Originally posted by dedmozaj I looked at the stop-down coupler through the back door with shutter open. If I set the lens to f 22 before mounting it, the meter does give readings on on all stops when I go from f22 to f1.7, but once I start closing it back toward f22, the reading stops at f4 like I have already described. I can actually see this through the back, with shutter open. If lense mounted with f22 set, the coupler starts at very top. When opening, it moves all the way down, but when closing, stops at f4 and does not move until opened above f4 again.
What exactly is broken here?
That's probaly just a spring, that forces the coupler back into its starting position against the force of the lens' lever. May the spring is just aged or broken. Well, at leats that would explain such a behaviour. I don't think it is more serious.
Ben