Increase in program length between 23.98 and 59.94

[Gary Adcock]

[Rob Gardner] “Does anybody know the formula to predict the increase in screen time that occurs when going from FCP material shot on the Varicam at 23.98 to 59.94 for the air masters”

What platform, OS, NLE and hardware versions? (different rules apply depending)

you are accounting for 23.98 to be NDF and 59.94 to be DF.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

[Rob Gardner]

The patform is a Mac dual gig G5, running OSX 10.4.8 and the most recent Final Cut Pro. The workflow was from the original Varicam tape, shot at 720p into the Mac for editing, then out of the Mac by firewire to tape on a Panasonic 1200 at 720p 23.98 and from there to an HDcam deck, upconverting to 1080i at 59.94. (I think that’s correct). The HD masters are delivered to PBS on HDcam. None of my clients will accept a 720p master so everything has to go up either to D-5 or to HDcam for delivery.

This also happened when going to D-5 on another project. I’m a producer, not an editor, and I find understanding this process pretty complex.

But this problem of the small expansion of screen time has happened before and either we are doing something wrong or it is inherent in the process. I don’t remember seeing any other posts on the subject. Maybe there is a step we are misshandling or maybe there is a formlal for calculating the difference in final screen time so that it could be accounted for during editing (making the show shorter by a pre-determined amount of time, so that it will expand into the correct network spec for program length).

Any help or observations would be appreciated.

Thanks

[Gary Adcock]

[Rob Gardner] “This also happened when going to D-5 on another project. I’m a producer, not an editor, and I find understanding this process pretty complex.”

Then you need to have someone explain the difference between Drop Frame and NON Drop Frame time.

they are different as I said– 24p video is always non drop, so by playing that out on a 49.94 drop frame time line it will play out longer – it has more frames.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

[Rob Gardner]

Thanks, though while I may be easily confused about drop frame, it would be odd if all four of the experienced editors working on two different broadcast projects and the guys in the on-line house didn’t.

I think there is more to it.

But you never know…

[John Sharaf]

Rob,

24p has brought a lot of required new learning to both the production and post-production realms; it takes a while for everyone to come up to speed, this is a perfect example, as you now know that there is no such thing as drop frame in 24p, so the time code does not act as clock code in this format, yet most if not all programs are delivered in DF mode for this very reason.

For us to now learn from your observation that what we’re talking about is 3.5 seconds per hour provides a guideline for which we can make the necessary adjustments in the future, thanks for your inquiry, we’ve all learned something new about 24p HD production. Obviously this applies to both DVCPRO100 and HDCAM formats.

[Frank Nolan]

Now that you have cut 7 seconds off your credits to make the show the correct length for wall clock time, all your breaks for commercials will probably be in the wrong place. (That’s of course if you were given specific times for breaks to occur). What your editors need to have on hand while working in NDF but delivering in DF, is a timecode calculator for converting between NDF and DF. That way if the network wants you to deliver a master with a commercial break occuring at 1:13:10:08. You can punch that number into the calculator as DF and it will convert it to NDF and let you know the corresponding NDF TC number. This is not a new problem with 24p material. Editors have been dealing with this when cutting material digitized at 29.97NDF for years.

[Frank Nolan]

[Rob Gardner] “But this problem of the small expansion of screen time has happened before and either we are doing something wrong or it is inherent in the process. I don’t remember seeing any other posts on the subject. Maybe there is a step we are misshandling or maybe there is a formlal for calculating the difference in final screen time so that it could be accounted for during editing (making the show shorter by a pre-determined amount of time, so that it will expand into the correct network spec for program length).”

There is not really any expansion in screen time occurring during the transfer process. It is already there in your original edit. To check this you could start a stop watch at the head of your show and by the time you get to the end you will find your stopwatch reads 1 hour and 3.6 seconds. Or your show will be 108 frames too long. NDF timecode DOES NOT accurately reflect “Real time” that is why they invented DF timcecode.

[Paul Thurston]

Does anybody know who makes a NDF (non drop frame) time code to DF (Drop frame) timecode calculator and who would sell such a product? I’ve always needed one?

-Paul

[Mark Raudonis]

[Paul Thurston] “Does anybody know who makes a NDF (non drop frame) time code to DF (Drop frame) timecode calculator and who would sell such a product? I’ve always needed one?”

Type: “Time code calculator” into Google and you’ll get a dozen suggestions.

Mark

[Paul Thurston]

Hi Mark,

Thanks for the tip. I found excellent software that accomplishes the task.

Here