When I visited Russia .../...there were more X-ray machines than I had ever encountered before .../... security at Moscow airport either didn’t understand what I was asking or simply wouldn’t make exceptions even for very fast film.
I didn’t develop or scan any of the film myself, but I didn’t see anything I would attribute to X-ray damage. I’m still paranoid about CT damage though.
yes in Russia x-ray starts at the border customs. Coach stations, railways stations, airports have x-ray tunnels at the entrances and big airports have also additional x-ray tunnels in transit corridors. As you mention, museums and some other public places. So every time you travel there is an x-ray pass, but these don't indeed damage film up to iso 400 for sure. I am frequent traveler and never experienced any damage, with films that went through 15x -rays along the way.
Still I prefer to lower the amount of passes, by asking for side inspection at airports.
Last time was five days ago on a Murmansk-SPb flight. As soon I pronounced photographic film, the agent very kindly told me "oh yes give it for side inspection", yet they don't use CT machines. The side inspection was some kind of hand held device put over the rolls.
after once at Oslo airport I had to unpack all rolls from their boxes, and ended with a mess of unknown Fomapan isos because the white paper foil has no marking, since I always throw the boxes, mark the foil, pack all rolls thigh in a clear plastic, so I hand the small pack to security. This the exposed one from last week in Murmansk, SPb, Pskov, still had no time to develop:
sheet film, I have a sheet outside the box, so to show that it is negative film.
In Russia they may not understand what you mean unless you say it in russian: plionka is photographic film, but then no issue.
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Airports i have been at in recent years do all graciously a side inspection: Oslo, Genève, Lyon, Bruxelles, Berlin, Hamburg, Tallinn, Riga, Gdansk, Warszawa, Krakow, Vilnius, Helsinki, Murmansk, Sankt Peterburg, Pskov, Vnukovo, Sheremetyevo, Domodedovo, Magadan, Yakutsk (well these two are in Asia). It is a non issue.