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Message |
    
Robert Ewing
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 05, 2006 - 03:08 pm: | 
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Hi everyone. I have a nice 50mm 1.4 SSC lens with a dented locking ring. Its only a slight dent but enough to cause problems mounting the lens. I have a wrecked 50mm 1.8 lens and I was thinking of swapping the locking rings. Does this sound possible? I'm not sure how to start removing the locking ring. Do I have to strip the whole lens? Hope someone can offer a bit of advise. Even if its only to say "forget it"! Thanks in advance |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 05, 2006 - 05:19 pm: |
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No problem. Remove the small chrome slot-head screw that you can see in side of bayonet ring. Unscrew the ring and remove. Clean the threads on the replacement ring and the lens barrel and then apply a small amount of grease onto threads in ring. I use a Silicone grease that is normally supplied to lubricate the rubber seals in PVC soil/water pipes - this is readily available and gives a nice 'silky' feel to the ring. Replace the ring and screw up a couple of turns, carefully place lens on camera and continue to carefully rotate ring until lens is secure. Now replace the stop screw - do not tighten - and remove lens from body. You can now tighten the stop screw, but note that it is very easy to strip the threads in the soft alloy bayonet ring. I normally secure this screw by putting a small amount of the weakest thread-lock under the head of the screw and then just nipping the screw down.
I use a reversing ring to get the position of the bayonet ring correct, but you can use an extension tube. Use of ring or tube makes it very easy to replace stop screw. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 06, 2006 - 05:07 am: |
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Robert,
Brain not in gear when I wrote above. Only excuse is that all the breech rings that I have removed lately have been on macro items.
Yow will find TWO chrome slot head screws, remove both and then proceed as above. The actual bayonet stopper is a small metal arm held by the aforesaid screws. You will find that a dab of grease on the foot of stopper will help locate it when you re-screw ring.
If you locate stopper in correct place, you can match up the screw holes without placing lens on camera - when you reassemble. I find it quicker /easier to have lens on a mount - camera or reversing ring etc. |
Robert Ewing
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 06, 2006 - 03:35 pm: |
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Hi Glenn,
Thanks for the help. I will try it once I get myself a reversing ring, some grease and thread-lock. I'm so glad it's fixable. I've no experience repairing cameras although I'm pretty good with my hands and will tackle most things. I must look out my other faulty equipment and see if I can get it fixed too. This is a great forum. I know I have a Weston Euromaster meter with a broken glass. I'd like to replace it with Perspex. I've also a Pentax LX with a sticky mirror, a Pentax MX with a fault with either the hot shoe or sync socket and a little Rollei 35TE with a faulty meter! I'd better get posting! Thanks again :-) |
James Jones
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 07, 2006 - 09:54 am: |
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Robert, I know it sounds like a good idea to replace the Weston meter window with Perspex (what we call Plexiglas or Lucite) but that may cause a problem. This acrylic material retains static charge, and can attract the needle, causing it to deflect when there should be no reading. I had the same problem with a Heathkit benchtop voltmeter years ago--I would have to remove the meter faceplate and treat it with anti-static spray every now and then. Just something to think about. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 07, 2006 - 11:40 am: |
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Whilst the problem can be severe on analogue instruments carrying high voltages, the use of Perspex on exposure meters is not so problematic.
It is quite easy to place a small piece of metal foil around the edge of the 'window' to form an earth path to the case. However, with the advent of conductive paint the solution is even simpler. I routinely paint a thin earth bond line on plastic mounts, windows or other items where static can build up and attract dust etc. |
