New (as of 2019) airport CT scanners

wiltw · Mar 24, 2025

Of interest in this very thread, a post in 2019 in which radiation dose of hand luggage was MEASURED using dosimeters. This measurement without implication on visibility (or lack thereof) of radiation damage to film. I link to this for the benefit of those recently joining this lengthly thread, who have not taken the time to read it in its entirety, since it does contain very relevant factual information

New (as of 2019) airport CT scanners

thank you guys for your thoughts but how about hesitations from security personnel for films manual checking ?

www.photrio.com

Additionally, one person published on YouTube a report in which he deliberately subjected film to 16 passess thru X-Ray without much more that some increase in grain evident. And in that same thread, a 18 year veteran professional pilot relates his freedom from any evidence of damage to his film during his career

wiltw · Mar 24, 2025

koraks said:
The report does, but your post offering the quote of the person interpreting the report does contain a somewhat haphazard assumption that's presented as if it's a firm conclusion:

The report lists (page 24 of the pdf) measurements for baggage passed through hold luggage CT ('CTX') vs. regular hold luggage x-ray scanners ('L3 EDS'), with a passing remark about carry-on regular x-ray machines which your conclusion seems to rely on. CT scanners for carry-on luggage were not included in the report because none were in use at the time of the study (late 2003/early 2004). The conclusion in blue quoted above relies on the assumption that the x-ray dosage and profile of today's carry-on CT scanners will be the same or similar to that of checked luggage CT machines in use 20 years ago. In reality, we don't know this. Your conclusion may or may not be correct. We just don't know, and we sure can't tell much about machines installed in the 2020s based on a 2004 report. The person you quoted picked his words more carefully and said "The newer carry-on screening systems are expected to deliver similar doses." (emphasis mine; note the somewhat cautious formulation signaling an assumption on his part).

Btw, the defects I encountered are easy enough to miss if you don't process your own film and don't examine it closely. I first noticed it on the empty leader part of the film that is typically not returned to the customer after processing, unless the customer requests uncut film. This is a typical black swan scenario; one might assume on the basis of observations of only white swans that all swans are white. Observations of white swans, however, do not demonstrate the absence of black ones.

I drew no conclusion about the amount of dose from current carry-on scanners at all. I provided the link primarily because of the validation of the low X-ray dose in hand luggage examination devices.

In fact, I *speculate* that they may in fact have a preliminary very-low dose that they selectively can increase for better imaging and analysis of the density/composition of contents for explosives detection. That is, initial use of X-ray detection, with initialization of CT only when automated detection warrants, to speed up examination of handluggage. That would account for why so many reports of 'no damage' from carryon CT, while other reports have exhibited patterned artifact. It is known that there are multiple technologies of detection involved in luggage examination systems. The volume of caryon CT was about 10 bags per minute.

koraks · Mar 24, 2025

Whatever. I deleted the post you quoted for the reason I mentioned.

wiltw · Mar 24, 2025

koraks said:
You're overlooking the fact that film rolls aren't necessarily fed neatly vertical or horizontal through the machine.

Empirical evidence of CT damage shows overall fog with no clear geometry. Empirical evidence of regular X-ray damage looks exactly like what I linked to in my experience.

Single or dual- view systems usually scan baggage as it moves on a conveyor using a fan beam or a scanning pencil beam of X-rays in a fixed geometry. Multi-view CT sensors, on the other hand, usually scan stationary or moving baggage in a fixed geometry of scan angles and process
data corresponding to the absorption of X-rays to reconstruct selected slices of the baggage.

Use of a fan beam irradiates uniformly an area under the beam, leaving the entire field irradiated. A scanning pencil beam of X-rays could leave the sinusoidal pattern. But unless employ multiple sources or a mobile source, the result is only a 2-D image X-ray, yet the carry-on CT is 3-D in view.

wiltw · Mar 24, 2025

koraks said:
Whatever. I deleted the post you quoted for the reason I mentioned.

Censorship of objectively obtained information, with no political commentary?!

MattKing · Mar 24, 2025

wiltw said:
Censorship of objectively obtained information, with no political commentary?!

