Hi everyone. I have a 50 mm 1.4 lens breech mount that won't go past f4 when mounted. From f1.4-4 I can see the aperture narrowing but after that it won't narrow down further. When I dismount the lens and disengage the lock pin it does fully go through 1.4-16 with no problem whatsoever. Any thoughts? Can anyone point me in the right direction?