Conclusion: I bought this lens for use on my 1ds. After taking a few test shots and inspecting them I was dismayed to see the amount of CA around the edges, almost like looking at a 3D movie without the glasses on! I returned the lens the following day.
Pros: Centre of image very sharp. Fisheye distortion!
Cons: Edge of image CA makes lens unusable on 1ds.
Conclusion: I had this lens for only about a month. I like the angle of view, but I could not deal with the distortion on the sides - yeah, yeah, it's supposed to be a "fisheye". I had the fortunate or unfortunate opportunity to play with a Leitz Super-Elmar 15mm rectilinear lens on my 10D - now THAT is what I...