Old Minolta lens fault...

[woof woof]

Has anyone seen this before...

I have an old Rokkor 50mm and the aperture blades are nice and snappy at minimum focus distance but as you move towards infinity there's a change at about 1.75 ft and the blades begin to hesitate from then on to infinity. It happens whatever direction you go in, from min to infinity or infinity to min and it happens at all aperture settings.

Is there a connection somehow between the focus distance and the aperture blades? Looks like there is...

Just wondered if anyone had seen this before.

 

[HoppyUK]

With older lenses like that, ie non-internal focusing, the whole optical assembly moves back and forth. Therefore, I'm guessing, it will have to slide along the aperture actuating arm and presumably something is catching at some point, or maybe bent?

If it was me, and it was a real problem, I'd pull it apart and have a look. Depends how mechanically inclined you are, but there's nothing but sweet quality engineering inside. Strangely enough, I have a 50mm Rokkor here and I'd start at the back with all those little cross-head bolts. But don't blame me!

 

[woof woof]

I've not had it 5 minutes so it'll be going back whence it came.
Glad to know I'm not going mad though.