Any other thoughts from anyone?  Been looking for an answer but it seems to either be a DNxHD issues or Premiere issue.  I really don't want to use gi-normous uncompressed files for intermediates.

I just thought of this.  Perhaps the aspect (1920x817) is throwing it off?  I'll test it tomorrow.

Okay after some troubleshooting, I narrowed down the problem to the Gaussian Blur effect.  This is indeed marked as a 32-bit effect, but it seems when exporting to DNxHD (I haven't tried any other codecs), it clamps to 8-bit.  The clamping doesn't happen within Premiere though (when I add Gaussian Blur AND extreme contrast to the clip on the timeline), only when the video is exported.

Screenshot #1: Added Gaussian Blur, exported to DNxHD (again above settings), imported into Premiere, Added extreme contrast using fast color corrector.

Screenshot #2: No effects, exported to DNxHD, imported into Premiere, added Gaussian Blur, added extreme contrast using fast color corrector.

Averdahl wrote:

 

Richard,

 

I would have un-checked "Render at Maximum Depth" in the Export Settings dialog and try again. You have already specified 10-bit in the DNxHD Codec configuration so i see no need in then telling Pr to render out to 24-bit by using the "Render at Maximum Depth" option in the Export Settings dialog. Maybe that's the problem, telling the exporter to do 10-bit via the codec configuration and at the same time tell it to do 24-bit via the Export Settings. (I would have skipped the "Render at Maximum Depth" no matter what when going to DNxHD.)

 

If the problem persists, place the media in a 1920 x 1080 timeline and render out to 1920 x 1080. Maybe DNxHD cannot handle non-broadcast frame sizes.

 

If the problem still presists, try another codec to see if it is a codec related issue or not.

 

/Roger

Roger...looks like we posted at the same time.  The issue was the Gaussian Blur effect.

Yes, but maybe the issue goes away if you do un-check the "Render at Maximum Depth" when you use the Gaussian Blur.

Just went and tried it.  Unchecked this option and still was banded.

What version of Pr?

GPU Acceleration on or off?

Can you post a screen shot of the Timeline?

Version 6.0.1

MPE enabled

Screeshot:

Another theory...it's a CS6 bug.  (Been using it for 2 weeks and there are ALOT of strange little bugs)  I'm going to do the same test in 5.5 and see if the problem exists. 

Okay I just tried the expirement in CS5.5 and it has the same problem.  I also tried exporting to DPX to see if it occurs on that type of file and it did NOT have the problem.  So far it's only limited to DNxHD.  I'm going to try more variation in the Avid codec settings and see where that gets me.  Perhaps encoding to the higher bitrates/framerates.

Averdahl wrote:

 

Can you post a screen shot of the Timeline when you have all filters on the clip, ie a screen shot from the Timeline you are exporting from. (I should have been more clear.)

 

/Roger

I don't understand.  You mean a screenshot of the effects controls panel?

Okay another update.  I pulled in some other shots...and it does appear to be the codec and NOT the Gaussian Blur effect.  The fault in my testing was that I was applying the blur after importing the exported DNxHD file and hereby obliterating the banding.  The new clip I'm testing is a shot of a wall with the lens out of focus, creating a nice, smooth gradient to test with.

Here's my updated test:

Screenshot #1: Exported to DNxHD, imported into Premiere, added extreme contrast using fast color corrector.

Screenshot #2: Original clip, added extreme contrast using fast color corrector.

EUREKA!

Found out that the clamping occurs when certain bit depth options are selected in the export panel.  Apparantly when 24bit or 32bit is selected, it clamps to 8bit.  But when 48bit or 64bit is chosen, no clamping occurs.  I wonder if this is limited to DNxHD or not.