While I consider myself something of a movie buff, I am out-buffed by one of my colleagues. This is a good thing—I enjoy the opportunity to hear about movies from someone who knows much more than I. We recently had a discussion about science-fiction classics and one sub-topic that came up was the matter of movies based on books or short stories.
Not surprisingly, the discussion turned to Blade Runner, which is supposed to be based on Do Androids Dream of Electric Sheep? By Phillip K. Dick. While I like the movie, some fans of the author hate the movie because it deviates from the book. This leads to two of the three questions.
The first question, which I think is the most important of the three is this: is the movie good? The second question, which I consider as having less importance, is this: how much does the movie deviate from the book/story? For some people, the second question is rather important and their answer to the first question can hinge on the answer to the second question. For these folks, the greater the degree of deviation from the book/story, the worse the movie. This presumably rests on the view that an important aesthetic purpose of a movie based on a book/story is to faithfully reproduce the book/story in movie format.
My own view is that deviation from the book/story is not actually relevant to the quality of the movie as a movie. That is, if the only factor that allegedly makes the movie bad is that it deviates from the book/story, then the movie is actually good. One way to argue for this is to point out the obvious: if someone saw the movie without knowing about the book, she would presumably regard it as a good movie. If she then found out it was based on a book/story, then nothing about the movie would have changed—as such, it should still be a good movie on the grounds that the relation to the book/story is external to the movie. To use an analogy, imagine that someone sees a painting and regards it as well done artistically. Then the person finds out it is a painting of a specific person and finds a photo of the person that shows the painting differs from the photo. To then claim that the painting is badly done would seem to be to make an unfounded claim.
It might be countered that the painting would be bad, because it failed to properly imitate the person in the photo. However, this would merely count against the accuracy of the imitation and not the artistic merit of the work. That it does not look exactly like the person would not entail that it is lacking as an artistic art. Likewise for the movie: the fact that it is not exactly like the book/story does not entail that it is thus badly done. Naturally, it is fair to claim that it does not imitate well, but this is a different matter than being a well done work.
That said, I am sympathetic to the view that a movie does need to imitate a book/movie to a certain degree if it is to legitimately claim that name. Take, for example, the movie Lawnmower Man. While not a great film, the only thing it has in common with the Stephen King story is the name. In fact, King apparently sued over this because the film had no meaningful connection to his story. However, whether the movie has a legitimate claim to the name of a book/story or not is a matter that is distinct from the quality of the movie. After all, a very bad movie might be faithful to a very bad book/story. But it would still be bad.
The third question I came up with was this: is the movie so bad that it desecrates the story/book? In some cases, authors sell the film rights to books/stories or the works become public domain (and thus available to anyone). In some cases, the films made from such works are both reasonably true to the originals and also reasonably good. The obvious examples here are the Lord of the Rings movies. However, there are cases in which the movie (or TV show) is so bad that the badness desecrates the original work by associating its awfulness with a good book/story.
One example of this is the desecration of the Wizard of Earthsea by the Sci-Fi Channel (or however they spell it these days). This was so badly done that Ursula K. Le Guin felt obligated to write a response to it. While the book is not one of my favorites, I did like it and was initially looking forward to seeing it as a series. However, it was the TV version of seeing a friend killed and re-animated as a shuffling horror of a zombie. Perhaps not quite that bad—but still pretty damn bad. Since I also like Edgar Rice Burroughs Mars books, I did not see the travesty that is Disney’s John Carter. To answer my questions, this movie was apparently very bad, deviated from the rather good book, and did desecrate it just a bit (I have found it harder to talk people into reading the books since they think of the badness of the movie).
From both a moral and aesthetic standpoint, I would contend that if a movie is to be made from a book or story, those involved have an obligation to make the movie at least as good as the original book/story. There is also an obligation to have at least some meaningful connection to the original work—after all, if there is no such connection then there is no legitimate grounds for having the film bear that name.