One of the questions I get asked most often by graduate students doing ethnographic research is about how much data they need to collect. I think this is especially troublesome for those who are doing fieldwork somewhere far away, where limited time and funds mean that they will unlikely be able to make a return trip after they return from the field. But even those doing research closer to home want to know “How much is enough?” In answering this question I draw on my experience as a documentary filmmaker.
A “shooting ratio” is “the ratio between the total duration of its footage created for possible use in a project and that which appears in its final cut.” For a Hollywood film, where the scenes are planned in advance, this might be four to one. That is, shooting four hours of footage for every hour of the final film. Now that films have largely gone digital, producers no longer need to worry about the cost of expensive film stock, but it still costs a lot to have actors and crew out for a day and nobody wants to waste too much time shooting the same scene over and over again.
For documentary films, however, it is different. Continue reading