24p vs 29.97 project settings for film

[laura android]

Hello,

This is my first post on this site and I am in desperate need of assistance. I had the college Avid tech set my project up and I'm afraid it was done wrong. I am 20 minutes into the cut and noticed a jittery motion blur effect on the images, especially the moving ones. At first I thought it was just the 28:1 ratio that I captured at and that it would be remedied by uprezing the files to 1:1. However the problem still remains. I was told it could be a cadence problem but after changing the cadence letter and batch-capturing the problem was still evident.

I shot on S16mm and telecined to Digi-beta at 29.97fps. We had high hopes of perhaps going back to film so we set up the Avid symphony project to 24p:16mm. We did not import the flex files which I think was a big mistake. The images are pulling down on the wrong frame or something and it looks horrible.

So, my question is: Is there anyway to salvage the existing sequence I have created within this project. Can I create a new project with 29.97 and batch import the sequence. I am trying to avoid re-cutting 2 weeks worth of work so any suggestions would be greatly appreciated. THANK YOU...

 

[Kim Welch]

I apologize for the delay in responding, and thank you for posting. What you're describing sounds like a pulldown problem. Film shot at 24 fps and transferred to 29.97 video has a 3:2 pulldown pattern, and if the Avid doesn't know where the pattern starts (the A-frame), it removes the wrong fields, which causes exactly that jittery, stuttering motion.

The fix is to recapture with the correct pulldown phase for each tape, ideally using the telecine log (the FLEx or ALE file), which tells the Avid where each A-frame falls. The film transfer house can usually help with this. Today most film is scanned to files at native 24 fps, which avoids the problem entirely. For more help on post workflows, our Editing & Post-production forum and the on-demand classes at https://studentfilmmakers.com/courses/ are a good place to start.