Apollo Discussions > The Hoax Theory
Film Outgassing
benparry:
Afternoon All. Another debate on FB haha.
Even though i am a half decent photographer :) i have never used film. I have been challenged by a hoaxer that the film would have outgassed in the vaccum which would have rendered it either unusable or certainly not possible to take the great photos that we see.
What can i go back to him with please. This is above my head
bknight:
The film used was similar to the film used in the U2s high altitude special film that you can't buy at Walmart. The Lunar probe Lunar Orbiter used a FILM to capture moon images, and that was IIRC the same film used in Apollo missions. You won't switch a HB because he "knows" the truth on what he proposes, but you are actually correct.
benparry:
--- Quote from: bknight on October 01, 2024, 09:00:29 AM ---The film used was similar to the film used in the U2s high altitude special film that you can't buy at Walmart. The Lunar probe Lunar Orbiter used a FILM to capture moon images, and that was IIRC the same film used in Apollo missions. You won't switch a HB because he "knows" the truth on what he proposes, but you are actually correct.
--- End quote ---
Oh i know that haha
Would the film outgas and would this cause an issue
Allan F:
The active part is silver bromide crystals, which isn't a gas by any stretch of the imagination. It is a colloid (like a dried slurry) of AgBr crystals and a gelatine medium, bonded to a backing of plastic. Since it is a DRY colloid, there is no water that can evaporate, not really anything that will react in vacuum. The Silver Bromide crystals are contained in the gelatin, and can't go anywhere either. I really don't see any significant "outgassing" even after prolonged exposure to vacuum. Please ask them to clarify what exacty it is that would "outgas"
JayUtah:
Everything outgasses in vacuum.
The way Estar film bases handle this is to be very thin (say, 0.0025 in) so that all the outgassing that's going to happen happens early. It's not as if things outgas indefinitely. It's a half-life phenomenon. Estar is basically polyethylene terephthalate, commonly referred to as PET. It is used in practically every commercial sector (e.g., "plastic" soft drink bottles) and its properties are well known. Notice how none of the zillions of properly educated materials scientists are questioning the Apollo photography.
The Kodak SO-135 and SO-136 emulsion types were specifically hardened to expand their useful temperature range and further tweaked to increase evaporation and outgassing rates. Again, you can't stop the emulsion from absorbing water and then outgassing it later. The point is to have that happen very quickly, so that you aren't bothered by it later. Keep in mind that the processing of these films involved aqueous solutions. Drying time was a factor. These emulsions are specially intended for high-altitude and vacuum use, and are approximately half as thick as the ordinary emulsions on consumer Ektachrome. All the outgassing that's going to happen will happen early.
The lunar surface magazines were kept in the LM's MESA, exposed to vacuum during the entire outbound journey. They were not gas tight. By the time the astronaut removes the dark slide and attaches the magazine, there's simply nothing left to outgas.
Also, it's not clear by what mechanism outgassing is claimed to ruin photography. It's a non sequitur. Yes, things outgas. Why would this result in photography not being as shown?
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