I need to remove the first element on the front of a lense to remove a considerable amount of dust that has built up on the inside of the element. I have a proper wrench for the job but need to know if it is necessary to reposition the element exactly where it was. Also is there a seal under the mounting ring that will be disturbed? There are no local camera repair places I would trust to do this job. Any advice on this delicate procedure would be appreciated.

-- Ken Newcombe (kennewcombe@geocities.com), October 24, 1999

Answers

Ken,

It's difficult to say without knowing the lens you are talking about. I assume you are about to do this to an older manual focus lens though. I don't recall any special seals on the cheaper ones that I have taken apart, but I know that some of the very good lenses do have them. Generally, there is no need to reposition the glass rotationally in the same place, but it would be fairly easy to mark it with a felt tip pen just before removing it to make sure you got it back right. I didn't find the job particularly delicate either. Just make sure you clean off all the smudges on the inside before you close it up and be careful not to allow dirt or oil to touch the aperture blades.

-- Jim Strutz (jimstrutz@juno.com), October 25, 1999.