its nearly 50 odd years since the great mans 4 minute mile.with the technology we have nowadays,is it possible to retime the event using the archive film?i would imagine they used a stopwatch back then.
the way to determine the film speed would be to run the film and keep adjusting the projector until RB crossed the tape 239.4 seconds after he set off (?)
Even if somehow you could time is amazingly well using the footage, you'd still have parallax errors (most likely, I haven't seen the footage) and the like.
i think the point rojash is trying to make is that you could only set the film to 239.4 secs if you were sure thats exactly how quick he ran it which brings us back to the op's question.