This is something that’s being discussed all over the web at the moment – following a presentation by Rob Hummel at Cine Gear Expo 2011. In his talk, he states that when cameras are transported by air, at over 20,000 feet, gamma rays (harmless to us) can damage the sensor, causing dead pixels to appear. Most of the information I’m referring to happens about 8 minutes in.
The whole thing though is a great explanation of how your camera sensor works, and how it compares to the way film is manufactured, and remains sensitive to the different colours of light. Watch, learn, and make your own decision….