Frame counting

[Born Under Punches]

So I'm watching the new DVD for Purple Rain this week and listening to the commentary featuring Albert Magnoli.  During the scene before the Computer Blue number, Magnoli mentions something about frame counting and how he used it (he was the editor as well) mentioning that he used 3, 7, 21 and how he learned it while attending USC from George Lucas who apparently used 4, 8, 12.  Could somebody pull a Philadelphia and explain this to me like I'm a three year old.  What is frame counting?

[SHAFTR]

So I'm watching the new DVD for Purple Rain this week and listening to the commentary featuring Albert Magnoli.  

Is the commentary good on Purple Rain?

[Born Under Punches]

pretty good actually.  alot of it is magnoli talking about how prince carried a purple notebook and scribbled ideas and how no one thought the movie would be so popular (mainly warner brothers who didn't have that much faith in the first-time director and three new producers.)

[bonanzataz]

Could somebody pull a Philadelphia and explain this to me like I'm a three year old.  What is frame counting?

NOW i know where i got that line from. i say it all the time and knew it was from SOME movie. now i know. thanks.

[subversiveproductions]

I'm probably way off on this, but I believe that has something to do with rhythm, whether of the music or just the "beats" of the film.  Like I said though, I'm probably way off.

[pete]

it's editing related, it's how your editing platform counts the frames when you run the film footage, and I assume the 4 - 8 -12 and 3 - 7- 21 are ways the numbers are divided.