Some interesting comments on lens fungus

Discussion in 'Digital Cameras' started by Rich, Dec 6, 2011.

  1. Rich

    Rich Guest

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  2. Rich

    Me Guest

    Me, Dec 6, 2011
    #2
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  3. Rich

    Rich Guest

    Apparently one of the constituents of it generates acid and chelates
    metals. Could be how it effects glass.

    http://en.wikipedia.org/wiki/Siderophores
     
    Rich, Dec 6, 2011
    #3
  4. Rich

    PeterN Guest

    Which is what I said earlier on, in another thread. Pr did you
    conveniently forget.
     
    PeterN, Dec 6, 2011
    #4
  5. Rich

    Irwell Guest

    So it seems the lens fungus is very common and the
    "Oh my GOD! Cameras built in what was a SEWER not long ago!!!"
    remark was borderline yellow journalistic?
     
    Irwell, Dec 6, 2011
    #5
  6. So plastic is better?
    -- Doug
     
    Douglas Johnson, Dec 6, 2011
    #6
  7. Rich

    Bruce Guest


    It depends what you mean by "better".

    But yes, optical resins are probably better than glass when it comes
    to resisting fungal attack.
     
    Bruce, Dec 6, 2011
    #7
  8. Rich

    RichA Guest

    Why? It certainly makes the situation potentially much worse. The
    entire point of many of the observation of these people is that once
    the fungus gains a foothold, it cannot be gotten rid of permanently.
    Surely if a camera ends up with a million spore in it, it's far worse
    than if it has 100 spores.
     
    RichA, Dec 7, 2011
    #8
  9. Rich

    RichA Guest

    In this case, yet. However, the only plastic they are using in lenses
    is the aspheric side of hybrid elements and cheap lenses in bottom-
    barrel cameras.
     
    RichA, Dec 7, 2011
    #9
  10. Rich

    RichA Guest

    I'd agree with that, but the jury is out on if the fungus does this by
    accident, or if it is actually deriving nutrients and doing it "on
    purpose" to the glass.
     
    RichA, Dec 7, 2011
    #10
  11. Rich

    Irwell Guest

    It's Thailand, for Gawd's Sake.
     
    Irwell, Dec 7, 2011
    #11
  12. Rich

    tony cooper Guest

    Fungus is as immoral as a politician. It has no sense of right or
    wrong.
     
    tony cooper, Dec 7, 2011
    #12
  13. Rich

    Me Guest

    OK, so I was interested to see the "lens fungus" species identified -
    well kind of identified - after all the cite was from a forum consisting
    of interested parties who (presumably) aren't mycologists.
    (I'm not either - but a know a few)

    The fungus doesn't "eat" glass. It eats traces of organic matter on the
    surface of the glass. So it (apparently) chelates metals it needs from
    inorganic matter - optical glass.
    This seems a bit odd, as the species identified doesn't seem to be one
    that normally lives in locations where there'd be no shortage of food
    (carbon) which would already contain the trace elements it needs - as
    it's a common fungus found on and feeding on living tissue - it's "food
    source" would already contain what it needs, no point evolving to
    extract trace elements from (eg) rock if you live on a grape.
    My guess is the species isn't identified correctly.

    But I have no doubt that there will be other species which will eat
    plastic, and anyway, if it's a lens with internal "hybrid" elements,
    then the fungus already has a taste for the cements used to glue
    compound glass elements together, so presumably would be happy to eat
    the glue used to stick hybrid elements together. OTOH, most hybrid
    elements I'm aware of are large aspherical front elements, with the
    plastic bit on the outside.


    It would be nice to find a solution to the lens fungus problem which is
    less trouble than storing equipment in dehumidifier cabinets.
    I guess a gamma radiation source or x-ray machine could do the trick,
    but it's a bit of a hassle setting this up at home just to nuke lenses
    occasionally.
    There must be a way...
     
    Me, Dec 7, 2011
    #13
  14. Rich

    Eric Stevens Guest

    There are zillions of fungi. There is no reason why the one(s) which
    take hold in a flooded building are the ones which attack glass.

    Regards,

    Eric Stevens
     
    Eric Stevens, Dec 7, 2011
    #14
  15. Rich

    PeterN Guest

    Back to square one. SILICA IS NOT DIGESTIBLE. by any known earthly
    organism.
    Just admit you were wrong, or prove me wrong, with some peer reviewed
    research.
     
    PeterN, Dec 7, 2011
    #15
  16. Rich

    PeterN Guest

    On 12/7/2011 12:24 AM, tony cooper wrote:

    while politicians may be immoral or amoral, fungi are amoral.
     
    PeterN, Dec 7, 2011
    #16
  17. Rich

    RichA Guest

    Good thing few lenses are pure silica, huh? Metals, alkalines, etc.
     
    RichA, Dec 7, 2011
    #17
  18. Rich

    RichA Guest

    I don't know what the prevalence of that fungus is in that
    geographical area.
    Fugal spores move on the wind, they can go anywhere.
     
    RichA, Dec 7, 2011
    #18
  19. Rich

    RichA Guest

    UV light might work.
     
    RichA, Dec 7, 2011
    #19
  20. Rich

    Me Guest

    Apparently it does - to some extent.
     
    Me, Dec 7, 2011
    #20
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