Hi Zuiko enthusiasts
I wrote to a highly respected NZ mycologist with whom I have had dealings
about fungi in a totally different matter. (Forestry).
I told him about our debate, and specifically asked about UV light as a killer
of fungus.
Here's my letter to him, followed by his reply.
It is noteworthy that he totally ignores the matter of UV light. Maybe that is
because it is not effective. I don't know.
Hello I**,
I wonder if some time you could spend a couple of your valuable minutes on
this topic.
I am also a member of a camera news-group (Olympus) on the internet, and
a current topic is fungus in camera lenses. This is a problem because (a) the
spidery hyphae make a mess of the images by reducing contrast and
sharpness, and (b) the by-products of their metabolism severely damage the
glass by etching the surface and permanently degrading the performance of
sometimes very expensive lenses. Often these days no replacement is
possible.
I'm not sure, but suspect that the species will include ascomycetes.
The same problem is bound to have arisen in laboratories with respect to
microscopes as well.
Some news-group members have suggested that periodic transmission of
UV light through the lenses will kill the fungi. I don't know if this is true,
and anyway, since the focus of infection is often between the rim of the lens
and the metal mount, if would be a temporary cure only, if at all.
I wonder if you can comment briefly and informally on this, and also advise if
any chemicals are recommended for use in microscopes as a prophylactic?
Sincerely,
Brian Swale <
Subject: Re: Fungi and lenses
Dear Brian
This is a major problem with microscope lenses in the tropics and some
manufacturers provide lenses for use in warm, moist countries. You might
have a look at one of the major microscope manufacturers web sites or
search on "fungi lenses" on the internet. I suspect, although I don't know,
that it is the coatings on the lenses that would be affected most. However, I
am sure that some fungi would grow between two closely appressed
surfaces just for the hell of it!
The problem arises when a lump of metal and glass goes through warming
and cooling cycles in a humid atmosphere when condensed water is dragged
into cracks and crevices around lenses. So the first thing you must do to
protect lenses from damage or further damage is to keep them in a dry
place. Hence the silica gel packs inside new camera boxes. As far as I am
aware once the damage is done it is too late. I once saw a class set of
Zeiss microscopes (very expensive) at the Universiti Pertanian Malaysia near
Kuala Lumpur that had been destroyed because it was necessary to turn the
air conditioning equipment off at night. I dismantled one of the lenses,
cleaned it with lens tissue and then reassembled it but the improvement was
at best 50%. Treating the lenses with fungicide will do little - prevention is
much better than trying to cure the problem after the event. Have you
thought about approaching a lense manufacturer to have the lens groups
resurfaced? An optician might be able to help.
Kind regards from a cool and moist Sweden.
I** H***
So; there we are. Some progress but not the final word.
Brian.
...................................................
No trumpet, no clarinet, no oboe;
Just a plain old p - i - a - n - o .
---------------------------------------------------
OM1, 2, and 3, Brian Swale, 140 Panorama Road,
OM4 and Zuiko. Christchurch 8008, N.Z.
Make great day, Tel +64 3 326 7447
THE way to go. http://homepages.caverock.net.nz/~bj/photography/
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