replaced by the Olympus OM 50mm f/1.2 MF lens, which is even smaller at an incredible 285g and with a 49mm filter thread, while being improved optically!
may need prolonged UV light to remove yellowing from the radioactive elements used
very soft with ghosting and CA wide open on Micro Four Thirds cameras - see John Foster's test
uses a unique optical design with fourth group of elements is arranged to act as a concave with the cemented surface facing the object. It was specially designed to correct common aberrations of this lens type to ensure images will deliver crisp sharp details.