He deleted his own post.

koraks · Mar 24, 2025

MattKing said:
He deleted his own post.

Indeed ; I realized I was only adding to an already meaningless word salad.

MattKing · Mar 24, 2025

Gentlemen.
Can we agree that you don't agree about the reliability of the warnings or lack of warnings re: lower than ISO 1600 speed films, or the methods used to challenge or support those warnings?

wiltw · Mar 24, 2025

MattKing said:
Gentlemen.
Can we agree that you don't agree about the reliability of the warnings or lack of warnings re: lower than ISO 1600 speed films, or the methods used to challenge or support those warnings?

I see no 'disagreement' other than the question if X-ray security scanner was truly the cause of the artifacts seen in his film. Going back decades, there were some reports of damage to film supposedly from passing thru security X-ray, and to magnetic media transport on their belts. So the fact that damage occurred is uncontestable...the question is the true source of the damage. That is why I cited folks saying 16 deliberate passes or an 18 year tenure as a pilot, both withour harm to film, as the counterpoint. And also the variety of results seen with CT security machines!
We have, after all, decades of refusal to hand inspect while pointing to the signage disavowing film harm. and in spite of that there seems to be few complaints about damaged film!

wiltw · Mar 24, 2025

wiltw said:
Censorship of objectively obtained information, with no political commentary?!

...said in jest, posted without the accompanying smilie!

ntenny · Apr 11, 2025

I’m in the final legs of an itinerary to Wuhan, China: PDX-SEA-PVG-WUH and back. I’m writing this from the lounge in Shanghai (PVG), so I have one more security check to go when I enter the US in Seattle, but I expect that to be the same as previous trips and uninteresting from the film pov (plain X-ray, I never ask for hand check at it).

PDX outbound: all CT, no problem with hand check, as always. They knew what my film was (four rolls of 135 in canisters, in a plastic bag with folded HP5+ and D3200 boxes for identification).

SEA: didn’t have to clear security, but all I’ve ever encountered there is old X-ray machines.

PVG: X-ray again when I entered China and transferred to the domestic section of the terminal. I didn’t ask for a hand check. They are very picky about making sure that all battery packs/power banks come out and are hand-checked (this seems to be general to China) but the camera and film didn’t excite any comment.

WUH: no security check on arrival from a domestic flight.

WUH return: basically the same as PVG, plain X-ray with their apparent main concern being power banks. The staff in my line didn’t seem very communicative, and I wouldn’t have a lot of confidence in asking for special treatment, especially without speaking Chinese. (Phone translator apps are a godsend in China, but not always reliable…)

PVG return: you go through passport control to leave China, and there is a security check afterwards. Similar to the outbound, it was a plain X-ray; no reaction to film or camera.

Wuhan turns out to be an OK photographic city, by the way. I was in the Optics Valley area, where there’s a very large lake with green spaces around it, so I was able to do some light populated landscapes. The streets were unrewarding for me, but I’m not a very good street photographer and someone with a better eye might have found some stuff. The Yellow Crane Tower was worth a visit and offered some cityscape views, and maybe more for someone with an eye for architectural details.

-NT

Dr. no · Apr 14, 2025

Trip report:
Albuquerque: the new precheck line has brand-new CT scanners, and no problem with a hand check (he swabbed each of 20 rolls of 120 in two baggies).
Schiphol (Amsterdam): all new CT scanners on departure, one person didn't recognize film when I asked for a hand check but her partner said "I'll take care of it".
San Fransisco precheck: old machines, didn't bother with hand check.
No fogging/artifacts (except for a roll of Fuji 800 35mm of completely unknown vintage that came along by mistake, it was in the bag of Superia 200)

loccdor · Apr 14, 2025

CT scanners in Buffalo, New York and Charlotte, North Carolina. I was able to send film through the mail so it didn't matter this time for me.

I kind of wanted to put some 50 speed through the scanner to see if the fog level was no big deal for me, but I didn't.

Dr. no · Apr 15, 2025

I have a bag of FP4 (no plus) bulk rolls...I might just keep a roll in each bag and pull off a foot to develop after each trip. Just for kicks. I know it has some base fog, but I would look for CT artifacts.

wiltw · Apr 15, 2025

Dr. no said:
I have a bag of FP4 (no plus) bulk rolls...I might just keep a roll in each bag and pull off a foot to develop after each trip. Just for kicks. I know it has some base fog, but I would look for CT artifacts.

