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Thread: ULF film flatness idea

  1. #11

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    Re: ULF film flatness idea

    The camera that the bellows came out of was a graphic arts camera with a v. heavy vacuum back. I'd do almost anything to avoid having to run a noisy vacuum pump---I might could live with a quite one and it wouldn't solve the use of "miniature" film in giant film holders which might be nice for tests. I suspect that if I build this camera I'm going to have to make my own film to afford to be able to use it and I'm originally trained as a chemist and have wanted to try this for years. If so, I might just put the "film" (emulsion) on plexiglas, which is not as rigid as glass might be better, if only because it wouldn't have waves, just a single dip, or at least I think so.

    Do these low tack adhesives remain low tack for a long time? Is it hard to get the residue off? When I first started this LF game I taped bits of 35 mm film into 4x5 holders just to have something to try and the electrical tape was a poor choice---it lifted the paint off the septa of the holders, it left gobs of adhesive behind. Yuck.

    I believe Drew is right that for crucial scientific applications (astronomy surveys) the negative of choice was something a lot like tech pan on glass since you couldn't know for sure where your camera would point and sag would mess up measurements. I'm pretty sure that the original holders for glass plates did use 8x10 pieces of glass and when those were retrofitted or additionally fitted with metal inserts for thinner flexible film the film size had to be reduced slightly to fit in the metal holders and ever since 8x10 film hasn't been actually quite 8x10. Somewhere I have some non-modern standard ?Kodak? 8x10 holders like that. I'm not sure where you get glass or plexiglas thin enough but I'd have to dig a while to find them to measure things, sorry.

    I don't know what the toxicity would be from spray adhesives. Many things, potentially. I've used high strength spray adhesive for affixing formica to telescope bearing surfaces but I always spray it in the driveway well away from the cars. These days the propellant is likely butane (or similar) which is what Bic lighters run on. Safe from explosion propellants like freon being disallowed. More than a few wet plate practitioners died in fires, ether and ethanol and nitrocellulose all being either motor fuels, or components of smokeless gunpowder, this in an era when a darkroom light was probably red-glassed kerosene lantern. I don't want any of us to suffer that kind of fate or any toxicity. I'd like to try some wet plate and dags for bragging rights, but I'm not really in a hurry and don't want to make it an ongoing thing. Gelatin emulsions offer a lot of advantages.

  2. #12

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    Re: ULF film flatness idea

    Another crazy question then, what about roll film for ULF/LF? That would require a vacuum back as adhesives would stop the film motion. The military used LF or ULF film rolls for aerial reconnaissance. I doubt that film is still available to the public if it ever was. So, first I'd have to figure out how to make film. To get 12 exposures of 20" squares would require 20 feet of film (or more with a smidgen of leader and space between frames). I don't foresee having a space that big in which to make the film... I wonder if something like that could be made light enough to compete with film holders for weight. With the right darkroom set up the individual frames could either be cut apart before or after processing. Blackout cloth like for curtains could be used for backing, film registration markings would have to be drawn/stenciled on the back.

  3. #13
    Vaughn's Avatar
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    Re: ULF film flatness idea

    The Polaroid 20x24 cameras used rolls. The cameras are still out there somewhere.

    PS...they brought one out special to Sante Fe, NM (outside), but the change in humidity made it unusable due to light leaks.
    "Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China

  4. #14
    Tin Can's Avatar
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    Re: ULF film flatness idea

    Many roll film cameras use a spring loaded pressure plate

    Some used vacuum

    Rolls of paper emulsion ready made are still sold

    Thought experimentation is not free

    Time eats life
    Images vastly preferred

    not game trying to


    focus


    In Time

  5. #15

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    Re: ULF film flatness idea

    Quote Originally Posted by Tin Can View Post
    Many roll film cameras use a spring loaded pressure plate

    Some used vacuum

    Rolls of paper emulsion ready made are still sold

    Thought experimentation is not free

    Time eats life
    I'd seen that Ilford makes rolls of printing paper still. That won't work for UV contact printing.

    Life does get consumed with darting about chasing lots of ideas, but sometimes that's exactly what makes life worthwhile, no? The way the rest of the photographic world thinks, all of us LF enthusiasts are nuts.

  6. #16
    Zebra
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    Re: ULF film flatness idea

    Quote Originally Posted by Drew Wiley View Post
    That "dern evidence" has been well known for generations. It's been an obvious problem ever since flat glass or metal plates were no longer used. Later a little tab of ATG tape was put behind the middle of the film - not the best idea but it halfway worked. Vac holders in one fashion or another are nothing new. And if you want serious evidence, find me a graphics copy camera anywhere that didn't require a vac easel - the real ULF machines!
    The bigger the film, the more the overall problem. Sinar offered adhesive holders in 5x7 and 8x10; and I think that right around 5x7 it starts becoming a noticeable issue with moderate enlargements. For technical or scientific projects, even 4x5 should be controlled. For ordinary contact printing applications, all depends. ULF film is generally contact printed, but mere perceived sharpness is not all that is in play here. I once saw a 16X20 AA print with a distinct sag in the ocean horizon.
    Ansel seemed to have survived the catastrophe just fine I would say. As I said earlier we all have to make decisions for our photography for ourselves. For my photography and the way I contact print on art paper with hand coated Pt/Pd salts I'm much more concerned with creating a photograph that is compositionally sound, creates atmosphere and mood, and conveys something beyond technical proficiency. The trick to your point Drew as I see it anyway is the technical proficiency can't detract from the above goals. If a lack of film flatness does just that--detract then it should be addressed. I suppose that is all in the eye of the beholder of course but as of now I've never had an issue with my 10 x 12's, 7 x 17's or my 20 x 24's. Again that is for me and the goals I have set for myself. Each to their own as it should be I suppose when you consider the overwhelming majority of us on this forum do this much more for ourselves than for any true impact or notoriety we might enjoy through the pursuit. As such we have to please our own sense of balance for technical proficiency and artistic expression.

  7. #17

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    Re: ULF film flatness idea

    Other than the times i have aimed my 8x10 almost straight down, I have never had a problem with 8x10, 5x12 or 7x17. Why? I don't know, probably just dumb luck.

  8. #18
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    Re: ULF film flatness idea

    I have had issues with 8x10 many times...long exposures under the redwoods...30 secs to several minutes long. It has been mostly the film not sitting square in the holder, then falling square during the exposure. Usually one corner will be relatively sharp, the rest getting worse towards the opposite corner (which moved the most). Cured by a gentle thump on the bottom on the holder with my hand before loading into the camera. And sometimes a negative will just pop in the holder for reasons of its own. Going from warm/dry to cold/moist once the darkslide is removed, perhaps.

    My 11x14 holders tend to have much heftier rails for the film to be held by than 8x10...probably helps some.
    "Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China

  9. #19
    Drew Wiley
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    Re: ULF film flatness idea

    Film thickness varies somewhat overall. Film base stiffness is another factor. The worst scenario for me was when color sheet films were nearly all on floppy triacetate base for over well a decade. That wasn't dimensionally stable either, causing real headaches with mask registration. But that was also right around the time I shifted from 4x5 to mainly 8x10 shooting for quite awhile, and soon began using adhesive holders in relation to color film. All my black and white films had more stable polyester base, however, just like most do today, and I don't print b&w larger than 20X24 anyway - less than 3X enlargement from 8x10. With color I'd frequently go up to 30X430 inch prints, so had to be more nitpicky in that case with flatness issues in the holder. Once in awhile in cold damp weather I'd adopt an adhesive holder for b&w 8x10 film due to the potential risk of what Vaughn just described, though temp related popping has actually happened to me only once.

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