bfilm showed the Anamorphic format, (their have been a few variations. that actually does use a bit more film area per frame whicl sticking to 4 Perf Pulldown. the reason is that when Sound was added, the entire frame shrunk to keep the same aspect ratio and so the unused area between images was incresed. Anamorphic can allow the frames to have the interframe spacing that existed in the days before Soundtracks as the image is stretched vertically on the film, and then stretched back horizontaly to make for a wider screen. The first Process using the method was CinemaScope. exclusive to 20th Century Fox. CinemaScope used print film with special smaller perforations (called CS Perfs) which becase the process was exclusive to fox were sometimes Dubbed "Fox Holes" this allowed room for a sound track. The Robe in September of 1953 was the first CinemaScope release.
the one that still folks might relate to is VistaVison (tm) Motion Picture High Fidelity..
https://en.wikipedia.org/wiki/VistaVision
the format transports the film Horizontally like IMAX, with a Pull down of 8 Perfs, the same as our still cameras. While only a few full movies were released in VistaVision, it is relevant in Special effects like the early Star wars Movies.
the next step before IMAX is 5 Perf 65/70 mm (65mm Negative printed on 70mm perfed to match 65mm stock) again to allow for stereo sound.
IMAX uses 65mm/70mm with 15 perf Pulldown, and to get that to work there was a LOT of shredded film until they came up with a working transport.
at the other end of the film format scale, the wikipedia article on 16mm film still shows this picture of three of my dogs who have sadly passed on
https://en.wikipedia.org/wiki/16_mm_film#/media/File:16mmBWrevDP.png