A few months ago, I was looking for a fisheye that was not only cheap, but also would fit into the existing port for my camera housing. There really are not that many fisheyes out there to pick from. Looking at lenses based only on whether they were small enough for my needs, I cam across the Russian made Zenitar 16mm 2.8 Fisheye. I was a little hesitant to buy a completely manual (manual focus, manual aperture adjustment) little-know lens built by a Russian company I had never heard of, but it’s dimensions told me it was smaller than other fisheyes, and it was cheap. I scored a used one for under $100, and I’m glad I went with the Zenitar.