Removing fungus from lens elements

[Captain Slack]

Interesting article on PetaPixel:

http://petapixel.com/2016/09/29/remove-fungus-lens/How to remove fungus from a lens.

Haven't tried it myself and I'm not sure I will giving the amount of surgery involved. Thought I'd pass it on, regardless.

[PFMcFarland]

That's a good explanation of the process. I've so far not had to resort to such measures (the peroxide/ammonia mix), but will keep it in mind next time. This is a much easier operation to do on a fixed focus lens than on a zoom, which seems to be the type that gets fungus much easier.

PF

[GrahamS]

I will just add a note here (and this is where we really need to have the NelsonFoto Forums database available again because there was a ten page thread there on this subject) the article by Tom Leonard only deals with a certain type of fungus which does not etch the surface of the glass or coating. If this has occurred, it is indeed necessary to remove the etch marks mechanically. The only way to do this is to polish the etch marks out. I was fortunate enough to meet a very charming old (relative to me at the time) gentleman at Photokina who was an optical engineer who had retired from the Olympus factory. The subject of fungus restoration came up and he told me that, to polish fungus marks out of a lens, he had always used PONDS COLD CREAM (the cream that women use to remove makeup, the non perfumed type) applied with the tip of a finger, NOT A CLOTH. He said that Ponds Cold Cream is one of the finest polishing compounds and that the human fingertip is a perfect applicator, provided that the fingernail is cut very short as a precaution against inadvertent contact.

The technique is to remove all traces of the fungus first, using chemical means and then to lightly rub the lens surface with a dab of cold cream, with a small circular motion starting around the edge and progressing towards the centre (Not a continuous circular motion but small circles) Don't expect quick results, it takes hours and hours. The cream should be removed with isopropyl alcohol to inspect the lens surface for progress.

I have used this technique and can confirm that it works. The degree of success is directly proportional to one's patience and diligence.

[LarryD]

Outstanding Information.