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  1. #1
    snaggs's Avatar
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    Can film get too cold -80c (-110f) or -77k

    My friend has a lab so I can store some film at -80c for nothing, or -77k for about $150 a year to cover LN2 consumption. Anybody else looked at this? What do I use for radiation? Are full lead containers required? I wont be stored with the nuclear isotopes but in the bio storage, so im only concerned with background radiation.

    Daniel.

  2. #2

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    Hmmm . . . . -77K ????? Really?

    [-80C would be approximately +193K, if I recall my physics correctly]
    Last edited by MartinP; 09-16-2012 at 10:05 AM. Click to view previous post history.

  3. #3
    snaggs's Avatar
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    Yeh, LN2, maybe I mean 77K.

  4. #4
    Alan W's Avatar
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    How long are you planning on storing this film?

  5. #5

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    It is routine to put X-Ray film at -80C to make it MORE sensitive to radiation (and thus fog).

    This has been known since the 1950s.

    http://iopscience.iop.org/0508-3443/...3_7_10_410.pdf

    Also no amout of lead will save your film from cosmic rays.

    I suggest you store it a -20 to lessen chemical degredation. You should get 5 years past the date for 400 speed, 10 years for 100 speed and maybe 25 years for 25 speed.
    I suggest unless the film you have is no longer made and can not be replaced just buy more small batches.
    Last edited by brianmquinn; 09-16-2012 at 11:48 AM. Click to view previous post history.

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    You can still buy Agfa camera film years after they stopped manufacture. They stored their uncut rolls at -10 C. I would assume that Agfa had studied long term storage and arriived at this temperature as optimal.

    Other factors are beta, gamma and cosmic radiation. An inch or so for beta radiation and several inches of lead to reduce any gamma radiation. You would need to store film in a deep salt mine to reduce cosmic rays.

    BTW, the Kelvin scale does not go lower than 0oK which is absolute zero so a temperature of -77oK is noonsensical. Whether a symbol is capitalized or not is important in science. A capital K is used for Kelvin temperature.
    Last edited by Gerald C Koch; 09-16-2012 at 02:09 PM. Click to view previous post history.
    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

  7. #7

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    [QUOTE=Gerald C Koch;1394858]You would need to store film in a deep salt mine to reduce cosmic rays.QUOTE]

    J. S. limited or was that unlimited but a largely one man business used to offer this service free of charge to the right or was that wrong people. He insisted they stayed with the film all the time

    Fortunately J.S. went bust in 1953. Good news sometimes when that kind of service disappears

    pentaxuser

  8. #8
    Steve Smith's Avatar
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    Quote Originally Posted by Gerald C Koch View Post
    BTW, the Kelvin scale does not go lower than 0oK

    It also doesn't need the degree symbol.


    Steve.
    "People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.

  9. #9

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    Quote Originally Posted by Steve Smith View Post
    It also doesn't need the degree symbol.
    Curious Fahrenheit, Celsius, and Rankin all use the degree sysmbol. As you say Kelvin doesn't. Never thought about it before. As someone once remarked, "The nice thing about standards is that there are so many of them."
    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

  10. #10
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    It's common to say degrees Kelvin, but incorrect. The reason is that it is an absolute scale rather than a relative scale. It's stated as (for example) 5500 kelvins (small k), or 5500K. Essentially, 'kelvin' replaces the word 'degree'.

    It used to be called degrees Kelvin, but that was changed.
    Last edited by lxdude; 09-17-2012 at 12:59 AM. Click to view previous post history.
    I do use a digital device in my photographic pursuits when necessary.
    When someone rags on me for using film, I use a middle digit, upraised.

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