Why don't you take a infected lens, store it with some of your good lenses for a
few months (in a monitored environment), then have them tested, and then YOU can
write the definitive text on the issue................
Otis Wright
Stan Halpin wrote:
> Thanks Dave and also Bob Blakely. I also have searched the web via Google
> and have so far found no definitive evidence that fungus spreads from lens
> to lens. I totally agree with Bob's logic:
>
> >> All fungus reproduce by microscopic (translate as too small to see) spores.
> >> The method of spore propagation is being carried on air currents. Every time
> >> you focus your lens near to far, air (with fungus spores) is forced out of
> >> the lens and some into your camera body. (Yes, camera bodies can get fungus
> >> too.) Put another lens on the body and focus far to near and you suck air
> >> (with spores?) into the lens. Will the spores germinate? This depends on
> >> conditions, especially humidity.
> >>
> >> I don't take chances.
>
> But like Dave I have found no clear evidence.
> For example, if an infested lens is a danger, then one might assume that the
> number of spores per liter of air sampled in a space where lenses are kept
> would be higher if some of the lenses are infested. Has anyone checked the
> air in a closet, cabinet, leather bag, nylon ripstop bag?
> For example, given similar conditions, is the likelihood of stored lenses
> being infested higher once an infested lens is introduced into the space?
> If there is data indicating a correlation between presence of an infested
> lens and the likelihood of additional infestation, could a meta-analysis
> show that what we have is not cause-effect {infested lens causes others to
> become infested} but common-cause {the conditions that encouraged growth of
> fungus in the first lens also encourage growth in other lenses.}
>
> Because it is logical, and because we know it is right doesn't make it
> right. I just wish I could see some solid empirical data . . . anybody up
> for a microbiology thesis project? And by the way, what is the minimum
> number of spores needed to achieve growth? One?
>
> Of course Bob's conclusion is the correct conservative one: don't take
> chances. And I won't. But I would like to be able to convince the
> [skeptical] seller that I have a real issue and am not just mindlessly
> passing on urban myths.
>
> Stan
>
> > From: "David Chang-Sang" <[EMAIL PROTECTED]>
> > Date: Wed, 20 Mar 2002 21:03:59 -0500
> > Subject: RE: Fungus sanity check please . . .
> >
> > Hi Stan,
> >
> > First let me say that I use your site ALL the time as a reference when I'm
> > looking for used Pentax lenses on Ebay or other places. It's a god send..
> > thank you.
> >
> > Now.. your fungus problem.
> > All I could find on the web that seemed to sort of validate your point was
> > the following:
> >
> > http://www.biotech.ufl.edu/EM/data/lenseatingfungi.html which is a
> > biotech/biomed account of some instances amongst some collegues at
> > university of florida
> >
> > http://www.chem.helsinki.fi/~toomas/photo/fungus/ an interesting page on
> > lens fungus with images and a particularly interesting statement that may
> > help you in your arguement:
> >
> > "If you use your equipment in damp environments, let it dry as soon as you
> > return into a drier room. Never leave your equipment in a closed
> > (splashproof) camera bag when it need not be there. Leather lens cases are
> > known to be especially bad, because leather is a natural product where fungi
> > can grow before they proceed on to the lens"
> >
> > The mere fact that the fungus can transfer from a leather lens case to a
> > lens may suggest it's ability to move/transfer from lens to lens should
> > lenses be stored together.
> >
> >
> > Most of the pages/sites I spotted are good at explaining why fungus grows
> > and how to stop it but not one of them actually stated that it does actually
> > "spread" from lens to lens.
> >
> > Hope this helps.
> >
> > Cheers<
> > Dave
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]]On Behalf Of Stan Halpin
> > Sent: Wednesday, March 20, 2002 8:12 PM
> > To: PDML
> > Subject: Fungus sanity check please . . .
> >
> >
> > I recently bought a used lens on eBay. It arrived with slightly smeared
> > glass. I cleaned the lens, front and back, and looked through and saw little
> > squiggly lines 1mm or so in length a few places around the edge of the front
> > element. Cleaned the front some more to be sure, and confirmed that the
> > little squiggly fuzzy lines are on the back side of the front element.
> > Fungus I said. Actually what I said first was something else that rhymes
> > with hoover. As Wendy would say.
> >
> > So I email the seller and tell him I don't want fungus. Fine, he says, send
> > it back. I could clean it, I says, but I could not be sure of sanitizing it,
> > and I don't want the fungus to spread to my other lenses. How about a
> > professional cleaning?
> >
> > The seller is willing to have me get an estimate for a professional CLA of
> > the lens. But he is also ridiculing the notion that a lens which is all
> > fungused up is in any way a danger to other lenses. Like, "how would the
> > fungus get out to 'infect' the other lenses!?!?"
> >
> > Tell me I am not crazy! Tell me I am not repeating a myth, that fungus is
> > "contagious" and destructive. Even better, give me the URL of an
> > authoritative source on this topic.
> >
> > Thanks.
> >
> > Stan
> -
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