Out there in the web, there is little information about the performance of the different Canon FD 35mm lenses and that is of varying quality. Since I was wondering, which of the nFD versions is optically the best I ran an extensive comparison and compared them in the most relevant categories.
The Voigtländer 12mm 5.6 Ultra Wide Heliar is actually one of the lenses I bought a camera from the A7 series for in the first place. It is worth to mention though, I am reviewing the old M39 version here. The newer Leica M version is optically the same, although there are other differences – apart from the lens mount – which I will talk about at the end of this review.