Great lens. I try to find an opportunity to use whenever I can.
Seems appropriate to use this lens in an aquarium
Most of the time we see absurd fisheye perspectives from the use of this lens, but used properly you can get really great images. There are some impressive examples on this thread.
5DIII, 1DX, 8-15/4L, 16-35/2.8L II, 24-70/2.8L II, 70-200/2.8L II, 70-300/4-5.6L, 200-400/4L 1.4x, 17/4L TS-E, 24/3.5L TS-E II, 35/1.4 (Sigma), 85/1.2L II, 135/2L, 600/4L II