Why shooting 720p instead of 720pn

[cane]

Can somebody tell me why I would shot in 720p instead 720pn.
I know whow 720pn works and it save more record time on mine p2 card.
But when will I get needed to use option 720p.

Is there a secret quality difference between these two options.??

[Barry_Green]

No quality difference. 720P is for firewire compatibility with decks and firestores. Or, for recording variable frame rates and audio at the same time.