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Septon separation anxiety.
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PostPosted: Sat Feb 03, 2018 8:34 pm    Post subject: Septon separation anxiety. Reply with quote

I recently acquired a voigtlander septon 50mm f2 in remarkably good shape. I know most of the septons extant suffer from separtion. My is not (yet) afflicted. I am hoping to not have it occur. Does anyone know of techniques for preventing it? I normally keep all my lenses in a hard case with moisture absorption packets.


PostPosted: Sat Feb 03, 2018 9:56 pm    Post subject: Reply with quote

I'm guessing also keep it cool.


PostPosted: Sat Feb 03, 2018 11:38 pm    Post subject: Reply with quote

Yes, keep cool, do not suffer in advance. Laugh 1
A 50 year old lens that has not suffered from separation until now, will be perfect for the next 50 years. Twisted Evil


PostPosted: Sat Feb 03, 2018 11:47 pm    Post subject: Reply with quote

I think separation is most often the result of a sharp knock to the lens. Sustained vibration can also give the same problem. Having said that, flaws in the original balsaming process can cause unpredictable "spontaneous" failure many years after manufacture. (Sorry, Gerald!) The appearance of the tell-tale "Newton's Rings" doesn't necessarily mean that results will be greatly affected - if at all - but it does affect value, so best to treat lenses with some care.


PostPosted: Mon Feb 05, 2018 5:43 pm    Post subject: Reply with quote

As you can see, the scheme is the same of the Planar 80/2,8 for Hasselblad

http://www.der-klinterklater.de/grafiken/septon_k.gif

So, you can see that the separation only can exist in 3° and 4° elements (3° group) or in 5° and 6° elements (5° group).


PostPosted: Mon Feb 05, 2018 7:02 pm    Post subject: Reply with quote

I have a one with excellent glass too without separation. I keep it in dry cabin all the time. Wink


PostPosted: Tue Feb 06, 2018 1:36 pm    Post subject: Reply with quote

I'd guess dry environment on long term hurts such lens. But you can choose your menace then: fungus or separation Wink.


PostPosted: Tue Feb 06, 2018 1:42 pm    Post subject: Reply with quote

It would be cool if some member of this forum would specialize in elements gluing process offering "cheap" service.


PostPosted: Tue Feb 06, 2018 8:36 pm    Post subject: Reply with quote

Pancolart wrote:
It would be cool if some member of this forum would specialize in elements gluing process offering "cheap" service.


I can't remember which episode, but the guys on the Film Photography podcast were talking about someone's success in curing his separation problem by putting the element in the oven on a low temp.

I have no knowledge other than the above hearsay.


PostPosted: Tue Feb 06, 2018 10:04 pm    Post subject: Reply with quote

Sciolist wrote:
Pancolart wrote:
It would be cool if some member of this forum would specialize in elements gluing process offering "cheap" service.


I can't remember which episode, but the guys on the Film Photography podcast were talking about someone's success in curing his separation problem by putting the element in the oven on a low temp.

I have no knowledge other than the above hearsay.


I am sure there is some chance it works but doing it with expensive Septon huh, risky. Quite high temperature would need to be reached and success would depend also if elements are pressed together. They can easily crack so margin for error is very thin.


PostPosted: Tue Feb 06, 2018 10:34 pm    Post subject: Reply with quote

Pancolart wrote:
Sciolist wrote:
Pancolart wrote:
It would be cool if some member of this forum would specialize in elements gluing process offering "cheap" service.


I can't remember which episode, but the guys on the Film Photography podcast were talking about someone's success in curing his separation problem by putting the element in the oven on a low temp.

I have no knowledge other than the above hearsay.


I am sure there is some chance it works but doing it with expensive Septon huh, risky. Quite high temperature would need to be reached and success would depend also if elements are pressed together. They can easily crack so margin for error is very thin.


Are you familiar with this, Pancolart? -

Bond Failures: Causes and Remedies, by Summers Optical

http://web.archive.org/web/20070220153603/http://www.emsdiasum.com/summers/optical/cements/manual/manual.html


PostPosted: Wed Feb 07, 2018 10:43 am    Post subject: Reply with quote

Very informative, thanks for the link!