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]

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.

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?

[Peter B]

Everything outgasses in vacuum...

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?

Speaking as a non-photographer with a little knowledge of chemistry and photography, my assumption has been that the hoax believers are claiming that (a) the emulsion is a liquid, and that (b) in a vacuum the liquid sublimates (the "outgassing"), leaving the light-sensitive chemicals nothing to hold them onto the film.

I'm aware of my ignorance of the topic, but it's not something I've bothered to learn much about.

[benparry]

Unfortunately another HB bites the dust. Blocked again. I would love to know how many times that has happened haha. Cheers guys

[jfb]

I know they had to change out the lubricants in the cameras because they were worried about how they'd behave in a vacuum (mostly by vaporizing/outgassing and depositing schmutz on the lenses), but I've never heard any concerns about the film.  This is a new one to me.   

Plastics, including film, outgas at normal atmospheric pressures ("new car smell" is basically outgassing vinyl).  If it were going to be a problem for film, it'd be a problem on the ground as well as in space. 

Now I'm really curious what the exact claims are.  We could test those claims relatively easily -- buy a batch of Ektachrome, stick half of it in a vacuum chamber for a few days (lab grade vacuum isn't a hard vacuum like on the lunar surface, but it should be good enough to encourage rapid outgassing), shoot and process it, compare results. 

[Peter B]

...Now I'm really curious what the exact claims are...

LOL! Do hoax believers ever make "exact" claims? It wouldn't surprise me that the claim is just "outgassing!", like "radiation!" or "destroyed the technology!".

[onebigmonkey]

The source of the claim is largely the 'Apollo Detectives'. They've insisted that the film in the Lunar Orbiter needed to be pressurised in order to protect it, when in fact mininal pressure of 1-2 psi of Nitrogen was used to make sure the fllm stayed where it was supposed to during exposure.

They found a tame physicist with access to a vacuum, and duly exposed off the shelf film to vacuum several times. The end result was: perfectly acceptable photographs that could (in the hands of a skillful developer) have easily been colour balanced correctly. Nautrally they claimed victory, saying the film was ruined, but it really wasn't.

There's an Aulis article about it.

[Allan F]

Was it that experiment where they put film in an ordinary oven, and destroyed it, claiming the same temperature would be relevant on the moon?

[bknight]

I don't know if it the same as you are asking, but I have a vague remembrance of a film where either Percy or Allen demonstrated the film in an oven and later a film in a microwave oven indicating that filming would be impossible during Apollo.  This was maybe 10years ago, that is why I called it a vague remembrance.

[TimberWolfAu]

The source of the claim is largely the 'Apollo Detectives'. They've insisted that the film in the Lunar Orbiter needed to be pressurised in order to protect it, when in fact mininal pressure of 1-2 psi of Nitrogen was used to make sure the fllm stayed where it was supposed to during exposure.

They found a tame physicist with access to a vacuum, and duly exposed off the shelf film to vacuum several times. The end result was: perfectly acceptable photographs that could (in the hands of a skillful developer) have easily been colour balanced correctly. Nautrally they claimed victory, saying the film was ruined, but it really wasn't.

There's an Aulis article about it.

Didn't the guy doing the vacuum tests also come to the conclusion that it wasn't the vacuum itself that did the main damage but the repeated cycling in and out of a vacuum?

And from what I can recall, the original Lunar Orbiter also developed the photos in lunar orbit, scanned the result, and transmitted the picture back to Earth. Pretty sure you would need a pressurised vessel for that. Fortunately, Apollo waited until they got back to Earth, and left the developing to professional like Terry Slezak (first non astronaut to be 'contaminated' by lunar dust).