Author Topic: Radiation and photographic film  (Read 13494 times)

Offline Allan F

  • Jupiter
  • ***
  • Posts: 896
Radiation and photographic film
« on: May 22, 2013, 11:04:34 AM »
I've been wondering, how much the radiation and the photographic film interacted on the Apollo travels. As I see it, there are 3 distinct environments, which need to be taken into account:

1: Film in magazines, in boxes, in the LM, in the Van Allen Belts
2: Film in magazines, in boxes, in the LM, in free space or on the moon
3: Film in magazines, on the surface of the moon

Is there any way to compare the radioactive dose absorbed by the film, to the amount of light energy needed to darken the film by, say, 50%?

In order to do this, the effects of various types of radiation, and it's interaction with the materials between the film and the various environments need to be understood, and the time in each environment need to be understood.

For simplicity's sake, I'll assume each photographic magazine was outside the LM on the surface for the endurance of a moonwalk, about 8 hours, the traverse of the Van Allen Belts were 1 hour in each direction, and the total of free space and lunar surface ops were 12 days 1 hour. That's the duration for Apollo 17, btw.

What I need is an understanding of the particle-to-x-ray conversion and the attenuation by the various materials between space and film.

Edit: My initial assesment, based on nothing but my years spent as a photo-amateur, makes me believe, that the film used, protected as it were, would survive several moon trips without being significantly damaged.
« Last Edit: May 22, 2013, 11:19:35 AM by Allan F »
Well, it is like this: The truth doesn't need insults. Insults are the refuge of a darkened mind, a mind that refuses to open and see. Foul language can't outcompete knowledge. And knowledge is the result of education. Education is the result of the wish to know more, not less.

Offline ChrLz

  • Earth
  • ***
  • Posts: 241
Re: Radiation and photographic film
« Reply #1 on: May 25, 2013, 08:17:46 AM »
I've been wondering, how much the radiation and the photographic film interacted on the Apollo travels.
Why?  I'm not trying to be smart or suggest you are a secret Apollo Denier, but I'm interested..

Maybe someone else here (JayW?) can elaborate further, and maybe there is a way to do this meaningfully, but I doubt it and I'm going to take a slightly contrary view..

Quote
As I see it, there are 3 distinct environments, which need to be taken into account:
1: Film in magazines, in boxes, in the LM, in the Van Allen Belts
2: Film in magazines, in boxes, in the LM, in free space or on the moon
3: Film in magazines, on the surface of the moon
Well, yes, I guess that's a starting point, but.. even that is over-simplifying it - what about when the cameras were in shadow?  Astronaut shadow versus LM shadow?  Near ground or at chest height?  Etc, etc..

Quote
Is there any way to compare the radioactive dose absorbed by the film, to the amount of light energy needed to darken the film by, say, 50%?
Effectively impossible, I'd guess.  Light is, after all, a small subset of the total radiation..  and you have radiation both above and below the visible light range and all of it interacts differently with the camera body itself and then the multiple photosensitive film layers and the base emulsion, and of course then there's the film which is still wound prior to being exposed versus the frames at or near the light chamber and the interactions with the backplate and the reseau plates, versus that which is wound onto the takeup spool on the other side of the cartridge...  There's also the fact that the chemical nature of the film has changed *after* it is exposed, so you'd havta do it twice...

Quote
In order to do this, the effects of various types of radiation, and it's interaction with the materials between the film and the various environments need to be understood, and the time in each environment need to be understood.
No, I'd argue that they actually don't need to be understood in the sense of some sort of accurate theoretical evaluation..  What I mean is, rather than agonise yourself to a possible early grave by trying to work out some meaningful way to come up with a number that would probably be wildly inaccurate due to the enormous complexity and variability of the situation, why not use a basic understanding and a ballpark idea, and then just take the cameras up into orbit and try them out and see what happens..?  (Phew - I knew I shouldn't have held my breath as I typed that sentence..:D)  Which is pretty much what they did.  After all, we have a fairly good understanding of how film is affected down here on earth in hot/cold environments, at high altitudes, over long periods.  We also know how the radiation varies once you get into orbit and beyond, and most of this was pretty well tested and understood (eg Gemini) before A11 made it for the real thing.

