I often find there's some confusion among non-photographers I talk to about what constitutes a fisheye lens. They'll see the curved surface of the wide angle lens that I use for real estate and assume they're seeing a fisheye, but they're wrong. That's still what's called a rectilinear lens, where vertical lines still mostly come out straight. This is a what a real fisheye looks like:
A circular fisheye, to be precise. There are somewhat less extreme angles of view which are still fisheyes, but the principle is all about whether vertical lines are meant to be straight or not. So now you know.
I've rented the lens responsible over the weekend to experiment with, and I've found it certainly opens up a lot of creative possibilities. It's nice to be excited about shooting again, since I'll admit I was starting to struggle a bit to keep coming up with new material for the project. A well-timed boost to creativity, if I do say so myself.
EXIF data:
1/125, f/8, ISO 200
8mm focal length
1/125, f/8, ISO 200
8mm focal length