Spyderman
Well-known
I'm posting here in case somebody needs to do something similar. My Nokton 40mm f/1.4 focussing was too loose. Like if all the original grease got pushed away from the helical and there was just too little damping.
I think that many Cosina Voigtlander lenses share the same construction - I think the 35mm f/1.4, 35mm f/2.5 (M mount), 25mm f/4 etc.
The optical block can be removed after loosening a ring from the rear. Focus to MFD to get better access to the notches in the ring. The optical block fits in only one way, there are no problems during reassembly.
The focussing block can be taken apart after removing the 4 screws from the rear of the mount. If you want to fully unscrew the helical, make sure to scribe a mark where the helical threads disengage because there are multiple starts of the thread.
I think that many Cosina Voigtlander lenses share the same construction - I think the 35mm f/1.4, 35mm f/2.5 (M mount), 25mm f/4 etc.
The optical block can be removed after loosening a ring from the rear. Focus to MFD to get better access to the notches in the ring. The optical block fits in only one way, there are no problems during reassembly.
The focussing block can be taken apart after removing the 4 screws from the rear of the mount. If you want to fully unscrew the helical, make sure to scribe a mark where the helical threads disengage because there are multiple starts of the thread.
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Spyderman
Well-known
Ambrosius
Member
Thank you very much. I got an used 40/1.4 and wish to relube it, maybe after one or two months. I have succesfuly relubed some Canon RF lenses like the 35/2, so I suppose it isn´t very different process. Am I right?
Regards
Regards
k__43
Registered Film User
You should write that in bold and all caps.
I ruined a M42 35mm lens once this way, at least that lens wasn't worth more than a good pizza. it was a triple helical couldn't figure out how to get it back together.
Ambrosius
Member
Sure? I relubed some M42 Takumars, Konica Hexanons AR AND recently two Pentax M with great success. Al they have a tri helical, obviously. My worst problem was to unscrew two screws from lens mount on Pentax M 50/1.7. That was really hard work and finally a drill was needed.
Are the screws on Nokton 40 also very tight?
k__43
Registered Film User
well every time I locked it in the lens wasn't focusing to infinity anymore. As I said the lens wasn't worth more than an afternoons work so I've put it all aside. It wasn't even Pentax or CZJ - just a no-name f/2.8.
Ambrosius
Member
I see... It takes practice and the process is sometimes tricky but rewarding.
Yes, I agree. Unfortunately for a first time lens repairer it is not always obvious when components are split just how they interact with all the others involved, or when and where they should be marked for successful re-assembly. I've experienced this myself, more than once. Each time, I've successfully re-assembled the lens involved, but, it can be time consuming, unless careful note is made of where precisely each part is, as it is removed. The last one was a CZJ 80mm Biometar, that took me a few hours to get right again, as the correct helical start ended up being some distance away from where it would have appeared it needed to be. It is spot on, now, but was almost, but not quite, right for an hour or so, and in the end, it had to be moved a number of threads off that second to last attempt, to be right, whereas, the initial discrepancy seemed to suggest only one or two thread starts would have been needed to dial it in--but not so! Experience and perserverance are needed, and sometimes, much of the latter.
Further to the initial observation about marking the helical starts, I'd suggest it may well be helpful, (or even, vital), to mark the precise position of the focusing ring itself, and also note the precise degrees of rotation (540 or 720 deg or whatever) from infinity that the ring is on, at the precise point the helicals part. Starting the helicals together correctly is all very well, but if the focus ring is sitting in the wrong spot at the time, it may still end in tears.
Cheers,
Brett
Ambrosius
Member
Yes. I use to align the focus on infinity before disassembling the helical, and then apply tiny drops of nail lacqer, usually on three surfaces. Red color one is great for that. When I repaired my first Takumar, I didn't make those marks and the rassembling process took me a lot of hours. But hey! I learned the lesson. Now I am even more carefull and take a lot of pictures and measure everything. Relubed muy last lens two weeks ago and it took me just 45 minutes, including infinity check.
My worst problem is, as I said, take apart some tight screws. Need to find a efficient way yet. Sometimes removing old grease takes a lot of time too, is tedious.