What to do with Lenses With Fungus

[John Olsen]

I sent my 100mm Schneider to Calumet in Chicago for a cleaning a few months back. It was the best investment I've made for a long time. Let Jose have a go at it.

[Leigh]

Fungi propagate by spores, but only when they are producing spores. That's when they are fuzzy. The flat mycelia of the vegetative stage usually seen on the surface of glass has no fruiting bodies, so the contagion risk is low...

So they make spores, as we all know.

If they're confined, like inside a lens or lens bag, they just sit there, waiting for someone to let them out so they can do their thing.

- Leigh

[RedSun]

Even without the apparent spores, fungus still grows. It just need the humidity and right temperature. All the original fungus started from nowhere, just from the thin air...

[Jim Graves]

Disclaimer: I'm no fungus expert ... however, there are fungus spores EVERYWHERE ... they will grow when the conditions are right.

I wouldn't worry about bringing new fungus spores into my house ... they're already there. And, they can be easily killed ultraviolet light (among other methods.)

The fungus question that I would worry about is whether the lens glass or coating has already been ruined.

[photobymike]

"There are about 75,000 scientifically identified species of fungi, with scientists believing there may be as many as a million fungal species yet unidentified. As differing species may look the same superficially, classifying them accurately is difficult, and usually requires the application of molecular tools such as DNA sequencing."

There are only a few species that like glass. They specialize on glass with some being very destructive with the waste chemicals they release etching the glass lenses. I am no fungi expert but if i remember my micro bio classes. Interesting thing about fungus infecting your camera it does damage to the glass sufaces only. You would think that it would do damage to the metal parts... i have never seen this happen... but i have seen glass etching... Two months ago bought a Mamiya RZ 50mm .... i could tell the rear element was cleaned of fungus but left etching on the element... .... sent back

yea fungus is everywhere but needs the right environment to propagate in and the right surface to make its home....

[Leigh]

As differing species may look the same superficially, classifying them accurately is difficult...

Henceforth we should demand that all fungi carry biometric-coded photo IDs.

Failure to do so would be punishable by deportation to Oz.

- Leigh

[Leigh]

Interesting thing about fungus infecting your camera it does damage to the glass surfaces only.

The explanation I was taught in camera repair school is:

The fungus lives on the magnesium fluoride anti-reflection coating that's applied to the glass.
The waste product produced is hydrofluoric acid, which etches the glass.

Sounds reasonable to me.

- Leigh

[photobymike]

sounds good to me also Leigh .... i am certainly not an expert, just a victim of this ... the 2 things i have learned .. i clean with iodine and seal and freeze suspected lenses....

found this page that was kind of interesting

http://www.truetex.com/lens_fungus.htm

[Steven Tribe]

The only etching damage from fungus attacks I have seen has been on coated lenses - mamiya TLR.

I have never seen aggressive fungus on any pre-Jena/Schott glas - even when the brass/aluminium alloy is half destroyed by a leaking roof in an shed!

Unless you place an infected lens next to a modern coated lens in a sealed container, they are no more dangerous than fresh country air.

[Sevo]

The fungus lives on the magnesium fluoride anti-reflection coating that's applied to the glass.
The waste product produced is hydrofluoric acid, which etches the glass.

Sounds reasonable to me.

Prove it, and your name will be taught alongside that of Charles Darwin. So far, sulfur bacteria are the only living thing we know to live on something non-organic, apart from plants and their photosynthesis.

While there are fungi that can thrive in the presence of chemical elements poisonous to just about every animal or plant, the fungi benefit from the lack of competition caused by these poisons rather than actively metabolizing them. What is more, fungi cannot photosynthesize, they essentially are scavengers and need organic matter to live on - to thrive inside a lens, the latter must provide some organic substrate for them, whether plastics, glue, algae or dust.

It is remotely possible that some side process in their metabolism converts MgFl to hydrofluoric acid, but it certainly is not the main object of their metabolism. Indeed, I think the most likely explanation is that coating damage is not "the fungus eating coatings/glass", but a matter of the humidity in the fungus infested lenses causing plain chemical corrosion between aluminium tubing and glass/coating, with the fungus not actively participating other than by excreting mild (compared to HFl) organic acids.