Prontor Pro Shutter Release Cable Repair

[Pertho]

Hello everyone,

I recently acquired a new-to-me lens in a Prontor Pro shutter, complete with a 3 stage mechanical shutter release cable. The shutter seems to be in great condition, but the release cable isn't operating properly: It's intended to be able to move the shutter through 3 stages: fully closed, shutter open with aperture at current setting, or shutter and aperture fully open. Currently, when you move the selector into the 'shutter open, aperture stopped down' option, nothing happens. And when you go into the third 'shutter and aperture fully open' setting, it actually only opens the shutter, and doesn't open the aperture.

Essentially, the throw of the cable release isn't long enough. I've confirmed this using a standard cable release, which can move the shutter through all those modes with ease; and by taking the back panel off of the release cable to observe the mechanism in use. I'm fairly mechanically inclined and would love to give fixing this mechanism a go, and I have some thoughts on how to go about it - but it would be fantastic to see a fully working one, to confirm or correct my assumptions. If anyone would be willing to share pictures of the inner workings of a functional one, I'd be deeply grateful. A picture of mine can be found here for reference, and it is marked "Made in West Germany", which may help to date it, somewhat.




Thanks for reading!

[cowanw]

? need two cables
https://skgrimes.com/wp-content/uplo...onspiel800.jpg

[Pertho]

? need two cables
https://skgrimes.com/wp-content/uplo...onspiel800.jpg

Yes, you use a second cable release to fire the shutter. That isn't what I'm talking about though. The internal mechanism within the cable release I have pictured that is used to hold the shutter and aperture open while you compose an image on the ground glass isn't working properly (as outlined above). You can use any cable release with a locking mechanism to do the job, but I am curious about repairing this one as a pet project.

Thanks for your input though!

[Greg]

Essentially, the throw of the cable release isn't long enough.

Sinar OEM cable releases that were used with the Sinar Copal shutter, I believe have the longest throw of any cable releases. Unfortunately they are quite hard to come by without also purchasing the shutter, but they do come up for auction every now and then. I once did have a jeweler craftsperson "micro weld"? a short extension to the end of a cable release for me. Unfortunately I went back to him a second time and found out that he retired.
I believe that Gitzo once offered a cable release with a long throw, but I have never seen one come up FS. Maybe someone could confirm this?