fungus or what?

[laptoprob]

My beloved Sonnar copy Steinheil Quinon has developed something I have never seen before. Is this fungus or what? It has extended a lot since I got the lens about a year ago. It is located between the rear two cemented lenses.
Is there a cure?

For the repair fora discussion: There are a lot of general questions like these. I really don't get the logic behind the growing number of different fora.

 

[laptoprob]

Come on!
someone around here should recognize this!

 

[harry01562]

I'm more inclined to say you may have a balsam/adhesive seperation problem than fungus. Most of that has an amoeba-like look, or whispy tendrils, not the appearance of yours.
The good news is it can be fixed by recementing, the bad news is it's usually expensive. Places like Focal Point, I believe, are set up to do this work, which requires some specialized equipment. You might try getting in touch with them. Other places may tell you they can do the job, and just send it out and add their percentage. Always best to deal with the source.
If you offer to send them a photo of the damage, they can probably give you at least a tentative analysis. If they do, they may also include an estimate.
BTW, have you used the lens? The damage may increase flare, but not have much other effect.

Harry

 

[harry01562]

Noticed you are in Holland.. I know there are places in the UK where they can do the work. You might try going to an optical/telescope type store and ask for repair advise. Lenses are lenses, but they may not want to attempt to disassemble without the knowledge. A place as diverse as Holland should have at least one place that can do the work.

Harry

 

[rokkor]

Call Will van Manen Kamera-service at 079-3163339 (Zoetermeer) and ask him if he can fix it...

 

[laptoprob]

I dealt with Will before. Good bloke afaik. The lens still is functioning well. It adds a dreamy soft focus blur to highlights.
I had a focus helical problem as well but that is solved. Now I know at least how to take it apart!
If it really is delamination of those lens parts there is no hurry. The lenses will then slowly come apart by themselves, without help. I will see how it goes.
Any clue of what circumstances might speed up or slow down? Higher temperature and humidity will speed up I guess.

 

[kinoglass]

Heat and more heat. You can boil it with water in a cooking pot (put a paper napkin under the lens) until it comes apart with a gentle slide or a dry job in the kitchen oven for an hour at 100-150 degrees C . The cement will melt and the two lenses will come loose. Actually the top lens will slide off on its own weight. Acetone will clean the surfaces of any left over cement (most probably Canadian balm). To re-cement find out what is available in Holland in very small quantities. Modern optical cements do cure hard in minutes under sun or ultraviolet light. They are much harder to decement than good old organic Canadian balm. Centering the two lenses before cementing can be challenging. The amount need it is less than a drop, pressuring together the glasses will expand de covering surface of the dropplet and reduce the thickness. I have done it many times with succes.

 

[laptoprob]

Thanks! So how did you do the recementing and especially the centering?
Having done this many times makes you an expert, I guess.

 

[kinoglass]

I am an expert in taking risks! Well, there are two types of cemented lenses, if the lenses have the same external diameter, before you apply the light to cure the cement, rotate the lenses checking they are as centered. Some people will reinsert the lenses in the mount to assure perfect centering. I have never done it that way for fear of cementing the lenses to the mount. Other lenses have different outside diameters and holding them in perfect centering will require a simple jig or fixture to hold the pieces in place, soft wood shaped to dimension works fine. It is all fun work. Don't drop the lenses, don't burn yourself, don't breath the acetone and don't scratch the lens coating when cleaning. Good luck!

 

[laptoprob]

Thanks a lot! The lenses have the same diameter. I will try to get a suitable cement for it.
Life is full of don'ts. Doing only do's is no fun at all, right?

 

[clintock]

Here in the US, a cement that will work is sold at do-it-yourself automobile repair stores. It's a small vial of liquid sold with a syringe as a kit for repairing the glass of one's windscreen after a stone strike. The liquid has the same index of refraction as glass and cures in UV light. Another possible way is to bother a physics laboratory, as they must routinley affix crystals to glass-fronted photomultiplier tubes using balsaam or it's modern substitute, maybe a bored lab tech will be keen to help.

 

[Chad]

When did lens makers stop using balm? I ask because my uncle's favorite SLR lens (circa 1970's) has fungus between two cemented lenses.



Chad