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Mndean
Tinkerer
Username: Mndean
Post Number: 18
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 19, 2007 - 07:39 pm: | 
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I just got the above lens, and it has an oily and somewhat hesitant diaphragm, so I need to remove and clean it. Anyone have experience with this lens? |
Jon_goodman
Tinkerer
Username: Jon_goodman
Post Number: 9
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 21, 2007 - 06:21 pm: |
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Not the 135, but I have a Celtic wide angle which had the same problem. As I recall I went in through the end and removed the rear and central element and then cleaned the back side of the front (may have been another central element) when finished. Wasn't too difficult.
Jon |
Mndean
Tinkerer
Username: Mndean
Post Number: 20
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 21, 2007 - 10:45 pm: |
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Update:
I went ahead and started taking it apart and found that a) it's a 4/4 lens and b) the rear element and two of the front ones are very easy to remove. In fact, the front element unexpectedly fell out into my hand. What I'm left with is the third element which there seems to be no way to get out without total disassembly. It's s simple lens - the front element is held in by the trim ring only, the second by a grub screw, the rear element is part of a tube assembly that screws in using a spanner. I have access to the blades from the rear, but...
Can I flood the blades with the element still in there and clean it out, or should I just go ahead and disassemble the whole thing? (I lean toward choice #2, I dislike the idea of getting any oil on the lens element) |
Mndean
Tinkerer
Username: Mndean
Post Number: 21
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 22, 2007 - 11:18 pm: |
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Last update:
I went ahead and started going deeper into this lens and found a few things. First, someone had been in here before and was extremely liberal with grease - so much in fact, that it was oozing out everywhere around the helicoid, so cleaning would be a major, major undertaking. It had also sustained some pretty bad damage I saw only after taking the rubber focus ring off, which was why the focus was binding near infinity. I didn't bother splitting the helicoid, since I don't think it's going to get the diaphragm out anyway - it looks to be mounted behind the third element and is there to stay unless I take it down to tiny pieces. I'm much more comfortable with lens assemblies that come out together, leaving the diaphragm in the barrel. I think I'm going to leave this lens to be a donor for other projects. It cost me under ten bucks, and I got a nice set of original (Rokkor!) caps and a circular polarizer in the bargain, so I'm not terribly disappointed. Just a little, but live and learn. |
Mndean
Tinkerer
Username: Mndean
Post Number: 22
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 23, 2007 - 12:38 pm: |
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Very last update -
I went ahead and split the helicoid today and found exactly what I thought I'd see - threads somewhat damaged on the outer helicoid and more gooey black grease than I thought could ever be put in a lens. Splitting the helicoid didn't help remove the diaphragm, either. The diaphragm is attached to the rear of the third element and can't be removed easily. At least I got a lot of small crosshead and grub screws out of this. Maybe I can make something interesting out of the lens elements. |
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