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  1. #21

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    Quote Originally Posted by Photo Engineer View Post
    Read my post above. I heard Henry's first presentation on dye stability in the 80s, when I first met him. I supplied part of the data used by Dr. Tuite at the same session that showed Kodak's POV.

    Henry uses the Fuji test method just about exclusively and this causes his data to look like theirs. The point of my comment here is not to say one is better or worse, but merely that test conditions change the results of image stability by a big amount!

    PE
    We have a joke in the consulting world that goes:

    Q: What's the difference between terrorists and methodologists?

    A: You can negotiate with terrorists.
    Digital Photography is just "why-tech" not "high tech"..

  2. #22

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    Quote Originally Posted by Photo Engineer View Post
    Kodak testing may seem self serving but it was developed through thousands of hours of experimentation and tests in the real world.

    The same comments positive or negative may be said about Fuji.

    PE
    Agreed.

    I don't think there are a lot of people who realize how difficult it is to design an effective experiment. Looking back on my time in graduate school I am reminded of a quote attributed to Thomas Edison:

    Results! Why, man, I have gotten a lot of results. I know several thousand things that won't work.

    I don't claim to know much about the study of archival stability. I do know that there are some who have published work on the phenomena of image degradation at the level of applied physics (activation energies, transition states, etc.) in an effort to explain its mechanisms. I'd be interested to hear what those models predict and how well they agree with Wilhelm's observations. I'd be even more interested to learn whether any of Wilhelm's owns publications cite these works.
    Digital Photography is just "why-tech" not "high tech"..

  3. #23

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    Quote Originally Posted by aldevo View Post
    There's a few things you'd do well to remember about Henry Wilhelm

    a) He's a paid consultant.
    b) FujiFilm is one of his clients (http://en.wikipedia.org/wiki/Wilhelm_Imaging_Research)
    c) Kodak has never been one of his clients

    I would not place my trust in any (any) scientist who licenses his findings for use by commerical concerns, as Wilhelm so obviously does.
    The groundbreaking measurements, the article in Science magazine and the Book considered as being the reference work in this topic have all been done 15 to 20 years ago, when e. g. Fuji's color print paper initially performed as poolly as Kodak's. But at the time of the book's publication, Fuji had already begun to improve.

    An office desktop at the workplace requires 500 Lux of illumination, equivalent to about 1/30 s exposure time at f/2,8 and ISO 100/21° (calculated from summer sun at noon ~ 100000 Lux and f/11-16, 1/125 s meter reading).

    120 Lux (Lux is a terrible relative unit based on the eye's sensitivity rather than on the true light energy in J/m2) is practically too dim to read.

    Compare also the film dark storage stability prediction for the latest generation of slide films: Fuji claims almost 100 years at 25 °C and 70 % relative humidity (Astia 100F/Sensia 100, Velvia 100 and 100F, Provia 400X) Kodak 80 years, but at 10 °C and 15 - 25 % r. H. (Elitechrome 100 G/GX) - so for your Fuji slides, you don't need to buy a fridge?

    If underperformers set their own standards, that's suspicious. I do however not see a bias of interest if an expert in science and technology is commissioned by private customers with consulting, product testing, and expert reviews, even if the results aren't intended primarily for publication, as long as the relationships are disclosed.

  4. #24

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    Interesting point about the longevity of Fuji slide film at room temp and normal humidity. It clearly means that no-one should be worried about buying slide film in a shop even if that particular film has been on the shelf for several years which is most unlikely. It raises the question of B&W and colour neg film storage. I have seen comments condemning shops, I think it was a branch of Jessops, who didn't go out to the back and presumably to cold storage unit for the film. It does sound as if this is nonsense, given normal turnaround time for film sale, even if neg film has a much shorter shelf life.

    It may also call into question the issue of the need for storage in a freezer of your favourite film that the XYZ manufacturer has just called time on.

    I'd be interested in any studies on neg film longevity at room conditions and yes I do recognise that in the case of HIE( a special case?) freezer storage may be necessary for long term. Or is this also called into question except for say storage for more than X time period.

    Maybe somebody will specify what this X time is?

    Thanks

    pentaxuser

  5. #25

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    Quote Originally Posted by pentaxuser View Post
    Interesting point about the longevity of Fuji slide film at room temp and normal humidity. It clearly means that no-one should be worried about buying slide film in a shop even if that particular film has been on the shelf for several years which is most unlikely. It raises the question of B&W and colour neg film storage. pentaxuser
    Pardon, all the storage data are about PROCESSED film! Unexposed or processed film, both amateur and professional versions, should always be stored refrigerated, but exposed film should be processed as soon as possible.

  6. #26
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    I have stored slide and negative films for nearly 50 years at ambient conditions. Both the Fuji and Kodak products seem to have fared equally well except for E1 and E2 (the first) Ektachrome films.

    I'm not aware that Kodak recommends cool storage for any processed film except for motion picture masters. At least, we never did when I worked on image stability there. So, Heinz, could you please give us a reference to that?

    Thanks.

    BTW, this reference: http://www.kodak.com/global/en/consu...fo/e30/e30.pdf
    says nothing about storing processed materials under refrigeration.

    PE
    Last edited by Photo Engineer; 11-25-2007 at 10:04 AM. Click to view previous post history. Reason: Added reference.

  7. #27

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    Quote Originally Posted by Photo Engineer View Post
    I'm not aware that Kodak recommends cool storage for any processed film except for motion picture masters. At least, we never did when I worked on image stability there. So, Heinz, could you please give us a reference to that?

    Thanks.
    It's the E-4025 datasheet for the Ektachrome E100G/GX films, dated september 2005.

    In times of energy conservation, refrigerated storage of non-perishable items appears as a luxury.

  8. #28
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    The Kodak web site responds with publication E-4024 on G/GX films but no publication E-4025.

    Please see my thread on image stability started in another thread in this forum.

    This may help you understand the situation more clearly.

    PE

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