The Pit and the Pendulum: Movie vs. Book

The Pit and the Pendulum is a book written by Edgar Allen Poe in 1842. Years later, in 1961, a movie was made. Directed by Roger Corman, the film is a lot different than the movie, though it does have a few similarities. One of the few similarities is the pendulum sequence. When Francis is strapped down to the “bed,” the pendulum comes inches closer and closer, slowly, as in the book. Right as it’s about to kill him, he’s saved. Another similarity, though minor, is the involvement of a pit.
A major difference is the involvement of a plot. In the book, there’s almost no plot at all, except that a character is a military man in France. In the movie, the plot is long, explained well, and a little more interesting than the book. The pit and pendulum themselves have very little involvement in the movie, while in the book, they’re almost always involved and the pit is introduced almost right away. Also, in the movie, there are way more characters. I think Roger Corman did a pretty mediocre job making a movie out of the book.
I understand that the movie wasn’t really meant to be based on the book entirely, but they could have involved the pit and the pendulum a little more throughout the movie. Although the plot was good and had plenty of shocks, I did like the plot of the book a little more. If I wrote the script, I would have added a lot more to the plot of the book and kept it. It seems like Corman just made the movie with the title, and only had the pit and the pendulum stay. In short, Corman could have done better.