For "Interstellar," director Christopher Nolan created worm holes, planets made of ice and water, robots that look like Kit Kat bars and even a fifth-dimensional tesseract. So asking cinematographer Hoyte van Hoytema to pick the biggest challenge he had in bringing Nolan's film to visual life amounts to a fool's errand. "What I should tell you about it is that I've never been involved in a film where every single day we did something new," van Hoytema told HuffPost Entertainment in a recent interview when asked about the toughest shot in the film.