Job is correct – basically SMPTE does not define an NTSC format at 23.976 or 24 frames per second. So from a metadata perspective, 30fps NDF or DF represents the video format being captured while the actual media is native 23.976 for editing. 1080p on the other hand does have a 23.976, and 24 defined by SMPTE. 720p behave like NTSC again.. SMPTE.
But working in NTSC 23.976 still allows you to track 24fps timecode in two dedicated columns – you can derive the 24fps based on the START and Pullin columns by doing a command-D or control-D of the START timecode column and selecting TC24 or AuxTC24 from the pop-up column. MC will not track both timecodes. It will also track 25fps, 30fps with no pulldown, PAL with pulldown, etc. basically representing any type of format that might have 24fps on it – whether it is native or not.
Once HD hit the market and there was a 23.976 and 24 defined, most “24p” projects gravitated towards towards those project types to have the 1:1 timecode relationship in the START column. DNxHD36 was added as the offline resolution just as 14:1 was for NTSC. DNxHD36 is roughly 3x the storage needs of 14:1 without about 10x the picture quality. 🙂
Michael