hilbert5 Posted March 24, 2007 Share Posted March 24, 2007 Hi all, to be open I guess I have read here a kind of instruction quite some time agobut I cannot find it anymore. Maybe someone can provide the link or give me someadvice. This is my problem:I own an FDn 35mm f2.0; the focus ring is a little loose. When focussing, I canjuggle it about 2mm before the focus really changes. The juggling is only in thedirection of its normal turning. This problem is not new and I did not care toomuch so far. But very often I have taken pictures in low light recently, and nowthis little juggling gets on my nerves when it comes to exact focussing. Hope someone of you specialists knows how to solve this problem. Cheers+Thanks,Ernst. Link to comment Share on other sites More sharing options...
awahlster Posted March 24, 2007 Share Posted March 24, 2007 Most likely the little screws that hold the barrel to the lens elements has come loose. You might try carefully pulling back on the rubber grip to see if there are screws underneath. If so line up the distance scale best you can and with a proper tiny screw driver tighten the screws keeping in mind they are tiny and to not over tighten them. Link to comment Share on other sites More sharing options...
hilbert5 Posted March 24, 2007 Author Share Posted March 24, 2007 Hi Mark, thanks for your quick answer! It there a trick to most "carefully pulling back" the rubber ring? (I am thinking something like warming it with a hair dryer): Cheers,Volker, Link to comment Share on other sites More sharing options...
hilbert5 Posted March 24, 2007 Author Share Posted March 24, 2007 Sorry. But Volker is one of my nick names in other forums. Read it as Ernst. Link to comment Share on other sites More sharing options...
alan_swartz Posted March 24, 2007 Share Posted March 24, 2007 Ernst, There is a pin, screwed inside the focusing ring, which engages a fork inside the lens, thereby coupling the ring to the focusing helicoid but allowing the helicoid to extend and retract while focusing--the pin slides in the fork. The pin once had a plastic bushing around it, which has now probably disintegrated. I have a lens with this problem. The pin is therefore too small in diameter to fit closely in the fork, so you get some rotational play. It is annoying, but it does not affect the actual focusing at all, only the feel of the ring and of course the indication on the focusing scale. It does not disturb the relationship of the lens elements. You won't need to heat the focusing grip. Use a somewhat sharp wooden or plastic object, work it under the edge of the rubber grip, and gently begin lifting and working around the ring. The grip will stretch enough to come off. It is held in place with a slightly tacky adhesive, which you will have to break loose. Do not attempt to turn the rubber grip inside out--you simply want to unstick it and stretch it just enough to slide it off of the lens. If I remember correctly, removal of the trim ring in the front of the lens (where the lens data is printed) will allow you to see the pin and the fork. Some of the rings screw in, and others snap in. I THINK this one screws in, but don't remember for sure. You could remove it to confirm the problem, but I'd bet anything it's the bushing decayed away. It does make precise focusing an annoyance! Good luck, and happy shooting. Link to comment Share on other sites More sharing options...
hilbert5 Posted March 24, 2007 Author Share Posted March 24, 2007 Hi Alan, many thanks for this detailed information! Just to confirm: If it were the problem that you describe (which sounds very plausible to me as it explains the play only in one dimension) there would not be a way to fix it. Correct? Cheers,Ernst. Link to comment Share on other sites More sharing options...
miked10270 Posted March 25, 2007 Share Posted March 25, 2007 Hi Ernst, On a nFD lens, Mark is more than 99.9999% likely to be right, it'll be the screws under the focussing grip. What you describe is the early stages of the screws coming loose - they can't get any looser because of the rubber grip. This is a simple repair - one that I'd expect a camera tech to do in 5 minutes and as a freebie if you're already a customer. Mike. Link to comment Share on other sites More sharing options...
feanolas1 Posted March 26, 2007 Share Posted March 26, 2007 I would also bet on the bushing decay, but anyway you need to remove the rubber to access the screws... tighten the screws and you will see, if the looseness remains, you will have to replace the bushings! Link to comment Share on other sites More sharing options...
hilbert5 Posted March 28, 2007 Author Share Posted March 28, 2007 Thanks to all of you for your support! I removed the rubber and the screw beneth it was tightly fixed (actually all accessible screws are tight. So it's the bushing. Is there anything one can do about it (as to a possible replacement and a repair for an amateur like me)? Cheers, Ernst. Link to comment Share on other sites More sharing options...
feanolas1 Posted March 28, 2007 Share Posted March 28, 2007 I haven't opened a 2/35, but usually you have to unscrew these very same screws in order to desoliderise the external focus ring from the internal helicoid and remove the focus ring. Then you should actually see the bushings and be able to remove them. Replacement is another matter, I made do once with heatshrink tubing for electronics, but there are probably better sources. Link to comment Share on other sites More sharing options...
hilbert5 Posted March 29, 2007 Author Share Posted March 29, 2007 OK. Thanks to everybody. I keep you posted what happened after I will have opened the lens. Cheers, Ernst. Link to comment Share on other sites More sharing options...
alan_swartz Posted April 7, 2007 Share Posted April 7, 2007 Ernst, I haven't come up with a good substitute for the deteriorated plastic. Link to comment Share on other sites More sharing options...
marksuite Posted July 24, 2017 Share Posted July 24, 2017 I just bought a band.it instead, since its cheap and the focus ring will never wear out again, not to mention the better grip. They sell it on camerabandit.com Link to comment Share on other sites More sharing options...
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