Slow motion to match lip synching singer

[rbg]

Hey-

 

This is my first post. I've been reading for about 6 months and have learned so much, so thanks

to everyone who has posted, I shall try to do more of it myself.

 

My question is: If I shoot a singer in slow-motion, say 48 fps in 16mm, how fast do I need to speed up

the track they're singing along with, so that it looks like they're singing at a regular speed, even though

they're moving in slow-motion. I've heard of a sacred ratio, but couldn't find it in the postings or anywhere

on line. The shoot is a spec music video for a friend, short-ends, fun, experimentation, learning, etc....

 

Thanks again.

 

RBG -

[Michael Collier]

Well, if playback will be 24fps, then you would speed the song up by a factor of two. The singer would have to be able to lip sync to the song at that speed.