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Is this crystallization of the coating?
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PostPosted: Tue Jan 18, 2022 4:08 pm    Post subject: Is this crystallization of the coating? Reply with quote
I bought this Breolina to compare with one of my favorite 100s the Topcon re 100mm 2.8. It came in and at first glance looked really clear. Then I noticed these aberrant anomalies:


PostPosted: Tue Jan 18, 2022 4:26 pm    Post subject: Reply with quote
That is so weird yet they look like little flowers.


PostPosted: Tue Jan 18, 2022 4:29 pm    Post subject: Reply with quote
cute, should give some interesting flare effects shooting into the light.


PostPosted: Tue Jan 18, 2022 5:23 pm    Post subject: Reply with quote
I've seen that before. Sure it's no fungus?


PostPosted: Tue Jan 18, 2022 6:28 pm    Post subject: Reply with quote
It is hard to see from the image;

This could well be fungus, but I have also seen old and progressively hardened Canada balsam separation start like that. If it is indeed crystallisation, my bet would be on old balsam rather than a coating.


PostPosted: Tue Jan 18, 2022 8:35 pm    Post subject: Reply with quote
I really doubt its fungus, they are all symmetrical and various sizes and all have the exact same shape. I have some better shots I'll try to get some on here. They reflect light like a mirror. They look like little snowflakes when you get the lighting just right.


PostPosted: Tue Jan 18, 2022 9:00 pm    Post subject: Reply with quote
Oil splashes?

Doesn't look like fungus to me.

Try to clean may reveal other possibilities...


PostPosted: Tue Jan 18, 2022 9:21 pm    Post subject: Reply with quote
If you click the image, then click the image that opens in the new tab, it is pretty clear it is not fungus. Looks like 1970's cartoon flowers Laugh 1

Looks to me like something is coming unglued.


PostPosted: Tue Jan 18, 2022 9:47 pm    Post subject: Reply with quote
Knudsen wrote:
If you click the image, then click the image that opens in the new tab, it is pretty clear it is not fungus. Looks like 1970's cartoon flowers Laugh 1

Looks to me like something is coming unglued.


Yes, I could see it enlarged now.

100% balsam separation. Sometimes this starts like that in the middle of a lens.

Here are a couple of other balsam separation examples of similar type I grabbed from the web (quite beautiful some, really):


Markus Keinath - Lens Separation Repair - 4photos.de
http://www.4photos.de/camera-diy/Delamination-Separation-Repair.html




https://9gag.com/gag/aVw6nQP



PostPosted: Tue Jan 18, 2022 10:08 pm    Post subject: Reply with quote
Can be cured by gentle warming?


PostPosted: Tue Jan 18, 2022 10:17 pm    Post subject: Reply with quote
RokkorDoctor wrote:


100% balsam separation. Sometimes this starts like that in the middle of a lens.



I had a Pentacon 135 2.8 (1st) and had something very similar. I thought it was a tiny bit of oil, and so small it was not worth it to dismantle. Now I see what it really was... Smile


PostPosted: Wed Jan 19, 2022 6:38 pm    Post subject: Reply with quote
here is another shot with the light reflecting off of it. It might be separation. It seems odd it would progress in such an unusual pattern, at multiple loci. I might take it apart and see if its on the surface or in a cemented component. As mentioned the reason I bought the darn thing was to compare with the same FL of Topcon RE which it bears more than a passing resemblance. I will start a new thread for that.



PostPosted: Wed Jan 19, 2022 7:25 pm    Post subject: Reply with quote
visualopsins wrote:
Can be cured by gentle warming?

Separation surely. No, don't warm it, there is good chance problem will grow, whereas if left alone it could remain inert for years.


PostPosted: Thu Jan 20, 2022 12:50 pm    Post subject: Reply with quote
[quote="jamaeolus"]here is another shot with the light reflecting off of it. It might be separation. It seems odd it would progress in such an unusual pattern, at multiple loci.


For what it's worth, the pattern (dendritic growth) is very common in crystal growth kinetics found in nature, such as when frost forms on your car windshield or when metals solidify from a liquid to a solid state. Simply put, it is the most thermodynamically likely shape to occur in these circumstances. Perhaps this can also occur during the delamination of optical elements as well!






PostPosted: Thu Jan 20, 2022 12:59 pm    Post subject: Reply with quote
And this is how life started Wink.

Last edited by Pancolart on Thu Jan 20, 2022 1:33 pm; edited 1 time in total


PostPosted: Thu Jan 20, 2022 1:30 pm    Post subject: Reply with quote
pdccameras wrote:
For what it's worth, the pattern (dendritic growth) is very common in crystal growth kinetics found in nature, such as when frost forms on your car windshield or when metals solidify from a liquid to a solid state. Simply put, it is the most thermodynamically likely shape to occur in these circumstances. Perhaps this can also occur during the delamination of optical elements as well!


This is definitely separation, I had something similar on the Schneider lens once. Physically it is much closer to Saffman–Taylor instability (interaction between Canada balsam and air): https://www.wikiwand.com/en/Saffman%E2%80%93Taylor_instability

I have seen it during my study at the University in Hele-Shaw cells and have learned the whole theory behind, which is completely forgotten by me now.


PostPosted: Thu Jan 20, 2022 4:21 pm    Post subject: Reply with quote
Max78 wrote:

I have seen it during my study at the University in Hele-Shaw cells and have learned the whole theory behind, which is completely forgotten by me now.


Not completely I would suggest! Wink.

I had never even heard of this. Very interesting. I love learning about these things on this forum! Like 1 small


PostPosted: Thu Jan 20, 2022 8:10 pm    Post subject: Reply with quote
Max78 wrote:
pdccameras wrote:
For what it's worth, the pattern (dendritic growth) is very common in crystal growth kinetics found in nature, such as when frost forms on your car windshield or when metals solidify from a liquid to a solid state. Simply put, it is the most thermodynamically likely shape to occur in these circumstances. Perhaps this can also occur during the delamination of optical elements as well!


This is definitely separation, I had something similar on the Schneider lens once. Physically it is much closer to Saffman–Taylor instability (interaction between Canada balsam and air): https://www.wikiwand.com/en/Saffman%E2%80%93Taylor_instability

I have seen it during my study at the University in Hele-Shaw cells and have learned the whole theory behind, which is completely forgotten by me now.


Fascinating! So the driving force is a density gradient as opposed to temperature or concentration, but the morphologies are more or less similar to dendritic solidification.

In any case, I too have seen this phenomenon in a few lenses (not all Schneider). In my experience it is often the start of something that can get worse over time, but usually fairly slowly, and when it is the size you have shown in your images, it does not drastically affect IQ, if at all.

P.


PostPosted: Thu Jan 20, 2022 9:48 pm    Post subject: Reply with quote
RokkorDoctor wrote:
Knudsen wrote:
If you click the image, then click the image that opens in the new tab, it is pretty clear it is not fungus. Looks like 1970's cartoon flowers Laugh 1

Looks to me like something is coming unglued.


Yes, I could see it enlarged now.

100% balsam separation. Sometimes this starts like that in the middle of a lens.

Here are a couple of other balsam separation examples of similar type I grabbed from the web (quite beautiful some, really):


Markus Keinath - Lens Separation Repair - 4photos.de
http://www.4photos.de/camera-diy/Delamination-Separation-Repair.html




https://9gag.com/gag/aVw6nQP




Thanks for this info! I bought Carl Zeiss Jena Kipronar 90/1.9 from late 1940's with 3 of these in a front lens. From the link you have posted it looks like reparing this is not that difficult! Need to get my hands on Canadian balsam now
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