Sigma Mini-Wide II - 1 Guardian - 0

guardian · Joined: 18 Mar 2009 Posts: 1747

I wish herewith to nominate the Sigma Mini-Wide II as the most difficult lens to clean and/or repair. If other forum members object, I insist this lens at least be granted its rightful place in the "Impossible MF Lenses to Clean/Repair" Hall of Fame. Here is the story:

I brought in this SMW II in Canon mount because it was cheap. Beeeeeg mistake.

The lens I later discovered has internal black dots/flakes. Probably some paint flaked off. I don't know. There is black stuff in there.

Not to worry. With access, the lens appears nevertheless entirely salvageable.

First, you had better have the right size friction tool to remove the name ring. I do. It was very tight, but it finally broke free uneventfully. No award so far.

Next, you discover instantly name ring removal has availed you nothing. You now face the retainer for the front lens element. It's small. I made special tooling and twisted. Nothing. Nothing at all. It would not budge. Long story short, I applied a LOT of acetone to that puppy before it (suddenly, unexpectedly, and finally) moved. With that retainer unscrewed, I felt the threads. They were sticky.

Removal of the first lens element brought no help. The black spots were deeper into the lens. I faced another retainer, the one for the second element. Fuggetaboutid. It would not budge. I applied acetone. I applied more acetone . . and more. I drowned the thing in acetone. Nothing. I brought special friction tooling to bear. It worked really well and I was applying a LOT of torque to that thing, darn near my full strength. Nothing. Nothing at all.

And so that's where things stand at this moment. Sigma, it seems to me, has glued this SMW II lens together!!!!

I rest my case.

DigiChromeEd · Joined: 29 Dec 2009 Posts: 3468 Location: Northern Ireland

I feel for you! Sad

I can't remove even the front element of a Konica Hexanon AR 3.5/135 to get to some fungus further in. Rolling Eyes

Excalibur · Expire: 2014-04-21

I suppose when this lens was made it was the start of the "throw away and buy another one " future.

Lloydy · Expire: 2022-01-01

I've got a partially disassembled one as well. Rolling Eyes

guardian · Joined: 18 Mar 2009 Posts: 1747

I appreciate the sympathetic responses. Thanks.

I'm thinking about the possibility of going in from the rear. It'll mean tearing off the mount; not a scenario I welcome. And if the rear element is glued into place there is no guarantee I'll be able to break it free.

Some months ago I had a Konica lens assembly I actually immersed in solvent in an effort to free it, all other efforts having come up short. That worked, except that:

The solvent also penetrated the bond between two joined lens elements in the rear group, much to my chagrin, creating a "wonderful" rainbow effect. I've not tried such an immersion approach since! Heat did not help. However the solvent eventually disappeared spontaneously from between the joined elements, but not until several weeks had passed.

The Japanese propensity for gluing lenses together is, I think, an Oriental frontal assault on would-be MF lens restorers. Sad

It is a really bad idea.