Back in the 80s, I used a Vivitar 2x converter with my MX, with the M200 f4 lens, as well as the K45-125 f4 zoom, and the results were horrible. Very low contrast and not very clear, as if there was a fog filter on the lens.
I either gave it away or sold it and got a T6-2X, which was much, much better. Pat White
