"White Christmas", "Strategic Air Command", "To Catch a Thief", "Richard III", and "The Battle of the River Plate" had very limited (two or three) prints struck in the 8-perf VistaVision format in which they were shot. Although the clarity of these 8-perf prints was striking, they were used only for premiere or preview engagements between 1954 and 1956 and required special projection equipment. This exhibition process was impractical because for the footage to travel through a projector at the normal 24 frames per second, the film had to roll at three feet per second, double the speed of 35 mm film and causing many technical and mechanical problems. Aside from these prints all other VistaVision films were shown in the conventional 4-perf (vertical) format, as planned.