neil_walden Posted July 6, 2007 Share Posted July 6, 2007 Can anyone suggest a remedy or fix for slippage in the lens collar on my70-200mm f/4 lens? For instance, if I compose an image either vertically orhorizontally and lock the collar as tightly as I can, there is lens rotation inthe collar if manual focus is used. Turning the focus ring causes the lens torotate stiffly in the collar and skew my composition. The collar grippedtightly for the first five years or so, but now there is slippage. I've cleanedthe inner portion of the collar and the respective outer surface of the lensbarrel. In inspecting the collar's component parts, nothing seems to benoticeably wobbly or broken. Is there something I can do to restore the grippingpower or do I need to visit a repair shop? Thank you Link to comment Share on other sites More sharing options...
john_hanlon3 Posted July 6, 2007 Share Posted July 6, 2007 Have you tried wrapping the lens barrel with a layer of scotch tape? You could add one layer at a time until you achieve a snug fit. Link to comment Share on other sites More sharing options...
boris_krivoruk3 Posted July 6, 2007 Share Posted July 6, 2007 I folded a piece of paper and inserted it between the lens and collar. It works reasonable well. Link to comment Share on other sites More sharing options...
neil_walden Posted July 6, 2007 Author Share Posted July 6, 2007 Thanks for the responses. Won't adding a scotch tape or paper filler restrict my ability to move the lens from vertical to horizontal format (or vice versa)when I need to do that for compositional purposes? Link to comment Share on other sites More sharing options...
frank_kimble Posted July 6, 2007 Share Posted July 6, 2007 The filler is just there to help lock it down since there seems to be a little excess room. You may have to loosen the locknut a little more to rotate to the other perspective. Link to comment Share on other sites More sharing options...
William Michael Posted July 6, 2007 Share Posted July 6, 2007 >>> Have you tried wrapping the lens barrel with a layer of scotch tape? <<< It is better to line the INSIDE of the collar with tape: very thin felt, with an adhesive back. (like what one would stick on the bottom of an ornament so as not to scratch a polished table on which it sits etc) Lining inside the collar, to achieve a smaller diameter, will put the clutch force onto the lens rather than the other way around. The paper stuck in works too: but lining the collar is a `permanent` fix WW Link to comment Share on other sites More sharing options...
john_hanlon3 Posted July 6, 2007 Share Posted July 6, 2007 "Lining inside the collar, to achieve a smaller diameter, will put the clutch force onto the lens rather than the other way around." I don't understand what this means. The forces on the lens and the collar are equal but opposite. All you are trying to do is fill a gap cause by a few thousandths of an inch wear on the friction sheets on the collar. I would be wary of attaching to the collar something as thick as adhesive backed felt which might prevent proper clamp up and be difficult to remove afterwards. Link to comment Share on other sites More sharing options...
William Michael Posted July 7, 2007 Share Posted July 7, 2007 >>> I don't understand what this means. <<< Yes. After I posted this I re read it (wrong time to do a re read). It was not technically correct, a little short on description, and perhaps could have been taken (by you especially) as curt: which it was not meant to be. I was rushing to leave the office for an appointment and I wanted to enhance what you wrote. I have done this, (not to a Canon lens but the principle is the same). At three or four points (I used three) at equal distances inside the collar attach a thin (about 1mm uncompacted adhesive felt, Note: really thin. You might have to hunt for thin stuff. I understand the clutch is only at three or four points around the diameter, but it worked for me without any slippage the thumb screws on the Canon collars are a good thread, for a strong bind. The `Clutching force onto the lens` comment was referring to the fact that the FELT is clutching onto the lens, not the sticky bit. (i.e. it was not referring to the moments of the forces pre se.) The reason is: It is really easy to apply alcohol or nail polish remover to the collar and remove the sticky later if that is required; but much more caution is required to remove the goo from the lens. I think the collar will be able to be loosened to allow this application, provide the felt is thin. Trust this better explains my original post and my apologies for being less than clear first up. WW Link to comment Share on other sites More sharing options...
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