I have two rolls of exposed and unprocessed NPH 400 rollfilm which I will be deliberately placing inside my carryon luggage, with the hopes that I identify that the carry-on is indeed going thru a security CT scanner at the gate, and I will deliberately NOT ask for hand inspection in choosing not to bypass the CT imaging. We are leaving SFO, travel thru Toronto, to Lisbon outbound this later week. Then returning Lisbon thru Montreal to SFO two weeks later. I will have roll 1 go thru CT only outbound, with roll 2 going thru CT only upon return if I encounter CT in both directions. so that each roll independently will represent a different CT scan in a different location.

Dr. no · Apr 15, 2025

And just because we love complexity...
The film that was loaded in holders went through the scanners. No discernible artifact from ABQ on Arista EDU Ultra 400, and the return trip is not developed yet.

wiltw · Apr 15, 2025

Dr. no said:
And just because we love complexity...
The film that was loaded in holders went through the scanners. No discernible artifact from ABQ on Arista EDU Ultra 400, and the return trip is not developed yet.

Was it positively identified to be CT scanner that was used for security inspection?

Agulliver · Apr 16, 2025

I'm currently in Tokyo having travelled from London Heathrow to Kansai International via Helsinki then a week later taking the shinkansen (bullet train) from Kyoto to Tokyo

LHR terminal 3 seems to still have old x-ray scanners. I asked the security bod and he said it's safe up to 800 ISO. I'm carrying nothing faster than 400 so was ok with it being x rayed.

No security check transiting through HEL (lovely airport). No security check for the train to Tokyo

There are older x-ray scanners in some lines for the Expo 2025 in Osaka but my group included a wheelchair user and we all got hand checked. Security man was older and thrilled to see film cameras.

I'll report on Tokyo next week after I return home.

BTW the expo is not worth it and in my opinion transport and queuing are so disorganised that someone is going to be killed in a crush

Dr. no · Apr 17, 2025

wiltw said:
Was it positively identified to be CT scanner that was used for security inspection?

Yes. But I don't know if it's one that can be switched to "high-power" for a better look when there are questions...

Fatih Ayoglu · Apr 19, 2025

Agulliver said:
I'm currently in Tokyo having travelled from London Heathrow to Kansai International via Helsinki then a week later taking the shinkansen (bullet train) from Kyoto to Tokyo

LHR terminal 3 seems to still have old x-ray scanners. I asked the security bod and he said it's safe up to 800 ISO. I'm carrying nothing faster than 400 so was ok with it being x rayed.

No security check transiting through HEL (lovely airport). No security check for the train to Tokyo

There are older x-ray scanners in some lines for the Expo 2025 in Osaka but my group included a wheelchair user and we all got hand checked. Security man was older and thrilled to see film cameras.

I'll report on Tokyo next week after I return home.

BTW the expo is not worth it and in my opinion transport and queuing are so disorganised that someone is going to be killed in a crush

Just used T3 LHR on Thursday 17th April, the staff has confirmed they have all CT machines, also new ones are getting installed. I have asked about the film, he was very clear "if you have any film, approach to the staff, handover for manual inspection, we don't let them go through the machine." Just FYI

Agulliver · Apr 20, 2025

Fatih Ayoglu said:
Just used T3 LHR on Thursday 17th April, the staff has confirmed they have all CT machines, also new ones are getting installed. I have asked about the film, he was very clear "if you have any film, approach to the staff, handover for manual inspection, we don't let them go through the machine." Just FYI

Definitely older Smiths X-ray scanners two weeks ago in T3. I specifically asked and the security man I spoke to was familiar with the difference between the older X-ray and CT scanners, these were the older ones and safe up to 800 ISO. The Smiths machines were the square box type, pretty old and battered. Definitely in T3 on 5 April. Perhaps they are in the process of replacing them but the 4 I saw were the old ones. The good news here is that the staff seem aware. I'll be developing some B&W film either today or tomorrow....I am currently on 6 hours sleep in the last 48 hours though so we shall see. Colour film is going to my local lab on Tuesday.

