How many mm of 35 mm film sound?

[Vivaldi]

70 mm film has 5 mm sound. So it is 65 mm for views.

How about for 35 mm?

[WindAtMyBack]

To my knowledge, 35mm film is 35mm picture. You used to be able to buy 35mm movie film in large rolls to use in regular still cameras (you cut it to length). It was just like other 35 mm film like Kodachrome. I never used it myself but I knew people who bought that stuff because it was high quality film and cheaper than single roll film.

I looked it up. With 70mm sound film, the sound part used some of the 70mm film. With 35mm sound film, the sound was between the perforations, so it didn't subtract from the picture part of the film.

[WindAtMyBack]

I don't know much of the history, but I wonder how common sound film was. I always thought that the video and sound were recorded separately. I remember watching movies at the theater when I was young. It was common for the video and audio to get out of sync. I'd guess that happened in close to half the movies I saw.

The guy running the projectors would sometimes stop the movie to sync the sound. It was something we just had to put up with. we also had to put up with the film coming off the track and the video going haywire.

I worked on the design of some of this stuff in the late 90s. Digital tech was just getting fast enough that the video and audio could be recorded on hard drives separately. On playback, they could be synced perfectly. But that required the fastest hard drives available at that time. We used something similar to duel SCSI drives, with the video split between the drives so it could record and play back faster.