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Rick11949
Tinkerer
Username: Rick11949
Post Number: 16
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 26, 2008 - 04:04 pm: | 
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Hi,
I had a 135mm f2 AIS Nikkor replaired by Nikon over a year ago, when they returned it to me I noticed the focus was very tight. I should of returned it, but foolishly I thought it would loosen up in time. It has not. It is very tight but uniform and not binding. Is there anything simple I can do other than giving it back to Nikon? |
Glenn
Tinkerer
Username: Glenn
Post Number: 328
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 27, 2008 - 03:53 pm: |
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Nothing simple will solve this, so I would send it back. However make sure the lens is 'actually stiff', and your comparison lenses are not 'loose'. Nikon may have lubed the helical as per specification, and the lens may be OK as far as they are concerned. On the other hand, they may have used a grease specified for later optics - hence your problem. There is much more clearance in many autofocus helicals, hence a heavier grease can be specified. |
Rick11949
Tinkerer
Username: Rick11949
Post Number: 17
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 27, 2008 - 10:06 pm: |
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Glenn,
I found the repair receipt, it was a class "C" overhaul and they replaced the helical assembly, so it's new and greased to specification (I assume). I own over 20 MF Nikkors and they all feel smoother (some too loose), but all were purchased second hand so I can't say what a new one would of felt like. I'm going to try working it free by focusing it back and forth a few hundred times while watching TV. If that fails I'll take a drive to Nikon (40 miles away) and have them evaluate it. Thanks for your reply.
Rick |
Glenn
Tinkerer
Username: Glenn
Post Number: 329
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 28, 2008 - 05:42 am: |
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Rick,
Your 'working' the focus could smooth things up as the two surfaces wear in. However this will not necessarily 'free up' the actual tightness you experience. I fully appreciate your feelings, as I like to have a unified feeling to the focus on all my lenses. As I have stated on one of the grease threads, this gets difficult as the diameter of the helical increases. If I grease my Jena f2.8/180 with some of the recommended products, I can hardly move the focus!!
As you say, the lens should be to spec, but I have had odd things happen when replacing worn items with 'factory fresh' parts. At least your Nikon repair shop is not too far away! |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 564
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 28, 2008 - 05:04 pm: |
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Nikon lenses seem to get extremely loose in focus in their old age, and while it's been some time since I've handled a brand new one I'm sure that a fresh Nikkor must feel much tighter than most of mine do. This is not to say that there isn't a problem with your lens of course |
Rick11949
Tinkerer
Username: Rick11949
Post Number: 18
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, April 28, 2008 - 09:56 pm: |
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Thanks guys. Now comes the dumb question...will keeping the lens in a warm enviroment (controlled ~ 90-100f) thin out the grease, or will I only make things worse? My hands are getting tired. :-)
Rick |
Glenn
Tinkerer
Username: Glenn
Post Number: 332
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 29, 2008 - 06:47 am: |
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No, the grease should be stable over that temperature range, so heating it up will do nothing to help matters. If it's not stable, you may get a bloody mess inside the lens! Taking on board Rick's practical experience, I would take that 40 mile trip and get a second opinion. |
Rick11949
Tinkerer
Username: Rick11949
Post Number: 19
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 29, 2008 - 09:32 pm: |
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Glen,
Thank you. The next time I'm traveling in Nikon's direction I will drop in and ask if a tech can have a quick look at it.
Rick |
