Is 23.98 always 23.976 in disguise?
by jack westburg
on
Jun 26, 2008 at 10:13:53 pm
Does the "23.98" frame rate even exist?
Is anything truly shot/captured/rendered as 23.98?
You may answer "yes of course, just look at the Clip info in final cut, your sequence setting, or movie inspector in quicktime - it says 23.98!"
I have a self taught background and I've tried to research this as much as possible - books, web, colleagues. The more I work in video the more I get the impression every display in every program on every VTR that says "23.98" is just abbreviating "23.976"
Is there any truth to that statement?
Is a 23.98 FCP Sequence actually 23.976?
Is the 23.98 setting on the DVW-D2000 actually playing/recording at 23.976?
This frustratingly confusing when an app comes along like After Effects that will actually let you make a comp that is any frame, including 23.98 and 23.976.
(a 23.98 render from AE will have frame jitter when played in a 23.98 sequence in FCP and eQ)
Re: Is 23.98 always 23.976 in disguise? by Reid Caulfield on Jun 27, 2008 at 3:05:26 am
I believe 23.98 is shorthand for 23.976. The more important question is, if this is NOT the case - if they ARE different things, in other words - is there rounding going on. My inclinations is to say that this is not the case. Actual rounding would be mathematically disastrous, especially on long shows. Presume 23.976.
Re: Is 23.98 always 23.976 in disguise? by Jeremy Garchow on Jun 27, 2008 at 4:36:38 am
You are teaching yourself well. 29.97 is really 29.970. If you enter 23.98 in any other program other than final cut, it will mess up your movie as it should really be 23.976 and that includes Quicktime. But you already know that.
23.98 just rolls off the tongue a bit better I guess.
Re: Is 23.98 always 23.976 in disguise? by Reid Caulfield on Jun 27, 2008 at 5:40:39 am
Though I haven't tried it in awhile, and being as how my main audio environment of choice is Nuendo (as opposed to Pro Tools, which I also use), I remember the first time I did a "23.98" project in Nuendo. Slight drift all the way through due to the discrepancy, but there was no other choice, as I recall. The app allowed for entering a rate in the field but wouldn't go more than 2 decimal places. Resulted in me having to do cuts every minute or 2 & move audio by subframes to keep absolute sync. They seem to have fixed it. That's the kind of havoc the second & third decimal places can play. Thanks for the affirmation of the 23.98/23.976 question.
Re: Is 23.98 always 23.976 in disguise? by Peter Kiwitt on Jun 28, 2008 at 1:03:31 pm
I believe that 23.976 is also a rounded number. For simplicity's sake we calculate 24-.024=23.976 and 60-.060=59.94 but the actual formulas are 24x1000/1001=23.976024 and 60x1000/1001=59.940060. So 23.98 can be seen as the correct frame listing to round all rates from six decimal places to two.
