Novelists are not equipped to make a movie in my opinion. They make their own movie when they write: they're casting they're dressing the scene they're working out where the energy of the scene is coming from and they're also relying tremendously on the creative imagination of the reader.
If I pick up a book with spaceships on the cover I want spaceships. If I see one with dragons I want there to be dragons inside the book. Proper labeling. Ethical labeling. I don't want to open up my cornflakes and find that they're full of pebbles... You need to respect the reader enough not to call it something it isn't.