Question on Betax #5 shutter

[Markus Albertz]

A question for those who own convertible lenses mounted in Betax #5 shutters: how does one mount the front element in place of the rear element when using the front element alone? The rear thread of my Betax shutter has a larger diameter than the front, and so the lens elements of my Cooke triple convertible do not seem to be exchangeable. Just wondering if there is some sort of adapter to fit the front element that I don't have. I appreciate that I had asked this question before but never got an answer. Thanks in advance. Best, Markus

 

[jimgalli]

Hi Markus. My 'keeper' XV is also in the 5 Betax. Actually both of the threads front and back are the same in the stock Betax 5 shutter. The lens elements are screwed into bushings that reduce from the Betx threads to the lenses threads. To use the front in the back you need to unscrew the elements along with the bushing. The rear elements also need to come out with their bushing. Now the thread is right for the front group with it's bushing to go into the rear shutter thread. You may need a piece of inner tube or other helper like the ones in the kitchen drawer for jar lids in order to break the bushing loose from the shutter threads.

 

[Curt]

Hi Markus, I have three Betax shutters and the front adapters fit in the back of the shutters. The lens elements stay in the adapters, the barrel they are screwed into. The whole assembly is exchanged from front to back.

Hope this helps,

Curt

 

[Markus Albertz]

Hi Jim and Curt,

Thanks for your replies. Yes, that makes sense to me now. When I remove the front element, the bushing just does not want to come off the shutter. Today, I even put some liquit wrench around the rim very carefully and tried to unscrew the bushing with an old "winter sports" inner tube - no success so far, the thing is just too stubborn. Well, perhaps I just have to live with it. Best, Markus

 

[Markus Albertz]

... I finally managed to remove the bushing from the front of the Betax. Now I can use the Cooke set as supposed to. Thanks again, Markus