
Like the recently-released, and more video-focused a7S II, the a7R II can record 4K (UHD) video internally.