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- Jul 26, 2009
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- 35mm
This got ignored somehow. For 700-900$ I’d do it asap.
Ouch.
As a lens designer, I have a grasp of the stresses induced in the glass at the temperatures required to melt the uv adhesive used in the Summarex. The glasstypes expand at different rates, but the adhesive is preventing them from shifting with respect to each other. The result is a massive buildup of stress before the glass transition temperature of the cured adhesive is reach. The glass is pretty much guaranteed to fail just like you describe, even if they don’t receive thermal shock from carefully controlling temperature increase. Even thermal expansion coefficient matched flints and crowns undergo extreme stress.
Solvent soak for several weeks is the only way to safely separate uv adhesive bonded doublets. In all the time I’ve been working in optics and especially repairing lenses, I’ve never attempted separating uv adhesive bonded doublets with heat.
Summarex… I think I have the prescription for that lens. It’s theoretically possible to have a new doublet fabricated, though the cost is likely in the $700-$900 range.
We’re talking custom, very high precision glass here. No way that is going to be so relatively cheap. Someone would probably do a passable shot at it for that money.This got ignored somehow. For 700-900$ I’d do it asap.
We’re talking custom, very high precision glass here. No way that is going to be so relatively cheap. Someone would probably do a passable shot at it for that money.
But the whole point of the lens would be lost. It’s all about those last ten to one percent.
Putting $700-900 lens elements into a lens like this would have only made it that much more expensive to owner and adding value. In fact the lens would never again be called what it once was.This got ignored somehow. For 700-900$ I’d do it asap.
Putting $700-900 lens elements into a lens like this would have only made it that much more expensive to owner and adding value. In fact the lens would never again be called what it once was.
that aside from this rather silly suggestion as a possible fix. Probably why it “missed somehow”
I was not questioning your involvement nor knowledge in lens design, there would be no point to that anyways as in itself not relevant to my responseMaybe silly from your perspective not understanding how it could be done, but from my perspective as a professional lens designer who has optics fabricated and fielded for a living — including life cycle support of fielded systems — it’s a viable solution if the original build was valuable enough and the information was available.
We’re talking custom, very high precision glass here. No way that is going to be so relatively cheap. Someone would probably do a passable shot at it for that money.
But the whole point of the lens would be lost. It’s all about those last ten to one percent.
We haven't heard from the OP for about 3 pages. I wonder what he has decided and/or done about his problem?
Hopefully, he's not in custody awaiting arraignment.
Thanks to everyone for your thoughtful comments and suggestions.
Yes, my Summarex was easily worth between $3000 and $4000, if the fungus could have been successfully removed.
This Summarex is the first version, complete with original caps and shade, and is the lens pictured in one of Jim Lager's Illustrated Leica Lens Guides.
I had no idea that attempting to remove the fungus was so dangerous.
The worst outcome that I anticipated was the failure to remove the fungus due to the internal glass having been permanently etched.
I could have lived with the etching because the lens was still useable.
But, my repairman did not disclose the possibility of total lens destruction, prior to accepting this job.
Maybe I would have taken the risk anyway....I don't know.
In the end, the 40-year relationship with my repairman is worth more to me than this monetary loss.
I've learned an expensive lesson with respect to future repairs of rare vintage lenses.
I say tell him your thoughts on this. More or less what you wrote here.Thanks to everyone for your thoughtful comments and suggestions.
Yes, my Summarex was easily worth between $3000 and $4000, if the fungus could have been successfully removed.
This Summarex is the first version, complete with original caps and shade, and is the lens pictured in one of Jim Lager's Illustrated Leica Lens Guides.
I had no idea that attempting to remove the fungus was so dangerous.
The worst outcome that I anticipated was the failure to remove the fungus due to the internal glass having been permanently etched.
I could have lived with the etching because the lens was still useable.
But, my repairman did not disclose the possibility of total lens destruction, prior to accepting this job.
Maybe I would have taken the risk anyway....I don't know.
In the end, the 40-year relationship with my repairman is worth more to me than this monetary loss.
I've learned an expensive lesson with respect to future repairs of rare vintage lenses.
The threat of an early morning knock on the door by the Bailiff's can work wonders. Once an order has been signed by a judge in a county court there is very little that the person can do. Either he pays, or his goods and belongings can be seized and ultimately he could be made bankrupt which means all access to money is closed off, no credit, loans, if other words he is stuffed!
Agree. That would make things clear on both sides. Can't put enough emphasis on the polite part. Thaty would make for a healthy relationship.I say tell him your thoughts on this. More or less what you wrote here.
Of course be polite and perhaps put a by more emphasis in the “I appreciate your work and our relationship” part.
That will clear the air, while at the same time given him some useful feedback.
If you can truly handle it this way, kudos to you. If I read it right though, next job will not be a simple take-it-and-fix-it "as best you can".Thanks to everyone for your thoughtful comments and suggestions.
Yes, my Summarex was easily worth between $3000 and $4000, if the fungus could have been successfully removed.
This Summarex is the first version, complete with original caps and shade, and is the lens pictured in one of Jim Lager's Illustrated Leica Lens Guides.
I had no idea that attempting to remove the fungus was so dangerous.
The worst outcome that I anticipated was the failure to remove the fungus due to the internal glass having been permanently etched.
I could have lived with the etching because the lens was still useable.
But, my repairman did not disclose the possibility of total lens destruction, prior to accepting this job.
Maybe I would have taken the risk anyway....I don't know.
In the end, the 40-year relationship with my repairman is worth more to me than this monetary loss.
I've learned an expensive lesson with respect to future repairs of rare vintage lenses.
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