Just got a batch of high speed 60fps clips (not 59.94), already slowed down and as 23.976, ready to edit. Production also was rolling sound on this high speed, thinking they might want the option to speed up the footage to real time, and use the same clips with audio as well.
I am currently adding a 250% timewarp to these clips, and syncing with the slates provided. Going pretty smooth. Trouble is, as expected, drift is slowly creeping its way in as the clip plays out. The good thing is the clips are very short, some less than a minute, at most 5 minutes. For the longer clips, I'm having to find an edit point, and just slip the video back a couple frames, and eyeball the sync.
... Not an ideal process.
Any suggestions for me, or the production dept next time we try this? If we chose to shoot in 48fps (47.95), and if I sped up the ftg to 200%, would the sync be without flaw? Is this drift happening becuase we are editing ins 23.976 and not true 24p?