Sparrow
Mentor
Sorry .. I stand corrected. I should have said damaged by a checked-in luggage scanner
... and so there is no misunderstanding
A hand baggage scanner works a bit like a contact print, radiation is passed through the bag onto a sensor to create a 2D image of the bag's content. I expect these are very low output these days probably much less than the 20 microsieverts used in a chest x-ray, that's around a third of the dose I get each year from living in a stone house, half what you get on a transatlantic flight or eating a dozen bananas
The modern checked-in scanners work by computerised tomography, (those big white things that look a bit like thay thing on Star-gate) and they create a 3D image and if they are anything like the medical ones they will be anything from 50 to 500 times more powerful, say 20 to 60 millisieverts ... I expect the exact details are not available for security reasons.
I became personally aquatinted with ionising radiation last year so I naturally did a bit of research ...
Sparrow
Mentor
Fair enough. Everybody is entitled to their beliefs. But you are denying the research of two established engineering standards organizations, several international equipment manufacturers, and several film companies, all of whon employ many talented engineers. But you ignore them simply because you've never seen it? That kind of denial is amazing... Or your undrstaning of the issues are amazingly minimal.
What I'm finding even more amazing is your denial of the fact that we agree more than we disagree. Curmudgeon doesn't even start to describe that attitude!
Now I'm done. Your a talented photographer but interestingly living in your own little world. But if it works for you then its OK with me.
Well thank you for allowing me to think for myself, and I'm glad you're done as I am becoming tired of your pejorative attitude, and I'm in danger of responding in kind.
I too am content for you to believe what you wish, despite the obvious lack of evidence, and I'm thankful you will be doing it elsewhere in future.
For my part I shall continue to find the dog not barking in the night to be a curious incident.
Gumby
Mentor
It's not perjorative, its frustrated. (and that was a really nice pasive-aggressive way of getting the last dig in. It made me smile!)
I deal with people all day long who don't understand engineering or standardization but prefer to base their vocal opinions on "beliefs" with total disregard for the research that exists. Not to blow my own horn, but with over 125 professional publications in engineering including several national standards that are currently in use, I have a bit of insight into standards and the research behind them. BTW, I also did research for FAA on airport security screening for a few years and intereracted with the equipment manufacturers... so I have a few insights that are not just "beliefs".
Some people simply don't want to accept data when presented to them but insist that they be shown "proof that they can see with their own eyes". I have no problem with that except the absence of proof does not necessarily mean there is an absence of radiation effect in all cases.
Have you ever seen the wind? Have you ever seen a molecule of oxygen? Have you ever seen God (or what ever your deity of choice may be)? Despite never having seen wind or O2 or God many people choose to believe anyway, yet some deny the existence of all three. OK, but that position may be questionable in at least two out of the three examples given. There is scientific and engineering data to prove the existence of wind and oxygen. The existance of God (or any other supernatural diety) is much more open to beliefs... and beliefs alone.
Yes, I say again... the effect of xray radiation from carry-on scanners on film is RARE, extremely rare, and even rarer or nonexistent if one follows the guidelines.
You follow the guidelines and have never had a problem. I follow the guidelines and have never had a problem. Lots of other people followthe guidelines and have never had a problem. None of us have evidence of film damage due to xrays to show you. Why keep asking for it?
But Kodak has published pictures of such damage. The damage from CT was posted earlier in this thread. At one time (but it seems to have been removed) Kodak published pictures of damage due to extreme exposure to carry-on baggage scanner xray. Incidentally, if you never saw it, it looked just like jonmanjiro's images, not the banding that most typically comes from CT. [There is some evidence of banding in the carry-on scanner research but it is much rarer than the overall "haze" and contrast loss kind of damage.]
I agree with every thing you've witten and believe except for one -- that there is never, ever a possiblility of film damage. To be clear: the emphasis is only on the "never, ever" part of the statement.
The only change I propose to your statement is "only in the rare occasion of overexposure to xray radiation that might happen if one disregards the existing guidelines for xray exposure to film."
