Why cant I perform the same inspection with a regular camera with infrared film, or even with night vision goggles?
A regular film camera captures only reflected energy, which is what is visible to the human eye. For infrared film, a temperature of approximately 527F degrees (275C degrees) is required to produce an accurate image of emitted radiation. Any image produced on the infrared film from lower temperatures will be due to reflected energy rather than emitted energy. Night vision goggles actually give off infrared energy that is usually not visible to the unaided human eye. The energy is then reflected off the objects in the scene and is then visible to the night vision equipment.
