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Message |
    
Leif
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 15, 2006 - 01:04 pm: | 
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I intend to clean and check for fungus the above lens. Removing lens cells with an indent on opposite sides should not be too hard. But the front of the lens has a cover (with filter thread) that shields the first lens cell. How do I remove the cover? I suspect that it might be screwed in place, but getting a grip on it to turn it looks tough, especially given the build in lens hood that prevents access to the edge.
Here is a picture of the front of the lens:
http://www.photozone.de/upload/917.jpg
Please not that I would like to leave no trace of my having removed the cover.
I have thought about using some calipers and rubber pads to grip the cover on the inside of the filter thread, and turn it that way.
Thanks, Leif |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 16, 2006 - 06:11 am: |
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Hi Leif:
I don't know, I've never worked on this lens.... but I have a hunch that the ID ring unscrews. Get a piece of plastic drain pipe, of a size to match the front ID ring of the lens, and cover the edge of the pipe with double-sided foam adhesive tape; then press this firmly against the front of the lens and twist counterclockwise and see if it comes off. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 16, 2006 - 10:12 am: |
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I have never handled this optic, but would add the following caution to Rick's very sensible hunch. If the built in lens hood has a rubber grip ring at its base, it is possible that the ring conceals access holes for grub screws that lock the ID ring in place. The ID ring is obviously the hood retainer as well as filter mount. Even if no rubber ring, the disassembly instructions may have you removing the whole front section so that hood goes rearwards - revealing grub screws. If the ID ring seems reluctant to move do not force it, Look for one or more lock screws.
As I said I have no knowledge of this Nikon optic, my observations are based on stripping Canon optics with with hood retainers etc. |
Leif
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 17, 2006 - 10:11 am: |
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Rick/Glenn: Thanks for the useful suggestions. I will give it a go. There is one small grub screw on the barrel revealed when extending the hood. I am reluctant to try it as it is all too easy to strip the head. Hopefully the end cap and filter holder screws off.
Leif |
P Laskey
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 17, 2006 - 03:23 pm: |
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There may be more than one grub screw. I have the standard 200mm with hood, this has one hole in it but there are three or four grub screws accessed by turning the hood so the screws can be got at through the hole. If you can find one screw - which takes a while - there will be others in line with it.
PL |
Leif
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 25, 2006 - 12:27 pm: |
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Thanks PL.
Extending the hood reveals a tiny screw on the front barrel. I decided to remove the screw. I then unscrewed the front barrel, which moved it forwards about 7mm. But once unscrewed, it would not pull off, and just rotates freely. On the inner barrel I can see two partially obscured largish cross head screws (not accessible to me) and a hole with what looks like some glass visible. Any ideas?
This could take some time ...
Leif |
