Ever since I got to play with one back in the 1980s (using it on my Zenit 11), I've wanted a fisheye lens of my own. Trouble is, they're generally expensive, especially given the limited use they have.
And then, a couple or so weeks back, while browsing for something else on Amazon, I stumbled on the Opteka 0.20x Fisheye Conversion Lens:
It turned up yesterday and, last night, just as the sun was setting, I managed a very quick walk around the village to give it a quick try:
Opteka 0.20x Fisheye Test
My initial reaction is very favourable. There's very obvious fringing as you move away from the middle of the image (which I expected), but the sweet spot is very sharp and, overall, it's nice and easy to use.
Great little toy that will get more use.