The Book of the Film of the Book ...
I've got a new way of writing my time away.
First I write the book (that's countless drafts and a number of years as a rule). And this new thing is to revisit the whole thing by turning it into a screenplay.
New software helps the game along. There are a number of CD packages out there, though everyone I know in the business swears by Final Draft (not available in the UK for some reason ... get a friend to mail you one). One of many features is that it lets you feed a whole novel into its format. It then makes a valiant stab at turning deft prose into a screenplay ... and obviously fails miserably! What it does is save you loads of typing. Material is there to paste in to the proper places ... or more likely to delete.
I know the standard rule is to treat the screenplay as a wholly new beast, allow fresh invention to the come to the fore. So the novel CHOCOLAT is contemporary while the film is set in the 50s, for example. This is a great way for the screenwriter to take on material as his / her own ... but not, I reckon, so necessary for the novelist who has already cut and reshaped and drafted the material through endless imaginative revisions. One more may do no harm, but isn't definitely necessary.
I write my books in a visual way in any case, so reckon they transfer well to film. One immediate challenge is working out what to throw away - a great deal. It doesn't mean it's not necessary in the book (though it begs the question), just that things need trimming to the bone to fit into 120 minutes.
The dialogue's interestin. In a book, I'll often use dialogue to explain the action, to give details of the location. When you see the action and location onscreen, that dialogue becomes unnecessary. Also discursive dialogue in the book needs dropping in favour of something snappy. I've been delighted with some of the one-liners that came up for the film version - then puzzled on going back to the novel to find I didn't want to include them there. Maybe because a film is so big it takes big oneliners to stand on their own, but the same lines look brazen in the context of the written page, which is indeed a far subtler medium.
The film relied more on the relationship between characters. That was probably the most useful thing to learn and bring back, increasing and sharpening those human scenes.
And now, of course, I need to run the screenplay through several more drafts. Who know where it will all end up.