Originally posted by pathdoc Yeah, I came across that on YouTube yesterday; some Canon/Mirrorless-using guy was talking about the interference and in a later video he mentioned the Takumars' rear element also gave him problems on FF Canon bodies. Not all of them, though; he gave me the idea the 28/3.5 wasn't bothersome.
Some pre-Spotmatic Pentax cameras, such as the H3, can not mount some versions of the 50mm, f/1.4 Super Takumar lens, due to the rear element protruding into the body and making contact with the mirror, as it moves.