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Re: RE Heavywoks vs Avid Film Composer





>What I had heard was that lightworks "recreated" the 24 fps when creating
>the lists while Avid actually digitized with this information and it
>actually followed through the whole process.  What does this change?  I
>actually don't know, for I have never tried it, but I was told by some
>editors (and others) that it was a "safer" process.
>

Lightworks and Avid both derive 24 images per second from transfers with 3:2
pulldown by digitizing only one field of each video frame. In the case of
Avid, only field 1 is digitized. In the case of Lightworks, only field 2 is
digitized. By not digitizing the one video frame in a 5 frame sequence that
duplicates a film frame image, the original 24 images are recovered. In the
case of Avid, that means that the first field of frame 3 in the video
sequence (the third field of the "B" film frame) is not digitized. In the
case of Lightworks, it's the second field of frame 5 (the third field of the
"D" film frame).
The real difference comes in the playout, which is what you're probably
referring to. Avid only has one playout mode for 24 frame editing (in an
NTSC system). This mode creates an output that mimics a continuous piece of
film, with 3:2 pulldown inserted continuously from the beginning of the
piece to the end. This output will exactly match a video transfer of the
assembled film, accurate down to the field. It does not, however, match a
video online assembly from the dailies that were originally supplied.
Although the action will match, the cut points can and do vary by a field in
either direction. This is because in a video online assembly, all edits are
forced to field 1, unlike a transfer from assembled film where the edit
points will fall on either field 1 or 2, depending on the 3:2 sequence at
the cut point. Not to mention the fact that the 3:2 pulldown created by the
Avid on output is not necessarily the same, on a cut by cut basis, as the
original dailies transfer. Lightworks can also output in a film mode that is
identical to the Avid method I just described. But Lightworks also has an
"online" output mode that correctly re-inserts the 3:2 pulldown on a shot by
shot basis to be accurate to the original dailies, and then forces every
edit to field 1. This output matches a video assembled version that uses the
Lightworks supplied EDL. Although I personally prefer Avid for reasons
unrelated to this one feature, I have long wished that they would create an
"online" digital cut mode for those programs that are finished on tape.

Mike Most, Encore Video, L.A.



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