Zeiss Lens repair tips?

[windhorse]

Hello, I have a very nice modern Zeiss 50mm f/1.4 ZE manual focus lens that I recently obtained for a song because it has a problem that is the focus ring is extremely stiff particularly near infinity but otherwise works perfectly.

Just now I am working in Mexico so I took the lens for repair to an excellent professional camera repair service center in Mexico City and have just finished talking on the phone with the technician who says he has taken the lens apart and found it has two bent parts, probably due to being dropped by the former owner even though it has no cosmetic damage. He says he could fix the lens if he could obtain the two replacement parts but has not been able to do so.

My problem is that he only speaks spanish so he could not explain to me the names of the parts in english that I need to know in order to start searching for the parts in the US or elsewhere.

One of the parts he calls the "barrita" (small bar?); the other he calls the "cuerpo" that he says is an inner component of the lens and I figure he may be referring to the inner barrel. He says he could straighten the "barrita" (small bar?) but this would not solve the focusing problem unless the bent "cuerpo" (inner barrel?) that this bar has to fit into is also replaced.

SO to get to the point what I would like to ask anybody who has experience with taking lenses apart and/or is familiar with the technical terminology and/or has had a similar focusing problem with a lens if you may be able to hazard a guess as to what the names of these two parts may be?

 

[flavio81]

Hello, I have a very nice modern Zeiss 50mm f/1.4 ZE manual focus lens that I recently obtained for a song because it has a problem that is the focus ring is extremely stiff particularly near infinity but otherwise works perfectly.

Just now I am working in Mexico so I took the lens for repair to an excellent professional camera repair service center in Mexico City and have just finished talking on the phone with the technician who says he has taken the lens apart and found it has two bent parts, probably due to being dropped by the former owner even though it has no cosmetic damage. He says he could fix the lens if he could obtain the two replacement parts but has not been able to do so.

My problem is that he only speaks spanish so he could not explain to me the names of the parts in english that I need to know in order to start searching for the parts in the US or elsewhere.

One of the parts he calls the "barrita" (small bar?); the other he calls the "cuerpo" that he says is an inner component of the lens and I figure he may be referring to the inner barrel. He says he could straighten the "barrita" (small bar?) but this would not solve the focusing problem unless the bent "cuerpo" (inner barrel?) that this bar has to fit into is also replaced.

SO to get to the point what I would like to ask anybody who has experience with taking lenses apart and/or is familiar with the technical terminology and/or has had a similar focusing problem with a lens if you may be able to hazard a guess as to what the names of these two parts may be?

"Cuerpo" is simply the "body", in this case he definitely is referring to one of the two main barrels that form the focusing helicoid.

If the focusing ring is stiff due to the lens being dropped then one of those two barrels (most likely the outer barrel) has deformed and this is preventing the focus to work smoothly.

"Barrita" is just "little bar", you will have to let you take a pic to see which bar he's referring to. On the other hand, most (all?) focus helicoids need one or two "little bars", usually brass, that are the ones that prevent the helicoid from turning and thus let the lens slide back and forth. So one of the helicoids are kept from rotating by the "little bar" and slides against the "little bar". Perhaps we can call it "guide pin" or "guide slide"

Google for pics of any lens being dissasembled and you'll find said bar.

 

[windhorse]

Wow, what a pleasure it is to get such a super answer! This is exactly what I wanted to know. Thank you very much

 

[RSalles]

Would be great some pics of those parts, forwarded to the Zeiss factory directly or a rep. in USA.
If the lens has drop, maybe the "cuerpo"/ main barrel has bent, so a lathe work on the old barrel to make it come again would be possible - SK Grimmes in States?

Cheers,

Renato

 

[Sirius Glass]

Welcome to APUG

 

[John Koehrer]

"Cuerpo" is simply the "body", in this case he definitely is referring to one of the two main barrels that form the focusing helicoid.

If the focusing ring is stiff due to the lens being dropped then one of those two barrels (most likely the outer barrel) has deformed and this is preventing the focus to work smoothly.

"Barrita" is just "little bar", you will have to let you take a pic to see which bar he's referring to. On the other hand, most (all?) focus helicoids need one or two "little bars", usually brass, that are the ones that prevent the helicoid from turning and thus let the lens slide back and forth. So one of the helicoids are kept from rotating by the "little bar" and slides against the "little bar". Perhaps we can call it "guide pin" or "guide slide"

Google for pics of any lens being dissasembled and you'll find said bar.

^^^What he said. It's most likely the outer barrel that's bent. The easiest way is with a new barrel but I've
had some success with lapping compound/grinding paste.
To use it the helicals have to be absolutely clean. The paste is put into the helical and you spend some
time rotating the two together. It's not exciting, close your eyes & relax for a bit. Clean the stuff out,
put a bit of grease in it and check it. If it still binds, repeat.
There should be some improvement initially but the paste is pretty fine. Don't expect rapid progress.