And, then comes the uncurable problem of fungus having eaten away at the lens
coating.
Larry
Brian Swale wrote:
> Since discovering some fungus on three of my "new" lenses, I have been
> thinking about this somewhat.
>
> Maybe it is time to apply a little logic and scientific knowledge to the
> problem. I have no idea where this note is headed, but anyway, here goes.
>
> (And as I write this the thought occurs to me that here is a prime research
> topic for a Masters or PhD student - and I wonder if any anywhere have
> tackled it.)
>
> My relevant background is that I did three years undergraduate study of
> botany before doing my Forestry masterate, and fungi were included. I have
> also grown grapes at home. Some fungi love grapes. I had to learn a bit more.
>
> Fungi are plants. Plants without chlorophyll. Usually, they need what other
> plants need otherwise - a little water, and nutrients (these can sometimes be
> somewhat unusual).
>
> What you see when you look with shocked amazement through your
> infected lens is semi-transparent tubes (the hyphae, or body, of the fungus),
> wandering over the surface of your precious glass. And that's it. The whole
> plant. Fungi also usually reproduce my seeds - in their case, minute spores.
> I have never seen fruiting bodies or sporophylls on fungus in a lens, though
> no doubt it is possible. They might look like a string of tiny beads on a
> slightly different style of hyphus.
>
> Fungi have adapted to a wide range of foods; there is one well-known
> species that loves jet engine kerosine so much that it can multiply to such a
> concentration as to clog the fuel filters.
>
> Fungi have poisons.
>
> String ethyl alcohol is one (eg strong vodka, surgical spirit), and strong
> methyl alcohol is another. So are copper salts, boron salts, sulphur dioxide
> gas. Vinegar or acetic acid is a very good antiseptic that "never" goes off.
> And, apparently, the natural skin oils of humans.
>
> Strong alcohol also dehydrates the fungus and quickly dehydrated fungi
> usually die.
>
> So; I reckon that once you have removed the visible hyphae from the surface
> of the lens - that should be it. I can't see the logic in swabbing the lens
> 30 or
> 40 times more. If you can't see the hyphae, and you have poisoned the
> surface with alcohol, then they're probably gone.
>
> But there could be a reservoir of hyphae and/or spores being produced on the
> metal surfaces of the lens body - I don't know.
>
> What photographers need to know is what species of fungi are involved, what
> they feed on and what poisons them - and what can safely be left behind on
> the surfaces to retard their regrowth - and the germination of fresh spores.
>
> I must talk to the local university botany department / microbiology
> department.
>
> Cheers, Brian.
>
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