You can consider several different opinions to be true when comparing the text of a novel to its movie version because

The text of a novel is more explanatory with details and the setting. In the movie version of novels, the movie is just flowing which makes it almost seem to be shorter. As to the text of a novel it's said/explained when a noise is made or when somebody walks in or by. In my opinion, although it would take more dedicated time to read the text of a novel first and the movie second it would give the reader's and viewer's a better understanding of what is being watched in the movie version.