I was GIVEN a 1982 CONTAX RTS II Quartz with the 50mm f1.4 Planar lens so I tested it in Brentwood High Street at full aperture. Camera had been banged so frame counter does not work, but lens seems OK.
I found the Contax RTS II Quartz had some 'light leaks' such as the reddish area on THIS photo -- I had already replaced the rotten mirror bumper foam so now i had to take off the door and replace two strips of foam there -- door now fits well and NO light leaks !