Broadly speaking there are two kinds of fisheye: those that produce a circular image surrounded by black, and those that give more image, but less field of view. The Nikon 10.5mm f/2.8 lens used here is a DX lens, so designed for crop-sensor cameras. Nikon’s 16mm fisheye may be a better option if you use a full frame camera. A good fisheye doesn’t come cheap, so it might be one to rent or borrow before you buy. If you’re on a tighter budget, there are also good third-party options, like the Sigma 10mm and Samyang 8mm.