Engineers have measured some Dmin changes in film with 5 to 10 passes through a scanner. To some that would be noticable. To many it quite possibly will not. For me it likely would not. For you I assume it likely would not. Does that still mean it never happened? They measured more Dmin change with more passes, like 25. To many that would be noticable. They measured even greater Dmin changes with 100 passes. To almost anyone that would be noticable.
The data was done by recognized research agency, was reviewed by peers, and has been published. It's no longer available for free on the internet because it has been archived by IEEE. IEEE, like ISO and the other standards bodies charge for copies. They need to in order to fund their standardization efforts... and they aren't cheap either. Just yesterday I spent about $150 to buy a 40-page ISO standard. The data exists if you really want to know... buy it from IEEE if you didn't have the chance in the past to download it free. I copied pertinent section for you already. You've seen the evidence!
That research (film damage) does not continue too much anymore because it has established engineering data that is known to be stable and not changing. That's a good thing because it means we understand the physics and engineering controls to ensure that film does not get harmed IF ONE FOLLOWS THE KNOWN CONSTRAINTS.
What's worse... especially for film users like you and me... film is old skool, obselete technology, niche, has-been, and whatever other words might be used to indicate that we are int he minority. All of the research money in this area, for the past decade or more, been on research of the effects of radiation and screening technologies relative to digital photography equipemnt and digital storage media. Unfortunately that's the state of the world today and in the future.
That's all I'm saying. Just because it has never happened to you or me is good for us, but doesn't mean it never happens to anyone.
I don't think that is perjorative. I don't think you are perjorative either... just stubborn, perhaps a bit short-sighted on this issue, and seeking the unseekable to prove a point that is simply incorrect. If you find that a perjorative statement, I send apologies along with it.
I'm not the one howling in the wind, BTW... nor is anyone else on this thread. There is no Chicken Little attitude here that often occurs in threads of this type. But it is equally faulty logic to act like the proverbial ostrich with his/her head in the sand.
Gumby
Mentor
The CT machines are quite distinctive looking. From your description it sounds like you did not experience a CT machine, but the more "mundane" kind of xray scanning equipment. I'd guess that based on the images of your film, it got zapped many mroe times than you think it did. Your images are quite similar to those published once-upon-a-time by Kodak to show what extreme exposure to carry-on baggage xray machines looks like.
Out to Lunch
Menteur
Phew...before someone blows a fuse...let me just add that I used to travel to unusual destinations and had my share of troubles: in SE Asia, in Central Africa and in Eastern Europe. At the time, all of the airports had outdated and unserviced x-ray equipment. Today, no problems any longer.
Gumby
Mentor
Ha ha ha...no fuse being popped!
I just tried copy/paste and attach of a PDF page from the report but can't do either. What a shame this site only allows attachments of images. Ha ha ha.
I just tried copy/paste and attach of a PDF page from the report but can't do either. What a shame this site only allows attachments of images. Ha ha ha.
Gumby
Mentor
frank-grumman
Well-known
Gumby,
the only impact on film appears to be tied to 135mm ISO 400 with 50-100 passes. The report on your chart for other film types/ISO's indicates "no observable" effects. So, from your own data, it would appear that for all intents and purposes - inasmuch as I doubt I will ever have a single roll of film undergo 50-100 passes - though who knows - there is no measurable effect on film as a function of X-ray exposure where the machine is assumed to be for carryon luggage. Just askin....
the only impact on film appears to be tied to 135mm ISO 400 with 50-100 passes. The report on your chart for other film types/ISO's indicates "no observable" effects. So, from your own data, it would appear that for all intents and purposes - inasmuch as I doubt I will ever have a single roll of film undergo 50-100 passes - though who knows - there is no measurable effect on film as a function of X-ray exposure where the machine is assumed to be for carryon luggage. Just askin....
Pablito
coco frío
Do you travel much? In my experience you have almost no chance of getting a hand inspection outside USA. I travel all over Europe, Asia & Latin America.
MartinP
Mentor
I read the same pdf extract and it looked to me as though there most definitely is measurable fog from one single pass through the machine on upwards. Read the figures in the column "Average Dmin increase from reference".
