The name is suitable for this kind of lens because you achieve incredibly width – almost a round view (the lens is a little bit convex like a fisheye – I don’t know why it is called like that). The fisheye lens is a special-lens, you should work with that careful because the effect wear off if you are using the fisheye to many times it will be plain vanilla.
In the right moment you can create with this lens amazing pictures (hold it over your head while you are in a crowd and shoot down (if your camera has a moving screen – you should see what you are shooting)). Fisheye lenses are deforming horizon line in the picture. You will get the minimum deforming while you are holding the lens near to the body.
I take this kind of lens if I’m taking pictures of…
…a crowd, while I am in a stadium or skyscrapers.