I’m teaching a course (two classes) this term on adapting non-fiction works to film, and some principles and results, so I’m interested in this thread big-time.
My position is that, given the gross number of characters and facts in almost any non-fiction account, the adaptor must select carefully which characters and facts go into the film, and ignore (or even distort) the others. In Nora Ephron’s phrase, the adaptor’s job is to “impose a narrative” onto the film–often, the film narrative is the same as the book narrative, but just on smaller scale (with several characters telescoped into one, for example) or with the narrative beginning much later or ending much earlier or both. Sometimes, however, the film narrative differs, sometime radically, from that of the book narrative, as when a filmmaker likes something about the book but has a vastly different interpretation of what those events mean, or what the audience will tolerate.
I’m using ADAPTATION (The Orchid Thief), A BEAUTIFUL MIND (Nasar’s book of that title), HURRICANE (Carter’s THE SIXTEENTH ROUND) in the course for sure, and possibly JFK, ERIN BROCKOVICH, SILKWOOD, OUT OF AFRICA, QUIZ SHOW or other films as time and interest permit. It should be interesting, I think, and I expect to learn much as I get into it.
I think it’s impossible for a film to be true to the book, most of the time, if by ‘true’ we mean a literal rendition. It’s possible that some of these works would make some of the same points as the book (or newspaper accounts, as in the case of JFK and some of the others) but not necessarily. Radical divergences, such as in my first two films, try to tell a higher truth by distorting the unwieldy story-line of the original, though I’m not sure that by changing certain central facts they’re distorting the intent and the meaning of the book. Rather, I think they’re making the themes of the book come through more strongly by avoiding getting bogged down in details that are acceptable in a non-visual medium that can be enjoyed in interrupted segments.