'Observable effects' seems to refer to the prints one would be able to make ie. the practical use of the film. A small loss of contrast would not be a noticeable problem (hence the usual recommendations one sees in airports etc.) while irregular banding and density changes would be a noticeable defect. In many places these scanners are used in airports, transport hubs, museums, hotels, restaurants and major shops. It is "easy" to get a dozen checks in a weekend. And my experience agrees with Pablito - you will rarely be allowed a hand-search or chemical swipe check.
Gumby
Mentor
Yes (mostly) and no. Look at the Dmin numbers. They indicate a degradation even when the summarized impact as "no observable effect". And, yes, it is unlikely that one would let their film go through 50 - 100 times! There are other trials they made that indicated affect on 5 - 10. That's how research goes, especially when the sample size is limited.
I showed the data not to prove that noticable xray damage happens. We all seem to agree that it doesn't except for the most extreme (or unlucky) of cases. Remember, these kinds of experiments are probablistic and rely on large amounts of collected data. They are not deterministic in which one or two examples necessarily define a valid trend.
I showed the data to show that changes can be measured... changes that might result in image damage. A lot depends on how picky one is. One could degrade my imges by an awful lot before I'd complain about them being damaged!
p.s. The "knee in the curve" was at 25 passes not 50 for ISO 400, and 10 passes for ISO 1600.
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Gumby
Mentor
The observable effects is the pychophysics assessment of the engineering measurements of Dmin effects caused by x-ray. Psychophysical evaluation is generally the tool used to determine "practical differences" when engineering differences are measured, as you so correctly say.
sevo
Fokutorendaburando
These figures will have been relevant in all-film motion picture days, when that degree of variation in base fog could already make all-optical composites look obviously (and irreparably) flawed. I doubt that many photographers (at least outside a studio doing explicitly composite work) ever worked to similar specifications.
Bob Michaels
nobody special
X-raying film in Cuba is mandatory. There are supposed to be no other options. Yet I am 26 for 26 now in convincing them not to x-ray my film. Sometimes easy, sometimes difficult but always successful. And my Spanish language skills remain very limited.
I am especially concerned about x-ray there since I suspect the guy who maintains the x-ray machines probably drives a '49 Desoto where he has swapped out for a Peugot diesel engine, Chevy transmission, Ford differential, and seats from a Jeep to keep it running.
Bingley
Mentor
I've had no trouble getting hand inspection in Scandinavia or in Vienna. Apparently I don't travel as much as you.
Thardy
Mentor
I was really surprised at how many times my film was scanned when on a trip to Europe a few years ago.
OddE
Recovering GAS addict.
-Sure you can, you just need to ask politely. [Edit: I did NOT mean to imply that you didn't!]
Only last week, I asked for (and got) hand inspections of my Delta 3200 rolls at Copenhagen/Kastrup, Paris/CDG, Oslo/Gardermoen, Frankfurt and Madrid. I've also asked for (and gotten) hand inspections of my ISO3200 film at multiple airports all over the world - the only place I've ever been refused in my request was at Moscow's Sheremetyevo.
At CDG and Frankfurt it was pointed out to me that it really wasn't necessary; I smiled and replied that it probably wasn't, but the film was rather fast (And, hence, more vulnerable) - and I wouldn't be able to tell if any damage had been done until it was too late.
No sweat - after hearing me voice my concern they happily checked my 3200 rolls, while I (just as happily) let the carryon X-ray machine do its thing on my Tri-X.
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Uncle Bill
Well-known
I flew back and forth between NYC LGA and Toronto YYZ with mostly 400 ISO black and white film with no issues at all.
Sparrow
Mentor
You seem to have a real problem with the axiom seeing is believing or as in this case not seeing is disbelieving ... not to mention the concept of I'm done
I have never denied that if it is bombarded enough x-rays will damage film, eventually. What I deny is that anyone is aware of any damaged in the real world, and that you banging on about it is unhelpful to photographers' understanding of that reality, and the use of film in practice
If your quoted diatribe is an example of engineering and scientific method one can see how it leads to this sort of thing LINK, BTW posting a single page of an unattributed report on an unspecified scanner does not constitute proof, it constitutes economy of the truth.
Gumby
Mentor
Oy vay. All of the sudden this quote is starting to make sense: "You’re only young once, but one can always be immature." Grow up.