Henry Spencer wrote:
It really is a sin and a shame that IMAX didn't exist quite early
enough
to film a Saturn V launch...

Now that you mention it, I seem to recall that the IMAX film "To Fly"
did have a Saturn 5 launch. It was shot from a pretty good distance,
several miles. As the scene progressed the IMAX footage was
supplimented with a lot of the familiar 16mm film taken from Saturn 5
rockets of the interstages falling off. (Of course, the 16mm stuff was
way too grainy to blow up to a full frame. It was incorporated with
'Grand Prix' style split screen effects.)

-Mark Martin