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_nathan
Tinkerer
Username: _nathan
Post Number: 6
Registered: 04-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 14, 2008 - 11:23 am: | 
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Hello. A lot of the telephoto Zoom-Nikkors suffer from 'zoom-creep,' meaning that they will zoom under their own weight if the camera is tilted towards the ground. Does anyone know if this is easy to remedy, or would it require a complete tear down, and subsequent relubrication of the lens? Thank you in advance for any insight. |
M_currie
Tinkerer
Username: M_currie
Post Number: 128
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, May 15, 2008 - 11:50 pm: |
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I have not investigated too far, but I've been told it's not easy to fix, which is why so many are like that still. I'm not sure it's a lubrication issue. Again, only relying on what someone told me, I have heard it has to do with a felt ring or something of the sort inside, which wears. It's too bad because it's an annoying problem, especially when attempting macro work. Sometimes a piece of tape placed under the sliding part of the zoom can help, but it's annoying to have to apply a home-made workaround to what ought to be a better design. |
Ethostech
Tinkerer
Username: Ethostech
Post Number: 95
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 16, 2008 - 02:53 am: |
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Unless the unit has been opened up and either broken or incompetently serviced - your description typifies dried out lube of the helix. It is reasonably easily fixed by regreasing the helix with a grease of suitable viscosity. "Reasonably" - because zoom lenses can sometimes be a pain to service. If nobody has been there before you - it should be straight-forward. |
Glenn
Tinkerer
Username: Glenn
Post Number: 350
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 16, 2008 - 10:32 am: |
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Not familiar with the construction of these lenses. On some lenses it is possible to push a ring of self adhesive felt, between the zoom ring and the barrel. If the correct thickness of felt is used, the added friction brakes the zoom ring - thus holding the zoom action. I have done this on a number of zooms with good results, however none were manufactured by Nikon. If M. C's informant is correct, it will be difficult to get a nice feel to the zoom action, by regreasing alone - the felt seals will also need replacing. Hence the value of the labour saving dodge.
I used the self adhesive felt supplied by Jon Goodman - Just cut a strip about 1/4" wide to go around the circumference. If you lick the adhesive side well, you will find that you can easily push the felt strip into the gap. On some lenses, small pieces placed at 12, 3, 6, 9 o'clock work just as well. Make sure you position zoom ring/barrel in correct relationship to each other, so that the felt remains fully concealed during the complete zoom cycle.
To test if the above will work - place a suitable thickness of card under the zoom ring, to stiffen up the action. If this stops the 'creep', proceed as above. |
M_currie
Tinkerer
Username: M_currie
Post Number: 129
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 17, 2008 - 09:12 pm: |
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Responding to Ethostech, I should mention that I'm talking about "one-touch" zooms, such as the 35-105 AIS, a notorious creeper. I don't think there's a lubricated helix on the zoom portion of these. |
Glenn
Tinkerer
Username: Glenn
Post Number: 352
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 18, 2008 - 03:20 pm: |
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Obviously the construction of one touch zooms will not allow the above quick fix to be used. In all the one touch lenses I have worked on, there has been a rubber or plastic 'damper' on the holder of the zoom group. In most cases the insert had 'worn'/'hardened' and thus did not brake the holder. Unfortunately; on many lenses there is no built in adjustment on the friction damper, thus you have to replace/remanufacture the insert. Many one touch lenses seem to use a couple of spiral slots to move the zoom group, rather than a multi-start helix. Whilst there may be a wipe of grease on the slots, many lenses seem to use plastic followers, thus negating the need for lubricants. |
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