Shadows and darkness were definitely going to be key components in the film’s visual plan, but strong daylight sources were also important in order to create emotional contrast in certain scenes.
"We didn’t want the audience to feel as if they had been sucked into two hours of darkness. Psychologically, people don’t like to be in the dark, and 120 minutes of darkness can become depressing to watch. Also, the impact of any extreme lighting effect will wear off after a certain point. For example, if an entire film is shot with green-tinted lighting, the effect may seem imposing at first, but the eye will adapt, and after a while the audience won’t even see the green anymore. The same thing happens with light and dark. If there is no alternation between light and dark, there is no relief, so the dramatic tension of being in the dark is gone."
- Karl Walter Lindenlaub, ASC, BVK