To watch atmospheric and astronomical phenomena that normally unfold too slowly for convenient observation—from moving clouds and stars to variable stars and novae—we often use time-lapse photography, compressing a long event into seconds or minutes. For phenomena that occur too quickly for human eyes to follow in detail, such as lightning, we instead need high-speed imaging that lets us watch the event in slow motion. [source] [source]
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One of Harold Edgerton's best-known photographs shows a bullet passing through an apple. Taken in 1964 with an exposure of roughly one millionth of a second, it became an iconic example of high-speed photography. Edgerton, an MIT electrical-engineering professor, pioneered techniques using repeated flashes of light to freeze extremely rapid events. [source]
Modern slow-motion cameras record large numbers of frames per second. Consumer products were already becoming capable of around 240 frames per second when this article was written. But to study something as fast as a bullet, ordinary consumer cameras are insufficient. A camera capable of at least 10,000 frames per second, the source explains, can make a projectile travelling near 300 metres per second appear to move at only a few centimetres per second when played back slowly. [source]