Voigtlander Prominent Lens Disassembly Help!

[Camerakook]

Hi. I just purchased a nice Voigtlander Prominent outfit complete with 3 lenses and many other accessories. The downside is that it stored properly and all three lenses have internal fungus. I want to clean the internal elements but I am having a hard time disassembling the lenses. Lenses are: Nokton 50mm f/1.5, Dynaron 100mm f/4.5 and Skoparon 35mm f/3.5. I started with the Nokton; I removed the front info/retaining ring, but the front element will not come out; I don’t see any other retaining rings. I removed the three screws and ring on the rear mount and can not figure out how to proceed. I can’t find any information online and need some advice. Does anyone have experience with the lenses? Thanks!

 

[Sonnar Brian]

It has been many years since I took the Nokton apart. The front section unscrews. Look to see if the front elements unscrew from behind, as they do on the Summarit.

 

[Camerakook]

Thank you for the info. I was able to unscrew the front lens group and get to the fungus. Of course I lost the small ball bearing that provides the clicks for the f-stops. Such is life! I’ll have to search for one now.

 

[oldhaven]

I have a Prominent Nokton with almost perfect glass and function that came with a Voigtlander Prominent 1. I can use it as is but it has quite a bit of oil on the aperture blades. The aperture works and sets the correct opening, but I can tell it is a bit draggy when I use the aperture ring. From the above conversation I can understand that the front end of the lens unscrews, and that I need to watch out for the ball and spring underneath. My questions are whether the front section contains all four elements ahead of the blades so that the aperture blades are exposed for cleaning, and whether I need to remove the beauty ring or anything else before I unscrew the front section. Thanks,
Ron
Edit: would it be easier to access the aperture blades from the rear by removing the rear lens block? It doesn't seem big enough to contain the three elements on that side of the aperture blades.



Further edit: This diagram seems to show that removing nthe rear lens block will enable access to the blades, and perhaps they can be carefully cleaned in the tedious method I have used elsewhere with a Ronsonol moistened bit of lens tissue and patience, but if anyone has experience here, I would appreciate advice before I jump in.

 

[oldhaven]

To follow up, I removed the rear lens block and the aperture blades were easily accessible and very oily. After an hour of careful use of Ronsonol dampened cotton swabs and working the mechanism they were clean again. Opening and closing the blades while the fluid was on them brought the oil on the front of the blades to the back so both sides were cleaned without having to open up the front of the lens. The blades close now easily and stay flat. Before they would spring into a slightly convex shape then snap flat when being closed due to the drag of the oil. Not having a helicoid makes this lens pretty simple.