Isco/Gottingen 4/180mm Tele-Westanar - Sonnar !

[imagedit]

Very nice.
I prefer the war torn looking lenses, as long as the optics are good.
Makes me think of how many people have got use out of it and what pictures they have taken.

[Pancolart]

[connloyalist]

Apologies for resurrecting an old thread.

Is the Isco 180mm f/4 really around 660 grams? I see these on eBay regularly but have never pulled the trigger on one yet because of the weight. For various reasons my limit is about 500 grams. But these lens would be right up my alley.

Regards, C.

[BrianSVP]

Looking at the pics on this thread and the linked ones just convinced me to make an offer on a fixer one one of these.

To anyone who has one, can you confirm that the exterior is plain black anodizing as it appears, and not overpainted? The one I made an offer on is rather worn, too, and it might be a nice candidate for a refinish.

[Dejan]

I've read their quite prone to lens separation (it can look like a small starburst on the glass). I'd pay attention to that as well.

[BrianSVP]

[Dejan]

Wow! That's really nice. It's one of the issues I know I could never solve. Well, not without spending more than I spend on most lenses, or trying risky hacks at home.
So I simply avoid some of the most notorious lenses (like Septons).

[BrianSVP]

It's not as intimidating as it looks, although now that methylene chloride strippers have been banned in the U.S., I typically have to use heat to separate lenses using synthetic adhesives, which is a little dicier. Older doublets using Canada Balsam separate easily with regular acetone. The cementing itself is fairly straightforward using NOA61 UV cure cement. The Isco should be here Monday. If it requires recementing, I'll add photos of the steps to this thread.

The Septon in theory should be easy to separate/recement, as the doublet is quite small, but I've never actually been able to successfully remove the retaining ring holding it into its housing. I actually have 4 of these lying around with varying degrees of separation awaiting my figuring out whether it's feasible or not.

Many unsuccessful attempts led me to believe the doublet that typically has separation (rear of the front cell) was permanently swaged in, but this guy in China seems to have successfully removed and repaired it. I once reached out to him using Google translate to see if he could let me know whether he lathed it out or successfully unscrewed it, but he never got back to me.

[paulhofseth]

I imagine that absolutely exact centering of the elements would be the biggest challenge when regluing

p.