Technology & Internet

What was the fastest slow motion camera in 1950s?

In 2020, fastest slow motion camera is 70 trillion fps. However I doubt we will be using it even 50 years later as ordinary citizens.

In 1950s, I am guessing there were cameras that could record faster than our smart phones can do today.

I watched nuclear some bomb test videos from 50s made by US goverment and they look very slow motion.
What was the fastest slow motion camera in 1950s?
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