7d Slow Motion Tutorial

March 28, 2012

I recently had to convert a lot of footage from 60 fps to 30 fps so that the footage had a nice slow motion look. It turned into quite a process. The original footage was shot on a 7D at 720p/59.94 and we were finishing 1080i/59.94 for broadcast. I used Avid to convert it.

Here’s the process-

1. Create a 720p/59.94 project in Avid 5+

2. AMA the source footage.

3. Create a sequence of the AMA clips (video only, no audio). Add 10 seconds of black between each clip.

4. Mixdown the video to DNxHD 145, and lift out each 10 second break.

5. Subsequence each clip from the timeline until you have a sequence for every clip.

6. Export the sequences from Avid; Same as Source, Use Avid Codecs, Video Only, RGB, 601 non-square.

7. If you want every fourth frame duplicated in the final product, open a 1080p/23.976 project. If you don’t, open a 1080p/29.97 project.

Most of the footage on our show was shot 24fps and converted to 30fps for broadcast. Since the slow motion shots were intended to be mixed with other 24fps material, we added a pulldown look to the shots where every 4th frame was doubled, by processing the clips in a 1080p/23.976 project, and then bringing the footage into a 29.97 project after that.

8. Open the Avid console, type “ignoreqtrate true”, and hit enter.

9. Change the import settings; Image Sized for Current Format, Computer RGB, Ignore Alpha Channel

10. Change media creation settings; DNxHD 145 or DNxHD 175 (depending on project type)

11. Create a new bin and import the quicktimes that were exported.

Depending on your system, it will probably take 10 times longer than real time to import! I recommend trimming one of the quicktimes in Quicktime Player to 5 seconds and import that to make sure the settings are correct before importing everything.

————————————————————————————–

If the footage was imported into a 29.97 project, then you’re done. If it was brought into a 23.98 project, but you are finishing 29.97 and want the film look on the footage, then another two steps still need to occur.

1. Output the quicktimes again! Either export them as quicktimes, or put them on an XDCAM disk, or some other type of deck that will create 24fps tapes as well as add pulldown so the tapes can be digitized into a 29.97 project.

I chose to export them to XDCAM using the Sony PDW-F1600 deck. This added the film look. It also allowed us to digitize at a lower resolution, and made upressing later very easy.

2. Digitize or import the footage into a 29.97 project. If you chose to create quicktimes and need to import those, then go to the console and type “ignoreqtrate false”.

And here’s a video I created using this technique-

If you have footage to convert and not the time or means, I’m available to work. Check out my services and contact info here.

-Matt Rittorno

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