I decided to tear apart my cheapie Sigma 28 f/2.8 mini-wide today because something condensed on the elements inside. I wasn't too concerned, I've pulled lenses apart before and frankly wasn't going to be to upset if I screwed up this lens.

I got things cleaned up and mostly reassembled, but am having difficulty with the foucing ring. The inner group has th coarse thread for focus, there is a reverse thread lock ring that the focus ring attaches to. The inner group and lockring to body is where I'm having trouble. Anyone have ever dealt with these? Anyone have service instructions? Or know where I can find them? This lens isn't worth having a pro work on, I'm not ready to throw it in the trash yet either.


-Xander