I appreciate the replies to this question, but I’m not sure people understand what I’m getting at. It’s very simple, and relates to film very easily.
In film:
Shoot 24 fps and transfer via telecine at 24 fps to 30 fps video (60i). (Ignoring the .1% slowdown) To do this, you add an extra field every two frames, so you have five fields for every two frames of film.
Shot 30 fps film and transfer via telecine at 24 fps to 30 fps video. As far as the telecine is concerned, it has no idea what frame rate the film was shot at, so a 24 fps transfer of this footage will still add that extra field every two frames, in effect slowing down motion by 20%
On video:
24P Standard Def video cameras add the 3:2 pulldown for you (no telecine needed!) to get to 30fps (60i) video.
30P Standard Def gives you 30 progressive frames that are displayed interlaced in 60i. If you add that one field per two progressive frames, you’ll have exactly the same look you would with film shot at 30 fps and transferred at 24 fps in telecine. Hence, 20% slow motion.
All that said, I know there’s an easy way to do this in After Effects. I just need to know what it is!
Thanks again,
Chris
Chris Freilich
Cinematographer
Virtuoso Films
https://www.virtuosofilms.com