Important Issue Involving Sony FS7 Footage and Avid

For Sony FS7 users who also edit in Avid, you might want to pay careful attention to this issue that I noticed a few weeks ago. After shooting some exteriors of the hospital here at St. Jude, I ingested the footage into Avid and then began color correction and grading. That's when I saw this:

Notice the banding and artifacts throughout the sky. I checked other shots from the same day. The bands and artifacts were present in every shot. So I went to the archive and looked through footage I captured months ago and the banding was also present, even on uncorrected and ungraded footage. I just never noticed it before. 

In comparing all of these shots, it was obvious that the symptoms appeared whenever a smooth, solid-colored object was in the frame: the sky, a blank wall, a gray curtain, etc. It also quickly became apparent that the issue presented itself regardless of the codec or resolution settings used on the FS7: XAVC-I, MPEG 422, 4K, UHD, 1080p, etc. It also didn't matter whether I recorded to the card or to an external recorder, like the Atomos Ninja.

The root cause of the problem is how Avid handles the media coming off of the card or external recorder. To work with FS7 footage in Avid, you might have to tweak your workflow a little bit. Here's how to do it:

  • Since XAVC-I is a 10-bit codec, you cannot transcode the footage to Avid DNxHD 145, since that is an 8-bit codec. You have to transcode to Avid DNxHD 220x and ingest that footage into your project. DNxHD 220x is also a 10-bit codec, which will match the depth of the footage off of the card.
  • The Avid sequence should be set to 10-bit monitoring. You can toggle to 10-bit mode by looking at the bar on the bottom left of your sequence window and making sure the green oval has a "10" in the center. If it doesn't, click the oval until it appears. It looks like this:
  • Now your FS7 footage will look clean after ingesting and also during the edit. But if you export a master ProRes 422 file out of Avid, the banding and artifacts will reappear. You will need to export a QuickTime reference file out of Avid first. Take that file into Media Encoder and master your ProRes file there instead. Then you will have a clean image from acquisition to export.

Do you have any other workflow tips and tricks for Avid users? What does your workflow look like when using the FS7? Leave your thoughts in the Comments section below.