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CJ
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 13, 2006 - 04:24 pm: | 
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Hi All,
I have a Nikkor 50mm f/1.4 given to me by a good friend who no longer shoots film. The lens has a small amount of particles/fungus inside, and while it's not terrible, I'm wondering if an average Joe like me can disassemble and clean the elements.
I've cleaned the fungus off the inside front of a 80-200mm Kalimar, but it was just the frontmost element, and the lens itself was a $6 impulse buy. I'm not sure I'm confident enough to try the same (and more) with my fastest lens, which I cherish.
Also--part of the reason for this query is that I vaguely recall reading Rick's mentioning some sort of 'alignment' issue re: reassembling lenses. Can anybody clarify this? Or did I just misunderstand something?
-CJ |
Ed
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 15, 2006 - 02:21 pm: |
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Can you tell, by looking, if the fungus is on the inside of the front or rear element. There is a front element group and a rear element group--if the fungus is on the inside of either of these, as opposed to between the elements, it is a much easier job. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 15, 2006 - 05:02 pm: |
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The easiest way to 'see' where the fungus/damage is located is to use a stereo microscope. You are thus able to focus not only on the fungus, but the individual element surfaces.
Starting on the front surface you can focus down through the lens. If you do this slowly, you can easily detect each glass/air interface and thus where the fungus is located.
With the right set up it is possible to do this with a set of macro bellows and a slr - well I can use my two Canon Photo Macro Lenses ( 20mm and 35mm) and get the same results as my stereo Wild. |
CJ
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 15, 2006 - 05:13 pm: |
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Ed and Glenn--
The particles of fungi that I noticed appear to be on the second element from the front. I didn't see any bad stuff on the rear elements when viewed from the rear element.
So my hypothesis is to disassemble from the objective element inwards, cleaning as I go. Regarding reassembly: are there any alignment factors, or anything else I should be aware of?
-CJ |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 15, 2006 - 06:06 pm: |
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CJ,
Sorry I cannot give you any information on the Nikkor range of lenses, I was a young recruit to the Canon fold. However I have not come across any specific alignment issues on the various makes of 'standard' lenses that I have worked on. What has been noted in the various repair manuals, is the fact that some lens groups are matched on assembly. You therefore cannot just replace one scratched element - the whole cell/group must be replaced with another matched set. As you are not doing this I do not think you will have a problem, just look out for shims sitting in the recess. I have missed the odd one before now, it fell out as I cleaned the interior of the barrel. Fortunately in my case it would only fit in one location.
Glenn. |
rick
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 15, 2006 - 08:20 pm: |
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does this help?:
http://rick_oleson.tripod.com/index-102.html
most Nikkors are built similarly: you can pull the entire lens out of the focusing mount in one piece, and then remove the front and/or rear cell from the barrel. This will expose the center element surfaces that face the diaphragm; to get to any other surfaces you will have to remove individual elements from the cells.
apart from making sure the little linkage thingies are lined up correctly, reassembly into the outer shell is prety much a matter of dropping the lens back in and reattaching the front ring. |
CJ
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 15, 2006 - 10:42 pm: |
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Rick,
Awesome. Thank you for creating that diagram!
And Glenn, thank you for your advice. I'm glad you noted that certain lenses have matched elements: That'll probably save me (and anyone searching the forum posts in the future) a lot of grief at some point.
-CJ |
