Fixing a Kiron 28mm f/2.0 lens

[Jordan]

Repair gurus,

I have a very nice Kiron 28mm f/2.0 lens for Nikon that served me well for several years. About a year ago it started acting up -- essentially, it no longer stops down (the stop-down lever on the rear mount of the lens does nothing at any aperture setting).

A local repair shop quoted me a large sum of money to repair it (about double what I paid for it).

Is this the kind of repair I could undertake myself? If so, what tools would I need?

Thanks!

[John Koehrer]

If it doesn't stop down it's likely either oil in the blade housing or on the blades or the stop down linkage.
Linkage you may clean by just removing the mount, If you can flush clean the blades you may get to them by removing the front or rear elements & drop some Naptha in there.
I wouldn't take it apart.

[darinwc]

if I remember correctly on the kiron, I was able to remove the front element assembly completely by unscrewing it counter-clockwise.
It may have had a set screw on the side preventing it from being unscrewed.
Once the front element is removed, the aperture can be cleaned or comepletely removed and cleaned.

[Jordan]

Thanks for the advice, everyone. Given that I don't have the tools or solvents needed, it might have to remain a paper-weight for a while longer.

[lxdude]

There's a member here called Kiron Kid. He just might be able to help.

[wblynch]

I have a Kiron-made Vivitar that uses a little spring to stop the aperture down. Most other lenses that I've seen use the spring to reopen the aperture. Although a slowly returning aperture is annoying at least you can take photos.

On mine, the spring has become so weak that it won't close at all. I wonder if yours has the same problem.

I wish I knew where to obtain a replacement spring.

[Jordan]

With this lens it may indeed be a spring issue, because there is absolutely no resistance when I slide the stop-down lever. In any case, the lens has gone to someone who can use it more (I traded it to someone local in exchange for a bunch of Velvia!)