Quote
For simplicity's sake..
I don't think any attempt to do this in that fashion would be remotely 'simple'..  You'll find light sensitivity curves for the film easily, and then maybe susceptibility to xray (eg airport xray) type radiation, but extended radiation sensitivity?  That would probably involve materials scientists with very sophisticated and expensive equipment, rather than Kodak or Hasselblad..  So why not just take the cameras up on missions and try them out and look carefully at the results?  Which is what they did.

Frankly, it just wasn't that much of an issue, in the same way that radiation in general wasn't a big deal for these short missions (barring intense solar activity..)...

Quote
Edit: My initial assesment, based on nothing but my years spent as a photo-amateur, makes me believe, that the film used, protected as it were, would survive several moon trips without being significantly damaged.
While I agree and the evidence suggests you are right, earthly experience doesn't count for much in space.  And in this case, I don't think there is/was any substitute for simply testing it out in the actual environment..

Offline Allan F

  • Jupiter
  • ***
  • Posts: 896
Re: Radiation and photographic film
« Reply #2 on: May 25, 2013, 10:23:40 AM »
The reason for my question is the simple, that on another forum, I came up against a person, who claimed all the apollo photos are bogus, because radiation in space would destroy the film.

Obviously, it didn't. Now, for my own amusement, and in order to have my gun loaded for the next zombie attack, I wondered, if someone here had the info I'm seeking.

Please, don't wonder about my opinion about Apollo. There is no doubt, in my mind or in my words, that the historical account is accurate, to within the limits of human understanding. Some errors, like misnumbered photos may have snuck in, most errors are in the post-processing, like overdubbing video with wrong sound. And that's the fault of the tv-company, doing the documentary you view.

Edit: I did a rough calculation, based on some wildly inaccurate assumptions, that the amount of radiation received by the film (and absorbed) was equivalent to 1/4000 of the energy needed to blacken the film by 50%. I won't even post my calculations, because I could be a factor 100 wrong in both directions.
« Last Edit: May 25, 2013, 10:31:43 AM by Allan F »
Well, it is like this: The truth doesn't need insults. Insults are the refuge of a darkened mind, a mind that refuses to open and see. Foul language can't outcompete knowledge. And knowledge is the result of education. Education is the result of the wish to know more, not less.

Offline ChrLz

  • Earth
  • ***
  • Posts: 241
Re: Radiation and photographic film
« Reply #3 on: May 25, 2013, 10:55:55 AM »
The reason for my question is the simple, that on another forum, I came up against a person, who claimed all the apollo photos are bogus, because radiation in space would destroy the film.
Ah, I see...  May I suggest that you offer to help him work through this *properly*..  First, as he clearly knows about this stuff :D, ask for the types/wavelengths and intensities of radiation that would exist on the Moon to destroy the film, and where he got his figures.  If he doesn't have them to hand, you could suggest some ways he could research those figures, while at the same time expressing extreme puzzlement as to:
1. Why he didn't do that first..
2. In the absence of such numbers, what on earthmoon he based his 'opinion' on (other than his deep desire to believe in a conspiracy..)

I don't think the conversation will get much further..

Offline Allan F

  • Jupiter
  • ***
  • Posts: 896
Re: Radiation and photographic film
« Reply #4 on: May 25, 2013, 11:11:29 AM »
That's what I did - and it has been dragging on for about 2 weeks now. Everytime I ask a pertinent question, I get foul language in return.

Example: I asked: "AND you still have to quantify the amount of your particles - one particle on the entire journey won't cause enough radiation to make a spot on even unshielded film. You need to tell us the number of particles in a cubic centimeter"

and got: "The number of particles is E = MC2 to the 33rd power x the number of Freemasons on the US Fed board by birth, divided by their greed & contempt for constitutional normalities, then multiplied by the collective debt of the US Taxpayer over their US Federal Deficit after the entire NASA budget since the faked Apollo landings was added in triplicate. Secondary radiation from high-energy particles from old nova make your Venus photo as impossible as a magic bullet going to Uranus via Dallas Texas."

