Olympus C-180 is an old "teleconverter" from back in 2000. By accident I found one, and tried it with a step up adapter on the Oly 1,8. And the combo seems to be very sharp. In fact it become a 76,5 1,8! It is much cheaper and lighter than the 75 1,8. Not very sexy, but it works. Believe me or not. The converter is to be found on ebay, very cheap. And the stepdown ring 52-37mm is allmost for free.