[Rover]

I don't question the utility, nor the fun factor, of a diagonal fisheye, especially not since one had appeared in my household (and you can see many of these pictures in my Instagram). It's the circular variety that makes me wonder (at least for non-specialised use), though the 4/3 format probably makes life easier for it because it's "taller" and the circle of the useful image is larger in the frame.