The Zenitar 16mm f2.8 is a wide-angle fisheye. On a full frame sensor, it will not get the side edges. This is one of the most known of the zenitar lenses. It is not a 180 degree fisheye, but still not very wide. However, I find that it still distorts less so, or less distractingly than most fisheye lenses.
This lens covers Full Frame, Super 35mm and m4/3 digital sensors. This lens is in EF, matches well enough to the Zuiko lenses, which offer a little more yellow vs. amber tones found in the Zenitar lenses.