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Thread: Film base

  1. #31
    Photo Engineer's Avatar
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    Quote Originally Posted by Steve Smith View Post
    I bet that involved some challenges. Our printers complain if we quote a job on anything thinner than 0.004" polyester.


    Steve.
    Steve;

    Not really. The problem was adjusting the film backs to use the thin based film. It was supplied as motion picture and as 120 film both. One used in the capsule mo-pic cameras IIRC and on the ground, and the other was for the Hassie in orbit and on the moon. (oh, I forgot, the moon stuff was all faked. )

    The ground motion picture was such high speed, they needed thin film to get more footage into a standard magazine. I've mentioned before that I saw it jam and spew the camera guts along with sprocket gears all over the test lab.

    The high speed camera had a gear shift type of arrangement to get up to speed so as not to damage the equipment by a sudden jolt of full power. This is also true of high speed coating machines coating polyester. They ramp up to coating speed. This of course, wastes a lot of start up footage so you have to want to coat a lot of film to make a profit and overcome waste. Experiments are done at very low speed to eliminate this problem.

    Also, you must remember that polyester cannot be coated on directly. It needs a corona discharge to pre-condition the film to accept the aqueous gelatin emulsion.

    PE

  2. #32
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    So, the same emulsion can be coated either on acetate or on PET, without any difference?
    Aurelien, Analog Photographer

    the analog place to be

  3. #33
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    Just about.

    PE

  4. #34

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    Hi all, I'm reviving this thread because it discusses vinegar syndrome, the subject of my post. The admins can move it if necessary to the appropriate place.

    I'm currently scanning some colour negatives that my father exposed in the 1960s and 1970s for retouching and archiving. Some of these (too many!) are cut into individual negatives - as seemed to be the norm back then. On these individual negs, there's a distinct line of tobacco-brown 'stain' (in positive) along the edges of the image area adjacent to the cut edges. The film is 120 format, Kodacolor X and Kodacolor II, and the former appear more affected by this (because they're older, or different process?). These have been stored in mostly glassine neg bags inside paper envelopes in UK domestic conditions, not particularly humid.

    I wonder whether this could be the starting point of vinegar syndrome deterioration, or is it something else - environmental contamination perhaps?

    Here's an example; note the discolouration along the top edge: http://s20.postimage.org/4okhy9afh/abington4.jpg

    Cheers,
    kevs
    Last edited by kevs; 03-17-2013 at 05:23 AM. Click to view previous post history. Reason: add url
    testing...

  5. #35
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    This is not, in any way, related to "vinegar smell" or "vinegar syndrome".

    It may be fungus attack or it may just be that the stabilizer is running out of potency.

    A dip in old style Formalin Stabilizer and then drying might halt the process. OTOH, it may just be heat induced dye fade.

    BTW, the example is rather hard to see.

    PE

  6. #36
    Mustafa Umut Sarac's Avatar
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    oh, I forgot, the moon stuff was all faked.
    I swear on Bible , I saw an palm tree at moon shots , all was taken in Hawaii not at moon !

  7. #37

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    Quote Originally Posted by Photo Engineer View Post
    This is not, in any way, related to "vinegar smell" or "vinegar syndrome".

    It may be fungus attack or it may just be that the stabilizer is running out of potency.

    A dip in old style Formalin Stabilizer and then drying might halt the process. OTOH, it may just be heat induced dye fade.

    BTW, the example is rather hard to see.

    PE
    Thanks P.E. It's good to know it's not vinegar syndrome anyway. I wondered whether the base was starting to deteriorate considering their age. I haven't noticed any vinegar smell around them. There's no sign of fungus and I don't think heat is very likely since they've been stored in a dry, dark and mostly cool bedroom drawer since about 1970. However I can't comment upon their early life since I wasn't around then, and it's likely they've been exposed to fumes from woodwork, clothing, toiletries and other things that have been stored alongside them.

    Here's a larger example from a different neg, showing just the affected area and surround for context: http://s20.postimage.org/ue4bjl79n/abington3.jpg. This is the 56mm slice across the film's width, exposed in a 6cm x 4.5cm (16-on-120) camera.

    Still, nothing lasts forever, and when I'm dead I doubt anyone will care about them anyway. :-D

    Thanks for your time and effort here, it's most appreciated. :-)
    Cheers,
    kevs
    Last edited by kevs; 03-17-2013 at 08:39 PM. Click to view previous post history. Reason: larger image uploaded
    testing...

  8. #38
    lxdude's Avatar
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    Quote Originally Posted by Mustafa Umut Sarac View Post
    I swear on Bible , I saw an palm tree at moon shots , all was taken in Hawaii not at moon !
    You assume there are no palm trees on the moon. If we've never been there, how do we know?
    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.

  9. #39
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    Kevs;

    If on the positive, you see a reddish yellow image, this means that those dyes are becoming absent in the original. These are affected by heat and humidity and the magenta, in particular, is affected by the lack of stabilizer.

    PE

  10. #40

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    Quote Originally Posted by Photo Engineer View Post
    Kevs;

    If on the positive, you see a reddish yellow image, this means that those dyes are becoming absent in the original. These are affected by heat and humidity and the magenta, in particular, is affected by the lack of stabilizer.

    PE
    Thank you for the info P.E., at least I know what's going on. I'll bear it in mind when deciding how to store the collection, though I'm not sure i want to start soaking 40 year old negatives in anything. :-)

    Cheers,
    kevs
    testing...

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