There is an old piece of wisdom among film photographers: anything ISO 800 or slower can safely go through the carry-on scanner. It dates from a time when every airport checkpoint used conventional X-ray machines. But as CT scanners have arrived at one airport after another, film manufacturers have started changing what they tell customers. Before you think about film speed, there are now two things to check. What kind of machine is at the checkpoint you will walk through, and is the film in your bag still undeveloped?
CT is X-ray too
In the words of the U.S. Transportation Security Administration (TSA), a carry-on CT scanner uses X-rays to build a three-dimensional image of what is inside a bag. Screeners turn that image this way and that on the screen as they look it over. Older scanners showed only a flat image. People tend to talk about X-ray scanners and CT as if they were different machines, but both use X-rays. For convenience, this article calls the older flat-image scanners "conventional X-ray" and the newer 3D scanners "CT."
What the manufacturers say
HARMAN, the maker of ILFORD film, says in its technical FAQ that it considers the new carry-on CT scanners unlikely to be safe for its ILFORD and KENTMERE films, whatever their speed. It cites initial test results and adds that it will revise the guidance after further testing. Conventional X-ray machines get separate treatment, and even there HARMAN advises asking for a hand inspection for DELTA 3200. It also notes that whether you get a hand inspection varies by airport and by country.
Kodak, in shipping guidance for its motion picture film customers (updated June 2023), warns that the new carry-on CT scanners will fog undeveloped film. In Kodak's view it makes no difference whether the film is fresh or already shot. If it has not been developed, the risk is the same. Both companies say to keep undeveloped film out of checked baggage, because checked bags are screened more intensely than carry-ons.
The two sets of guidance cover different ground, though. Kodak's document was written for motion picture film, and HARMAN's assessment applies only to its own products. Neither offers figures on how much damage occurs or after how many passes it becomes visible.
Kodak's film storage guidance also explains that X-ray effects add up. Each pass through security, at departure, on a connection and on the way home, can add a little more fog and grain. That passage, however, was written with older low-dose carry-on scanners in mind, so it is hard to apply directly to the new CT machines.
This figure accompanies Kodak's shipping guidance. It names the equipment and nothing more, with no model, dose, number of passes or test date. Presenting it as what a single trip through a modern carry-on CT scanner does would be reading too much into it.
Developed or not?
Film you have not shot yet needs to stay away from CT and strong X-rays. It makes no difference whether it is still sealed in the box, sitting in its canister or loaded in a camera.
The same goes for a roll you have shot to the last frame and rewound. Until it is developed, it still reacts to light and X-rays.
Developed negatives and slides are another matter. Kodak explains that processed film no longer reacts to light, and suggests having film developed at your destination before you fly as an alternative. Heat, humidity and scratches, of course, are a separate problem.
Unprocessed photo paper and instant film are different materials from film, so check the guidance for each product separately.
A hand inspection is only a request
The TSA advises carrying undeveloped film, and cameras with film in them, in your carry-on, or asking for a hand inspection at the checkpoint. The item table on the same page lists film as allowed in both carry-on and checked bags. But being allowed to bring film along is one thing, and the film coming through unharmed is another. The page also states that the officer at the checkpoint makes the final call on what is allowed.
Kodak, too, notes that local staff can turn down a request for a hand inspection. And a U.S. agency's recommendation does not carry over to airports in other countries. London Heathrow says security equipment and rules differ from airport to airport, and tells travelers departing from elsewhere to check that airport's guidance.
How to get a hand inspection at a Korean airport
So what should you do at Incheon or Gimpo? At Korean airports, the procedure depends on the film's speed.
Film rated ISO 400 or higher will be hand inspected at the security checkpoint if you ask. Slower film can be hand inspected only with an official special security screening permit letter.
Here is how to get the letter. First, download the Application for Permission for Special Security Screening of Items (특별 보안검색 물품 허가 신청서, Attached Form No. 1) from the website of the Ministry of Land, Infrastructure and Transport (MOLIT) and fill it in. The processing period printed on the form is three days. On the application, list only film below ISO 400, down to the name, format, speed and quantity, and leave out anything rated ISO 400 or above. Submit it through Munseo24, the government's e-document service, to the security division of the Regional Office of Aviation that covers your departure airport. Incheon and Gimpo fall under the Seoul Regional Office of Aviation. Attach supporting material showing that film is affected by X-rays, such as Kodak's advisories, as PDFs, and when the reply letter arrives, print it out. At the airport, hand the screener your film, sorted by type into separate zip bags, together with the letter.
The legal basis is Article 13(3) (special security screening methods) of the Enforcement Decree of the Aviation Security Act. Items that screening equipment could damage or alter can, with permission from the Minister of Land, Infrastructure and Transport, be screened by opening them or checking supporting documents instead (subparagraph 5). Photographic film goes through this permission; medical and scientific film is listed separately in subparagraph 4-2 of the same paragraph. The same process works for a domestic flight, such as Gimpo to Jeju. Screening equipment varies from airport to airport. As of December 2025, most checkpoints at Incheon's Terminals 1 and 2 had switched to CT, while Gimpo and Jeju were still using older X-ray machines.
Even with a letter in hand, the final decision rests with the staff on site. And the fact that ISO 400 and faster film can be hand inspected just by asking does not mean it is safe to put through CT. As we saw above, Kodak and HARMAN set no ISO threshold for CT.
Before you go
These are our suggestions. None of them will get you a hand inspection at every airport.
- Look up the official guidance in advance for every airport on your trip, at departure, transfer and return. Even an answer you get ahead of time is no guarantee it will hold at the checkpoint.
- If you are flying from a Korean airport with film below ISO 400, apply for a special security screening permit letter in advance. Leave plenty of time for the processing period printed on the form.
- Pack film, and cameras with film in them, where you can get them out quickly. Kodak recommends a clear, resealable bag.
- Before anything goes on the belt, tell the screener it is undeveloped film and ask whether a hand inspection is possible. If the answer is no, follow the staff's instructions.
- Do not put undeveloped film in checked baggage.
- If a hand inspection is hard to count on for your trip, you can also buy film where you are going and have it developed there before you fly home. This is an alternative Kodak suggests.
Some readers may be thinking of a lead-lined pouch. Lomography's Korean-language guide carries a link to buy one alongside a description of how it protects film. But how much it actually blocks in front of a CT scanner is not known, so we do not recommend it as a substitute for a hand inspection.
Film speed is still a number worth weighing. But there are questions to ask before it. What machine is this checkpoint using, and is this roll still undeveloped?
