It is the downfall of many writers to believe that books are cinematic. They aren’t. If you write a book, you don’t get special effects and pyrotechnics. You don’t get vast visual images to relay a lot of information in a very short period of time. The strengths of visual art are different from those of written art.
That is why so much information tends to get cut when converting a book into a movie. You only get words and space. Movies get far less words and space, but gain visuals. One page of script is one minute of screen time, generally. Think about that when you are writing the hundreds of pages.
Even if this were not enough, the pacing of a movie does not work for a book or vice versa. Pick a book you liked that had a movie adaptation. Read a scene, then watch it in the movie. Sometimes it is done almost the same, other times it has been drastically altered. Why? Books aren’t Cinematic. Books are books.
I would think that would go without saying, yet I have read a fair number of unpublished author’s works that seemed to try conveying some lengthy fight or explosion scene. Something that can be done with just words, but which they fail to convey because they are describing it more like a movie than a book. It feels slow motion when describing every detail. That is the last thing you want in an action scene.
This isn’t just my observation. I have read a number of editors and agents who have had the same complaint. Too many writers seem to be describing something they saw in a movie rather than pacing out a scene for a book. Don’t get caught in this trap. Accept that books are books and movies are movies. The two can go hand in hand, but they are never the same even if they both find a way to effectively convey the subject matter.