It actually depends on the film maker's vision as to how he sees and conceptualises things. Characters or settings which have a particular impressions on our minds, and look completely out of sorts in the movie, are a result of bad vision on the director's part. As far as capturing the subject matter is concerned, cinema makers do have to take the liberty to concise a 400-800 page book to a 3 hour celluloid dream. And as far as potrayal is concerned... it depends on the actor's sincerity and depth behind playing a fictional character, which might have been popular earlier, and he/she has to live upto huge expectations.