Tokyo Narita airport T2 the scanners appeared to be regular X ray scanners, I asked if they were safe for film and was told "OK for film" but they offered to hand inspect my film anyway, so I had my film hand inspected there. The old rules of 100ml liquid separated zipped bag and remove electronics from your bags were in effect too.

This time I was required to go through security again at Helsinki. Looked like older X-ray machines and again the old rules were in place....but again the staff were happy to hand inspect my film when I asked if the scanner was safe for it. They did insist on examining each and every box. I ended up with about 10 rolls of 35mm, two 120, two std 8mm and two packs of Polaroid Go so it took time. However, they were very friendly about it and instantly recognised the film boxes (mostly Kodak). Having the older x-ray scanners did surprise me as their website states they have CT scanners now. Very friendly staff all through this airport.

As expected, no x-ray or other scanning/searches for the Shinkansen (bullet train). However there are x-ray scanners for Expo 2025 in Osaka. I also thoroughly discourage anyone from going anywhere near Expo 2025. I'll be very surprised if nobody is killed in a crush situation there. NB I was part of a group where one person was in a wheelchair, so we got in quicker and our bags were hand inspected as the wheelchair needed to be hand inspected. The older security guy who looked at my bag was absolutely thrilled to see film cameras. And I was certainly not the only one there shooting on film.

Agulliver · Apr 21, 2025

Quick update, I developed a roll of PanF+ and a roll of Fomapan 400 from the trip today. No problems as far as I can see from the negatives. Not that I expected any.

Craig · Apr 22, 2025

I went through Toronto YYZ terminal 3 and had a roll of XP2 in a Nikon F6. No signs of X ray damage, film looks uniform in the unexposed leader.

Agulliver · Apr 25, 2025

Final update, all colour, B&W and cine film developed successfully after my trip to Japan. As all airports conducted hand inspection I was not surprised to find everything fine with the developed film.

BTW the way to get noticed in good ways in Kyoto and Tokyo is to shoot 8mm film. The monks at one of the Buddhist temples were really interested, one asked if it was video tape and when I said 8mm film his face lit up "oooh, very old camera". The young folk who populate Shinjuku by night also thought it was very cool that I was shooting cine film. That and my fashionable (for the area) dyed blue hair got me "in" with the youngsters. came in handy when we needed to create space for a wheelchair user to get through a group of people. My new friends made the crowd part like the red sea!

I saw quite a lot of people with older film cameras at various tourist sites, as well as a few Instax users. Found film for sale in several larger camera/electronics shops. One seemed to have just about every film in every format and also processed film. Had I wished, I'd have had no trouble buying film or getting it processed in Tokyo...35mm, 120, sheet, super 8....all available easily and at good prices.

Next flight is probably Luton to Heraklion (Crete) in October.

Sirius Glass · Apr 25, 2025

Agulliver said:
Final update, all colour, B&W and cine film developed successfully after my trip to Japan. As all airports conducted hand inspection I was not surprised to find everything fine with the developed film.

BTW the way to get noticed in good ways in Kyoto and Tokyo is to shoot 8mm film. The monks at one of the Buddhist temples were really interested, one asked if it was video tape and when I said 8mm film his face lit up "oooh, very old camera". The young folk who populate Shinjuku by night also thought it was very cool that I was shooting cine film. That and my fashionable (for the area) dyed blue hair got me "in" with the youngsters. came in handy when we needed to create space for a wheelchair user to get through a group of people. My new friends made the crowd part like the red sea!

I saw quite a lot of people with older film cameras at various tourist sites, as well as a few Instax users. Found film for sale in several larger camera/electronics shops. One seemed to have just about every film in every format and also processed film. Had I wished, I'd have had no trouble buying film or getting it processed in Tokyo...35mm, 120, sheet, super 8....all available easily and at good prices.

Next flight is probably Luton to Heraklion (Crete) in October.

Heraklion, Crete is definitely worth going to see. Enjoy your visit.

New (as of 2019) airport CT scanners

wiltw