Filming began on Monday, December 11, 1989, and lasted for seven days. The episode was directed by David Carson, who had only filmed one other "Next Generation" episode before "Yesterday's Enterprise". Carson felt that his relative lack of experience helped because he had no preconceptions about how episodes should be directed. Since much of the episode took place in the darker alternate universe, Carson wanted to emphasize the toll that decades of war had taken on the crew and the bridge. "Picard really looked tired and worn and like a battle-weary commander, and that's what we wanted the bridge to look like—a battle weary bridge. I had lots of thoughts about making it as strong as possible using a lot of low lights, a lot of dark blues, making it very much more moody", he said. To heighten the impact of the physical set changes, Carson took a different approach to how he constructed shots. "It was my intention to make it as much like a submarine as possible and to use low-angle lighting; basically, to do everything the opposite way that the "Enterprise" was normally shot." The cameras were equipped with longer lenses than usual in order to reduce the depth of the scenes and provide a grittier feel. The use of low angles forced the lighting to be modified to prevent the scene from, in Carson's words, looking "like a hotel lobby".