fungus on polarizing filter

[Munich]

Some fungus inside a pol filter before I attempt to clean it away.
Nikon 5x KNE IR 5x 0.13 on a Leitz Elpro 2 as a tube lens, Oly EM5 MK2


100%

[enricosavazzi]

Some fungus inside a pol filter before I attempt to clean it away.

Interesting picture, but it does not look like fungus to me. My best bet is that the Canada balsam used to glue the plastic polarizing material to a glass sheet has melted due to age and/or overheating, and what you see is a fractal-shaped bubble between the two materials. If so, there is no way to clean it from the outside.

I have seen this type of delamination in old enlarger lenses, probably with the same cause although located between cemented glass elements.

[Munich]

Thank you for your comment. I am sure you are right. Another image at 50x did not show any features.
I will try to take the filter apart. As it is a large well sealed BW polarizer, I expect to have a hard time.

[Olympusman]

1.0 Isn't nature beautiful?

2.0 Nature always finds a way.


Mike