Anybody here remember Douglas Trumbull's Showscan system?
Remember it in theory but never saw it. Hard to imagine the projector not tearing itself apart but very cool concept. Met Trumbull when he was doing pre-production on Brainstorm.
Along the lines of ambitious formats, in the 80's I did see Coppola's restoration of Abel Gance's 1927 Napoleon where it was three screens side by side (outdoors) for the climax battle scenes (plus Carmine Coppola conducting live orchestra). Pretty amazing.