Airport x-rays, film, and metal!

[BrianShaw]

Reportedly the checked luggage scanners are higher power and I deliberately left a blank roll of Ektar in my checked luggage for a couple of flights to test that.

For the CT scanners in use in most of the world it is not really a matter of "reportedly" but more of IF USED. The modern CT scanners are two-stage. First scan is a regular x-ray about the same as that used for the carryon bags. If there is reason for additional scanning, the CT is used and that is what ruins the film. So film in carryon bags is OK, but film in checked baggage is a crap shoot.

[Athiril]

iirc you need about 5+ passes to have visible xray fogging start to show up from normal carry on scanners from film. Each pass obviously does damage, otherwise no amount of passes would ever affect it.

As for checked baggage scan.. every roll with a sine wave on it I've gotten from others has gone through checked baggage.

[BrianShaw]

iirc you need about 5+ passes to have visible xray fogging start to show up from normal carry on scanners from film. Each pass obviously does damage, otherwise no amount of passes would ever affect it.

More than that, I think. If I recall the research correctly, 5 passes results in the most miniscule, barely measurable effect on fast film. I think the number for visually noticable fogging was closer to 14 passes.

[polyglot]

Well, I got nothing visible at all on Portra 400 after 14 passes. Maybe you could measure it with a densitometer compared to a control roll but I cannot spot any difference in a side-by-side comparison.

[Stephen Schoof]

Thanks for the input, everyone. I was fairly convinced there was nothing to worry about, then I read about the 'metal' aspect, and got to wondering. Now I again feel better about it all. I'll report the final outcome next week.

[BrianShaw]

Well, I got nothing visible at all on Portra 400 after 14 passes. Maybe you could measure it with a densitometer compared to a control roll but I cannot spot any difference in a side-by-side comparison.

I looked at the data again and found that my recollection wasn't too far off, but here's a little mroe that supports your experience. For 400 ASA Color Neg there was measureable but insignificant effects at 5 to 10 passes. Noticable effects were observed only at 25 passes or more. For 800 ASA noticable effects at 10 passes or more.

For most people this is well within the realm of "not a problem". I know for me it has never been, either.

[heterolysis]

For my travel through Canada and the US, this has never been an issue with films 50-800 ISO.

I did however get held up for ~15min once when I gave them my a12 film back and told them they couldn't open it!

[polyglot]

I looked at the data again and found that my recollection wasn't too far off, but here's a little mroe that supports your experience. For 400 ASA Color Neg there was measureable but insignificant effects at 5 to 10 passes. Noticable effects were observed only at 25 passes or more. For 800 ASA noticable effects at 10 passes or more.

For most people this is well within the realm of "not a problem". I know for me it has never been, either.

I would ask when that testing was done. Imaging xray sensors are far more sensitive now than even one decade ago and the flux is much much lower.

[BrianShaw]

The data is actually a bit old. It was from when they established the FAA reccomendations. I would assume that if done again the data would show even more film-safeness (if that is a word) with the newer equipment. Unfortunately I've lost my ties to the scanner manufacturers otherwise I'd ask them... but I think you might be correct about lower dosage levels. I know when I was working those issues the focus was on post-processing techniques to eliminate the need to "re-zap" items yet get better discrimination of contraband. At one time the manufacturers all had their specs online so I suppose with a little effort that could be verified rather easily.

[tim elder]

I haven't had a problem with running roll film through security in the US and Western and Eastern Europe. I do carry my film separately from my camera bag because there have been times when they have been a little bit more inquisitive of the camera bag and have done multiple passes of it, or it has sat there for longer than I like. It hasn't been a problem, meaning it hasn't shown up on the negative, but I'd rather avoid it if possible.

Tim