I recently watched a video of Led Zeppelin in 1973 and it dawned on me that these were shot on film, and as a film photography hobbyist it dawned on me that the picture quality for handheld film at a low-light concert is pretty good, or at least significantly better than what I could accomplish with my 35mm SLR. How was it done? Was it shot at some insane aperture like f/1.0, did they use special film, or was the stage brighter than what I'm expecting?
Video in question: