Pentacon Six Defect

[Domonkos89]

This lens is relatively easy to repair. Pharmacy soaked in alcohol to clean the blades and will be better than new!

[TheMetroPhotographer]

Could just be lack of lube. Or if it was serviced by a shop recently they may have put the wrong type of lube.

Also, it could be that the linkage that trips the aperature might be binding I've had that happen with my MIR45 lens.

[djamorpheus]

probably oil or dried gunk on the blades which is why they dont close

[NpostEdgeofSanity]

the picture counter spring is just loose its easy to repair ,just did this myself