[charles maynes]

Originally Posted by hociman

It should be noted that 23.98 (or 23.976, depending on what manufacturer it is) has no drop-frame option because of the integer number of frames.

At 29.97 non-drop timecode, there are 107,892 frames in an hour. At 29.97, you lose .03 frames per second in your count, which equates to 108 lost frames in an hour. If you drop frames on every minute except the 10th, you drop 2 frames * 54 minutes = 108 frames. The difference in the number of frames over the course of an hour between non-drop and drop frame timecode (108) is an whole number which makes the impementation of dropped frames practical in that it can represent clock time.

At 24fps timecode, there are 86,400 frames in an hour. At 23.98(.976) timecode, there are 86,313.6 frames in an hour. The difference here is 87 frames (rounding down) or 88 frames (rounding up). The point is there is rounding involved, so there is no whole number relationship, thus negating the ability to drop frames and get an accurate clock time on the content. If anyone says they are working at 24 drop, they are not correct.

J-

Since this is a digital format, wouldn't frames be arbitrary? There is not a real "frame" in digital, because it is a continuous capture.
Since dropframe was something introduced by the necessity of converting film to video, and the inability of the NTSC format to actually run those frames against the same reference as film, the drop frame counting method was a convenience for TV production to time out their programs to match real-time. The penalty of having the material play slow was seen as a necessary compromise.

This is an academic point btw...


cm