Fiction into Film: a Few ideas
I'll try to do this without burdening you with technical language.
As you know, the novel is made up of words, and words can conjure up anything -- images, ideas, feelings, qualities, things -- at any time in almost any sequence.
The film is made up of images, with some words, sound and music: it is of course very visual, very compelling, but at all times the images are filling the whole screen, and it doesn't have the capacity of language to evoke so much so quickly.
Film uses many codes and techniques to get its meaning across -- camera angles, panning, the speed of cuts, lighting and color, the association of images and so forth. These are not in the novel, as such, with the exception of the association of images.
In terms of the use of images, the novel relies heavily on metaphor. Unless it is spoken, it is very dificult to 'do' metaphor in film. Film relies on metonomy, or the use of a part for the whole (with, of course, the associated cultural meanings of the images)
The novel can go into the interior of individuals easily, it can have a narrator to guide the reader, and can cut rapidly back in forth in time and space. Film cannot enter the interior easily :it needs sets of visual, audial (e.g. music) and action codes, its only narrators are the possibility of voice over (warning: use sparingly) and the technique of either focusing closely on one character of seeing everything as if from that person's vision, and as it is tied to sight it can't jump so quickly in time and place.
So, what can be taken from the novel to the film?
- The action, or 'story line" can be, although not always the plot, or ways the action is arranged to make meaning
- the characters
- elements of setting and images associated with it
- the large, general cultural meanings.
The novel also is generally longer than the film can be.
All this means that you can't just change a novel into a film. Nor would you want to. You would probably want to keep the central actions, main characters, and large general idea, although the later may be open to interpretation, and it is legitimate for a film to change some of the emphases and even ideas a novel. But you have to truncate, often cutting and re-arranging both action and supporting characters at least, and you generally have to change the whole structure of the story around, on the one hand to deal with what the film can't do, on the other hand to make it as entertaining as possible using all of film's fine dramatic, visual and audial resources. A film is always a re-interpretation, not a copy, of necessity. Keep in mind, too, that a film is much more expensive to make than a book, and so it generally has to treat the subject in a way that is going to please many people.