Never put film in checked baggage. They use a new type of baggage scanner that will penetrate the commercially available film carryon pouches. The new scanner is like a CT scan, uses a very narrow beam of xrays to produce a cross-sectional view of your bag.(posted 8664 days ago)Modern scanners for carry on luggage are said not to affect film below about 400 speed. (This is for equipment used in the USA, they may use different equipment, more penetrating xrays, higher dose, etc. overseas.)
I always tuck my film into one of the pouches for xray protection anyway.