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  1. #1
    Andre Noble's Avatar
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    Cav UV-C Light Create Penetrating Radiation = Potential Film Fog?

    Hello,
    I was researching ways to minimize background Gamma radiation exposure to frozen film stock, when I came across a diagram on this page http://www.reviss.com/resource/index.asp?lvl2_id=10 suggesting that UV-C radiation overlaps Gamma and X Ray radiation in wavelength.

    I actually run an enclosed type UV C germicidal lamp in the storage area of my lenses (to help minimize chance for lens glass fungus) and which is near a large freezer that I keep frozen film.

    I know it sounds far fetched that radiation from a germicidal UV C lamp in an enclosed plastic case could not only penetrate said case, but the radiation from the UV C could also penetrate the walls of freezer and fog film. But I have to ask to be sure.

    informed responses appreciated. Thanks in advance.
    Andre Noble, Beverly Hills California http://andrenoble.com/

  2. #2
    Eugen Mezei's Avatar
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    Quote Originally Posted by Andre Noble View Post
    I know it sounds far fetched that radiation from a germicidal UV C lamp in an enclosed plastic case could not only penetrate said case, but the radiation from the UV C could also penetrate the walls of freezer and fog film. But I have to ask to be sure.
    My answer may be not very informed.
    I read that UV-C will damage almost any avaible plastic or composite material. (Or to say it the other way around, nobody produces plastics resistent to UV-C as this radiation is not present at earths surface except when it is produced artificially. I guess some specialised plastics are produced for space missions.) An effective method to protect them is to wrap it in aluminium foil. So I'm pretty shure UV-C will not penetrate your freezer.

    I don't see any overlapping between Gamma and UV in that diagram. I see Gamma from 10^-15 to 10^-10 and UV above 10^-10 at about 10^-5.
    Howewer the text suggest water, concrete and lead to block Gamma. Put your freezer with film in the pool and you're set.

    I also intended to radiate some of my lenses wiht UV-C. As precaution and also for killing existing fungus.
    May I ask you for how long have you used UV-C on your lenses and if you could observe plastics going brittle or elsehow damaged?

    Greetings,
    Eugen

  3. #3
    Photo Engineer's Avatar
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    Here is part of your answer: http://en.wikipedia.org/wiki/Ultraviolet

    PE

  4. #4
    Andre Noble's Avatar
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    Eugen, I only sanitize (using UV-C) the air that circulates around the lens and using one of these: http://www.amazon.com/germguardian-G...019568-0664625. I dont shine UV C directly into lenses (as far as I know).

    PE, based on that wiki page, would you say the answer is "no" as in, no the UV C does not produce penetrating radiation that would pass through freezer to fog film over time then?
    Last edited by Andre Noble; 02-18-2013 at 12:16 PM. Click to view previous post history.
    Andre Noble, Beverly Hills California http://andrenoble.com/

  5. #5
    Photo Engineer's Avatar
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    The answer is no. UVC is not considered penetrating radiation at normal levels here on earth. Even in space, it was not observed to be a problem.

    PE

  6. #6
    Andre Noble's Avatar
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    Thanks Mr. Mowrey. I just stuff a pretty penny's worth of the last of your former employer's E6 films (Expry 2014) in said freezer. Want to be sure I'm doing everything possible to protect it over the upcoming years. Thnxs.
    Andre Noble, Beverly Hills California http://andrenoble.com/

  7. #7

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    The diagram that you cite is not drawn to scale so the answer is no.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery



 

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