BW x CT x (0,1,2,3)

Very Nice, Geoff, as I want to fly to JFK with TMAX400… and I have the same Pavoni (as the coffee shop) ;))

I think you would need far more exposure than three goes through an airport scanner (although I guess there might need some rogue scanners out there).
When I was doing my trips, the little 110 Pentax was just shoved in a pocket, it probably got 20 trips through the scanner, plus lots of high altitude radiation (not inconsiderable on a 9 hour flight to Seattle and back) without any terrible effects.
The radiation for extended periods at 36,000ft plus, is probably a bigger risk than the hand-baggage scanners.
There is obviously a risk to film (as there is to people), but I don't think people should avoid carrying film on planes, or worry tó much about it.
And I should stress: When I'm carrying stem cells, I'm absolutely adamant that they should not go through the scanner - but that is a matter of life and death, so you can't take chances, however small.

Good to know, thanks Geoff!

I can't remember the last time I flew with film. I can imagine taking a film camera on my next excursion to Hawaii.

Hi Geoff. I am almost ashamed to say this is my area and I have spent most of my working life training the people referred to. My trainees certainly get an informal introduction to dealing with film, though of course this is not covered anywhere in the legally biding syllabus documents. I was there and I suppose part of the process, when we first introduced CT for screening hold baggage and it was done with the very best of intentions. The 1980s were the pinnacle of a truly horrific problem we had to fight. We certainly didn't then envisage CT machines being able to go fast enough to cope with the screening processes demanded for cabin baggage (carry on), but that development was I suppose inevitable. CT technologies were quite well suited for the hold baggage task, but cabin baggage; well that is a different challenge and I have my own concerns. Pointless my being concerned, it is the general direction of travel. I should emphasise general. Not all airports have this technology and not all of the more advanced systems actually use CT. Having multiple x-ray sources and modelling from the data to build a 3D model is one approach and of the course the other is to just spin that beam around the tunnel quickly, firing all the way. CT inevitably exposes anything to considerably more x-ray than even multiple static sources and tube voltages tend to be higher as well.

If the UK or European airport you are departing from doesn't have Standard C3 (the C is for cabin) equipment, then your films, even faster ones, should be just fine through the equipment (you can ask the staff about this). Typically, your hold baggage is likely to go through a CT based system even where the airport doesn't have it for cabin baggage, so cabin baggage may still be the safest route. I have had much the same results that you saw with a recent test using Kodak Gold 200. One control, one screening by dual view x-ray 10 times and one twice by a beast of a CT machine. Results on all three were practically identical given minor variations on the 1950s Kodak cameras I then shot them, all on.

Hand searching of film? Well I would prefer to trust the machines really, although that's easy for me to say, I refuse to fly. Checking films by hand is from a security purist's perspective, a little less than satisfactory, unless the screener is pretty good with their behavioural analysis skills. I do informally explain to my students that if a person states that they have "very fast film' in their bag, they are likely to point towards a box of Ilford or Kodak marked as 3200 ISO and that if they have followed the advice of one 'expert' on Youtube, then that box is actually empty. I encourage them to just let the person know that we know that trick. Screeners generally get treated rather poorly by some of the travelling public, yet work with sophisticated technologies in a demanding and highly regulated environment. As with many other roles, they come from all walks of life and of course amongst them are some who love photography. Whilst some airports now have an especially sullen atmosphere, some of the regionals really aren't like that. I would urge anyone travelling to pass the time of day and discuss any needs. These folk have to deal with equipment associated with just about every trade and hobby under the sun. Some may have recent experience shooting film and might want to share the passenger's experiences with similar.

Thank you for a read that made me think and type too much. `

Thank you very much, Geoff, for the interesting test. It confirms what I had already read elsewhere – the effects are not so dramatic with films of low to medium sensitivity. I was surprised by the results in the article on Silvergrain Classics; I had never seen such dramatic effects before, but it doesn't seem realistic to me that films would have to go through the scanner more than twice during a trip. In another test, I also saw that the effects can be compensated for to a certain extent by slightly more generous exposure.

Fortunately, I have only had good experiences on my travels so far. Whether in Stuttgart, Hamburg, Frankfurt, Copenhagen, Helsinki, Bristol or Kerkira – upon polite request, my films have always been checked by hand. The security staff now seem to be used to photographers with film in their luggage again. The worst thing that has happened to me so far is that I had to open the packaging of my films. In Stuttgart, I was asked about my camera and had a short, pleasant conversation with the security officer.

Hey Geoff,
This is both interesting and reassuring. I took some film back and forth to Canada a couple of times early after I started shooting, and the only emulsion that had any noticeable impact was Delta 3200, which looked a little "washed out", but not uninteresting. Everything else that went through the scanners 1 or more times was 400 or lower and if there was any impact from the CT, I couldn't tell when it came back from the lab.
Thanks for doing this experiment!
Best,

s