I'm not referring to the technical aspects of filming, I'm referring to the huge differences between them as a storytelling medium. A movie only has 1.5-3 hour

I'm not referring to the technical aspects of filming, I'm referring to the huge differences between them as a storytelling medium. A movie only has 1.5-3 hours of screen time available to tell the complete story (unless you do something like the recent "Dune" movies, or make a trilogy like LotR), but in addition to that, a lot of things that work for books don't work the same way for movies: pacing, etc.