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.
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