[tig] 25fps sync film w/aatoncode to NTSC at 25fps?

dhamme at nyc.rr.com dhamme
Thu Jun 17 16:38:14 BST 2004

Okay, here it goes.

First, my obligatory statement that this is my first posting to the TIG after many instructional years of lurking. 

It seems that the conventional wisdom here is that this is a safe place to ask questions, and that there are no stupid ones. I have never posted primarily because I have been somewhat intimidated by the general knowledge pool that exists here, and not wishing to be vulnerable and reveal my own folly. I also have been intimidated by some responses by the very few users who appear to revel in aggressively ?correcting? others. In this case, I really need your collective reflection / instruction / correction, so the time has come for me to stop ??remain(ing) silent and thought a fool??. Time to ??speak up and remove all doubt.?

Specifications Scenario:

- film shot at 25fps with aatoncode
- sync sound recorded at 25fps

Delivery specs:

- transfer film to NTSC video at 25fps with sync sound  (aaton chase mode ? no claps)


Is this request strictly possible? 

Have any of you done similar jobs?

What are the pitfalls / areas of special attention / drawbacks?

My experience with this job is as follows;

-film transport was set at 25fps varispeed.

-when playing film (no audio sync) it would consistently lock at 24.97/8 ? flickering between the two. (I accepted this as normal, thinking that it corresponded to the .01% NTSC speed reduction. True/False?)

- When syncing, film would ?lock? at 24.97/8 and appear to be in sync. (In areas of audio track with music, a slight variation in pitch could be detected audibly.
- On other occasions, the film would lock at 23.98, and appear to be in sync.

In all cases when the transport would stop, the fps display would show that varispeed was still set to 25.00fps.

I transferred this job, and allowed both scenarios to go out to the client. I reasoned that because the client was not going back to film and the audio appeared to be in sync, coupled with the fact that I was alone on a weekend and turn around delivery was very tight, that the variations were acceptable. Wise or foolish?


- Were these variations inherent in the execution of this job?
- Was this a matter of Operator Error? Please explain.
- Is there any reason to suspect equipment error?

I don?t know if I have enough background with similar scenarios to properly evaluate this issue. Should I be confident in my evaluation, or do I need to learn something here?

Your collective thoughts on this matter would be greatly appreciated. 

Thank you,

David Hamme

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