Those odd Noblex panoramic camera with the lens which swings around give this extreme kind of effect if the lens is pointing up or down, but I don’t see what the point would be taking a panorama with one of these then cropping it, so I’d guess fisheye as well
Edit: I read a bit more here on his site, and he uses square format Hasselblads. I hate to imagine what a Hasselblad fisheye, if such a beast exists, would set you back so I’m plumping for software.