Zeiss Jena Triotar 4/135mm M42 disassemble problem

[Pancolart]

Hi!

I have superbly preserved Triotar in my hands. Sadly it has very stiff focussing and some inner element seems to have grease (or grease reaction) on glass (it's possible coating damage but i don't want to think that is the case until i am there). I have to open it and clean it.

Please let me know how to do it? It seems impossible. There is only large one screw at the bottom of the lens that seems without purpose. I have smaller bump on the filter thread so i didn't manage to open front plastic yet but i'd like to know if that makes sense at all, since i presume this way only front glass will pop out. On rear side if you'd look into aluminium barrel you could see a way to start the procedure but the barrel doesn't allow approach. I am not newbie in lens repair but i don't have solution on this one.

Any suggestion will be highly appreciated.

BR, Jure

[bawang]

I believe Luis (luisalegria) opened a Triotar once. Let's hope he sees this thread. Or try searching the forum for his post regarding the experience.

Best of luck. I like my Triotar very much. I hope you get to CLA it and enjoy the beauty from this triplet design baby.

KBZ

[Retro]

[luisalegria]

Hi Jure,

Yes, I have a Triotar that was in bad shape.

http://forum.mflenses.com/czj-triotar-135-4-exakta-total-overhaul-t9326,highlight,triotar.html

If yours is like mine, the same methods should work.

To fix the stiff focusing you need to get to the helical to clean and re-lube it. The grease/haze is probably on a surface adjacent to the diaphragm - thats between lenses #2 and #3 counting from the front.

Starting with the back end - There is a tube inside the lens barrel that you can see when you look inside the mount. It goes all the way to the lens head and screws into that, to hold the whole lens together (lens head and mount/helical). You need to unscrew this.

This tube has two slots, meant for a special large lens spanner I think. I used an old key to make a bar that would fit in the slots. I guess you could use anything else that will fit and is strong enough. This can then be turned with pliers, and the tube can be unscrewed normally.

I tried to make a diagram (try Flickr link below), its not very good. If you need pictures I will try to take some when I get home.

http://www.flickr.com/photos/22557486@N02/3082057023/

Unscrew this and the lens comes apart into the lens head with the diaphragm and all the lenses, and the helical/lens mount unit.

The lens head has all the lenses. You need to remove the rear element to get to the diaphragm where the bad surface probably is. This is held on the lens head assembly with the usual slotted ring. You will need a lens spanner to remove that. Once you remove the rear element you should be able to clean the front of lens #3 and the back of lens #2. Its probably one of these thats the problem.

On the helical/mount unit, you should be able to see the screws holding the whole thing together. Unscrew these and the whole thing comes apart, you can unscrew the helical, etc.

As for the front end - the front two elements are in a sealed aluminum cell that you shouldn't need to open, unless thats where the grease or haze is. I don't think thats the problem, so you shouldn't need to unscrew the name ring. But if you do, its a standard technique. You will have to fix the dent first, and then use a rubber lens wrench or other rubber item to unscrew the name ring, there's lots of advice for alternatives all over. If that doesn't work (like with my Triotar, it was just stuck too hard), you will have to drill two holes to insert the points of a lens spanner. The lenses are held in by the usual slotted rings for which you will need a lens spanner.
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I like Pentax DSLR's, Exaktas, M42 bodies of all kinds, strange and cheap Japanese lenses, and am dabbling in medium format/Speed Graphic work.