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View Full Version : Stiff ZD 50-200mm zoom


HughofBardfield
30th June 2008, 01:18 PM
I have an old style ZD 50-200mm which has recently developed an excessively stiff zoom action. Zooming in is fine, but zooming out back to the 50mm end requires real effort - so much that I'm concerned about the strain on the lens mount.

Has anyone else experienced a similar problem and effected a cure? I'm trying to avoid a trip to the lens doctor for cash flow reasons!

Chillimonster
30th June 2008, 02:06 PM
Has it suddenly become 'stiff' or has it always been like that?

I have hold of various 50-200mm's, both old and new. Some were loose, some were too loose (for me anyway) and some were too stiff.

But if it has suddenly started to become stiff, it could mean it needs that visit to the lens doctor :(

Chris

andym
30th June 2008, 02:07 PM
Hugh

I have herd of this happening when there is a problem with one of the two rubber sealing rings that go round the inner barrell.
Dont want to be the bringer of bad tidings but I think it will need to go to service.

Jim Ford
30th June 2008, 02:12 PM
I wonder if the weather seal is causing the binding? This would explain why it binds only with the lens zooming back in. If the rubber is dragging on the lens barrel it would tend to release its grip zooming out, but tighten zooming in.

I would use the _tiniest_ trace of silicone grease on the barrel - not even enough to leave a visible smear - to avoid picking up dirt. Maybe silicone furniture polish would be as good or even better. Again, you should only use the faintest trace.

Jim

HughofBardfield
30th June 2008, 06:40 PM
Oh dear! Thanks for the comments. I suspected the weather seal as well.

I bought it last Summer on eBay and it has been fine until fairly recently, but it sounds like the Doctor is required... I don't fancy greasing something myself in case there's a more serious misalignment underlying the stiffness.

Colchester Camera Repair Service is my nearest centre AFAIK - anyone have experience of their work?

Jim Ford
30th June 2008, 09:50 PM
I don't fancy greasing something myself in case there's a more serious misalignment underlying the stiffness.

What I suggested is not 'greasing' as such. The amount I'd use would be scarcely larger than a pinhead - just enough to leave the faintest trace on the barrel.

Jim

HughofBardfield
1st July 2008, 10:03 AM
What I suggested is not 'greasing' as such. The amount I'd use would be scarcely larger than a pinhead - just enough to leave the faintest trace on the barrel.

Jim

Sorry Jim - I know that's what you suggested: I didn't mean to imply you'd advised applying axle grease with a spatula! :D

I'm just wary of applying even a minute trace of something myself in case it seeps in somewhere it shouldn't.

HughofBardfield
14th August 2008, 05:52 PM
What I suggested is not 'greasing' as such. The amount I'd use would be scarcely larger than a pinhead - just enough to leave the faintest trace on the barrel.

Jim

Finally, finally plucked up the courage to try this after getting rained on at the London Triathlon on Saturday. :eek: The stiffness had come and gone, and hadn't been bad enough to ship the lens off to Oly, but came back again after getting (only mildly) damp. I also found I had some silicone spray lubricant specifically for 'o' ring seals that I'd forgotten I had (don't ask).

Tried just the very faintest trace sprayed onto a lint free cloth and wiped around the inner lens barrel. Result - transformation (so far, at least).

I bought the lens used and it was... well, filthy when it arrived. Obviously I cleaned it up thoroughly, and may have inadvertently removed the factory lubrication, or it may have simply come away with the dust I removed from the crevices!

Either way, thanks for the suggestion Jim. All being well, you've saved me an expensive service! *chr

Chillimonster
14th August 2008, 05:58 PM
Excellent result :)