View Full Version : Brian, have you ever worked on a Zunow 5 cm f1.1 LTM lens?
Brian, have you ever worked on a Zunow 5 cm f1.1 LTM lens?
Any idea how to get it apart? I see only 3 screws on the lens body, and they are grub screws that hold the iris ring. No other screws visible.
I have no idea how to separate the lens. I've tried untwisting the lens head from the body - it won't budge, even with a lot of force. I know, force is a bad idea.
I've removed the lens name ring - there is nothing under it, and it doesn't even release the front lens.
I'm never seen one in person. It is a rare beast.
We have an RFF member, Mael, that has (or at least had) one.
Try sending him a PM.
I believe I read a post by Steven Gandy on RFF where he said the thing was near impossible to work on. You may want to reconsider your plans and send it to someone. Be careful.
From the other thread: fairly clear that Mael took the lens apart.
The rear group is crimped in place in a brass mount, that has a female helicoid, but this whole rear group is screwed on the lens body without any shims. There is still turns to go. And it is physically impossible to put shims here, because there is no flat surfaces for the shim to stand, nor inside, nor outside. It is the first time in hundreds on lens dismounting I ever see this. I noticed that some resin has been put on the thread. It was very cleanly done, and it was clearly aplied to have the rear group in place at a precise position. Has there was no haze in this rear group, I did not touch anything.
The lens did not have any markings on its body. I purchased this lens with a Kiev IV. The Kiev was approx. registered to the Contax standard, but did not focus properly with this lens. On the other hand, the focus was absolutely perfect on the S3 2000.
Perhaps this lens has been modifyed to be used with Nikons, I don't know ! The lens is now sold, and is making the pleasure of a sympathetic RFF member.;)
Thanks, I've tried sending an email to Mael. No response yet.
Yes, very clear that Mael has had one apart. Don't know which model.
One word: DAG
Vickko, in your previous thread on this lens you asked for recommendations and several of us advised John van Stelten at Focal Point, who are specialists at removing fungus etc. as well as re-coating.
Did he decline working on the Zunow? Not to say that you are considering just anybody, but I've heard Van Steltens praise sung here many times, I truly believe he is the guy you need.
I would love to try out such a lens and compare it to the Nikkor 5cm 1.1.
Mine was a Contax/nikon mount, no helical. It was easy to do, since the lens group was just screwed on the lens mount and locked by just a tiny screw on the side. Sorry for late response, lot of work, Bièvres, etc... !
John van Stelten briefed me on the work required, as well as the internal details of the lens. I don't think I'll be doing the restoration, nor will I have John do the work.
As confirmed, it is a very complex lens to work on. Not a complex design, just a consequence of how it is assembled. i.e. it is assembled as a custom instrument, not one with interchangeable parts, not one with consideration of post-assembly service.
I have taken some photos with it. My impression is that it is less contrasty than other lens in the 50mm range, and perhaps that is a consequence of the lens defect.
have you got any pictures to show us? Very interested!
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