All about Leica Reels
Of special interest (well, to me, at least) is the fact that the Leica reels could be advanced not only by hand but also automatically using a separate roll of film that ran real time in sync with the Leica Loop reel which had just one exposure per separate image. It also allowed for automatic sync with audio dialog and effects tracks!
The four consecutive Leica reels that I shot of the Anna & Bella storyboards that my old mentor Børge Ring had prepared were basically identical... Except that I shot them on 16mm, and projected them with a little toy silent hand-swing projector that only had seen Mickey in Arabia pass through it since my early childhood, onto a sheet of drawing paper pinned to the beams in Børge's attic work-room wall with two push pins. Four days that changed the film - and our lives... Anna & Bella won the Academy Award in 1986.