New Motion Picture Apparatus: Mirror Telephoto System
Journal of the Society of Motion Picture Engineers · 1933
The problem of gaining “distance” in motion picture photography, in contradistinction to that of achieving close-ups, has led to the development of telephoto objectives. When it is required that the focus be increased to a large extent, and if the aperture be kept within the usual range, the length of the required attachment and the diameter of the Front lens become rather impracticable.