Children of Men by Alfonso Cuarón

The street battle where Theo (Clive Owen) has to take cover in a battered building caused concern for the studio, as it took fourteen days to prepare this one shot, with a delay of five hours every time it had to be re-shot. It was shot over the course of two days, but only one complete take was actually captured on film. In the middle of one take, some blood spattered on the camera lens.