For when you just can’t get enough resolution.
At 61 megapixel, this is quite impressive, especially if you wish to have really large prints, or aggressively crop. As this is the R(esolution) model, don’t expect top of the line 4k60 10bit video. While it can do 4k30 8bit, this is strictly aimed at high resolution.
There are a million reviews out there, so I won’t go into it, other than to say this is a great camera to get, especially since the a7R V was just announced yesterday.