With A Haunting In Venice Kenneth Branagh, or perhaps Haris Zambarloukos, the cinematographer, had a giggly mood when choosing cameras. They decided that since they will shoot on location in real Venice, they will need the new camera from Sony which is called Venice. And therefor they shot the movie digitally again. And this decision probably made it the first movie in the Branagh Poirot series to be in the 16:9 aspect ratio. Which is kind of weird for this franchise.
If they are not interested in books. Try film adaptations. Sherlock Holmes by Guy Richie starring Robert Downey Jr. is a good series of crime films to start with. Though they are a little cheesy. Sherlock feels more like a computer than a human being. Then perhaps you can jump to higher films of the same genre. Perhaps the Kenneth Branagh films about Hercule Poirot. Or perhaps the classic film "12 Angry Men". Or both.
It's interesting sometimes what different artists do with the same material when this material is not bound by copyright. Good filmmakers like Kenneth Branagh can make wonderful adaptation of things like plays by Shakespeare into insane epics. Bad filmmakers like Rhys Frake-Waterfield can make awful twists on beloved characters, like the horror film Winnie-the-Pooh: Blood and Honey.
I have a problem perhaps only with the casting in this movie. Everybody is too damn hot! It is a bit distracting. Also the lead actor Ansel Elgort looks a bit too much like my brother. I felt so much cringe through out the movie seeing my brother kissing Lily James ( Kenneth Branagh's Cinderella ). But other than that, the movie is very good, indeed.