Earlier, he made some sense, but not much. I'll spare you for his anatomical references,

Edit: Here's the exchange, if you have the time to get a good laugh:
« Last Edit: May 25, 2013, 11:58:25 AM by Allan F »
Well, it is like this: The truth doesn't need insults. Insults are the refuge of a darkened mind, a mind that refuses to open and see. Foul language can't outcompete knowledge. And knowledge is the result of education. Education is the result of the wish to know more, not less.

Offline Trebor

  • Earth
  • ***
  • Posts: 199
Re: Radiation and photographic film
« Reply #5 on: May 25, 2013, 01:39:43 PM »
This might be of use :
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4324793&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4324793

I have the full paper and can email it if you are unable to get it from there.

Offline Allan F

  • Jupiter
  • ***
  • Posts: 896
Re: Radiation and photographic film
« Reply #6 on: May 26, 2013, 12:43:38 AM »
Yes, please, that would be very helpful. Just take my usename, remove the space, and add (at)galnet.dk
Well, it is like this: The truth doesn't need insults. Insults are the refuge of a darkened mind, a mind that refuses to open and see. Foul language can't outcompete knowledge. And knowledge is the result of education. Education is the result of the wish to know more, not less.

Offline Allan F

  • Jupiter
  • ***
  • Posts: 896
Re: Radiation and photographic film
« Reply #7 on: May 26, 2013, 06:08:31 PM »
What missions were launched to measure the radiation in space, after Explorer 1 did the initial discovery? Were the particle radiation quantified and how? I'm sure NASA didn't send men beyond LEO without actually having done extensive research first.

Well, it is like this: The truth doesn't need insults. Insults are the refuge of a darkened mind, a mind that refuses to open and see. Foul language can't outcompete knowledge. And knowledge is the result of education. Education is the result of the wish to know more, not less.

Offline gwiz

  • Mars
  • ***
  • Posts: 331
Re: Radiation and photographic film
« Reply #8 on: May 27, 2013, 06:39:24 AM »
What missions were launched to measure the radiation in space, after Explorer 1 did the initial discovery? Were the particle radiation quantified and how? I'm sure NASA didn't send men beyond LEO without actually having done extensive research first.


Dozens of missions, lots of the Pioneer and Explorer series with the usual variety of radiation sensors, right up to Apollo 4 and 6 with dosimeters to get the crew exposure inside the CM.
Multiple exclamation marks are a sure sign of a diseased mind - Terry Pratchett
...the ascent module ... took off like a rocket - Moon Man

Offline Noldi400

  • Jupiter
  • ***
  • Posts: 627
Re: Radiation and photographic film
« Reply #9 on: May 27, 2013, 08:10:52 PM »
What missions were launched to measure the radiation in space, after Explorer 1 did the initial discovery? Were the particle radiation quantified and how? I'm sure NASA didn't send men beyond LEO without actually having done extensive research first.
Isn't it always amazing how some people (not you, Allan F) interpret "concern" as being synonymous with "insurmountable obstacle"?

Edit: Having looked at that exchange now, IMO you're wasting your time.  He's either just being an obvious troll or has bought into notions so far afield they make moon hoax belief seem like a matter of taste.

Besides, if such a "Bell" existed, and people traveled inside it, the shielding they would require for the radiation it supposedly emitted would make anything found in space barely a second thought.
« Last Edit: May 27, 2013, 08:41:16 PM by Noldi400 »
"The sane understand that human beings are incapable of sustaining conspiracies on a grand scale, because some of our most defining qualities as a species are... a tendency to panic, and an inability to keep our mouths shut." - Dean Koontz

Offline Allan F

  • Jupiter
  • ***
  • Posts: 896
Re: Radiation and photographic film
« Reply #10 on: May 27, 2013, 08:19:14 PM »
"But that's difficult!"
"Yes, come back tomorrow!"

It is their inability or unwilling to acknowledge there are smarter and better people than themselves.

Edit: I know I'm above average (scored 156 at mensa, but didn't join), but I still have to look up to a lot of smarter people.
« Last Edit: May 27, 2013, 08:23:47 PM by Allan F »
Well, it is like this: The truth doesn't need insults. Insults are the refuge of a darkened mind, a mind that refuses to open and see. Foul language can't outcompete knowledge. And knowledge is the result of education. Education is the result of the wish to know more, not less.

Offline Kiwi

  • Mars
  • ***
  • Posts: 431
Re: Radiation and photographic film
« Reply #11 on: May 28, 2013, 11:03:15 AM »
I was a professional photographer from the mid 70s to 1989 and a dedicated amateur before that, and examined many photographs for clients of my shop and studio.

There is one thing in some of the online lunar surface photos that intrigues me because I've not seen it in any other transparencies and have not seen any discussion about it, so I wonder if it could be radiation:-- Tiny blue dots.

They could even be artifacts of the scanning process, but being circular, I have to wonder if they are indeed in the original transparencies.  However, they are tiny and difficult to find, so if they are caused by radiation the effect is negligible.

AS11-40-5906 has one of the dots, on the far right edge, in the black sky just above the horizon.  Further down, to the right of the shadows of Buzz's PLSS and right elbow there are three white dots and a pale blue one.  However, there is a lot of glass on the moon so they could just be specular highlights caused by reflections of the sun.
http://www.hq.nasa.gov/alsj/a11/AS11-40-5906HR.jpg

Three more white dots can be seen below and to the left of Jack Schmitt's boots in AS17-40-22158
http://www.hq.nasa.gov/alsj/a17/AS17-145-22158HR.jpg
« Last Edit: May 28, 2013, 11:17:10 AM by Kiwi »
Don't criticize what you can't understand. — Bob Dylan, “The Times They Are A-Changin'” (1963)
Some people think they are thinking when they are really rearranging their prejudices and superstitions. — Edward R. Murrow (1908–65)

Offline Allan F

  • Jupiter
  • ***
  • Posts: 896
Re: Radiation and photographic film
« Reply #12 on: May 28, 2013, 11:26:19 AM »
Well, a lot of the photograph available are second and sometimes even third generation prints. A lot of opportunities for dust to creep in. Just think about the famous "c"-rock photo - a small piece of dust in the scan/copy process, and off they go.

I'm not sure, but I think an artefact that big (visible) is more likely to be dust, than radiation. The radiation damage should be uniformly distributed all over the film, looking like a slight darkening of the original negative.

Edit: What would be interesting, would be to see consecutive photos from the same roll, and the same copying process.

Edit2: Remember, the energy in ONE single x-ray photon or gamma photon is microscopic, when looking at macroscopic objects. And the photons aren't in any way focused, but very scattered. If it was a radiation event, it would most likely come from a radioactive contaminant, inside the film magazine. And I don't think that's likely.
« Last Edit: May 28, 2013, 11:34:08 AM by Allan F »
Well, it is like this: The truth doesn't need insults. Insults are the refuge of a darkened mind, a mind that refuses to open and see. Foul language can't outcompete knowledge. And knowledge is the result of education. Education is the result of the wish to know more, not less.

Offline ChrLz

  • Earth
  • ***
  • Posts: 241
Re: Radiation and photographic film
« Reply #13 on: May 28, 2013, 06:00:17 PM »
There was a discussion about the blue specks some time ago, and I'm pretty sure that the consensus was that they were simply scratches and other film defects/damage - from lunar regolith particles and possibly even static sparks - when you scratch Ektachrome lightly, you tend to reveal the blue layer iirc..   I'll see if I can find it but not right now, have other stuff I need to do....

Offline Allan F

  • Jupiter
  • ***
  • Posts: 896
Re: Radiation and photographic film
« Reply #14 on: May 28, 2013, 06:40:29 PM »
The hasselblad cameras were modified to deal with the static charge between the film and the camera. The scratch idea seems like a good one. The emulsion is very sensitive, especially when it's being processed, and is wet.
Well, it is like this: The truth doesn't need insults. Insults are the refuge of a darkened mind, a mind that refuses to open and see. Foul language can't outcompete knowledge. And knowledge is the result of education. Education is the result of the wish to know more, not less.