Latest post Thu, Jul 18 2013 8:42 AM by Job ter Burg. 3 replies.
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  • Thu, Jul 18 2013 2:17 AM

    • Steve Lewis
    • Not Ranked
    • Joined on Fri, Jul 12 2013
    • Goleta, CA
    • Posts 9
    • Points 165

    Export color shift

    Hi.

    Here is a link to a screenshot of my computer:

    http://postimg.org/image/mj0316fkz/

    Why is the exported video (left) so different than my record monitor in terms of color, contrast, saturation, etc...???  What should I do to export properly?

    The export was a Quicktime.  Why is it so over-saturated and contrasty?

     

    Thanks for any assistance!

     

    Favorite film:  2001: A Space Odyssey

  • Thu, Jul 18 2013 6:28 AM In reply to

    Re: Export color shift

    First, the footage in the source/record monitor is not corrected from legal 709 16-235 to full swing 0-255 computer display.

    Then it makes a difference how you export your Quicktime and to what. If you export anything with custom settings, meaning anything other than Same-As-Source or Quicktime Reference , you are using the Quicktime encoder, which is notorious for its gamma shifts, especially when using its ProRes and H264 codecs. A better way would be to Export either Same as Source or Quicktime Reference, then use a decent encoding application to convert to H264 (for instance, MC comes with Sorensen Squeeze, which has the x264 and Main Concept H264 encoders, both of which are superior to Apple's H264 gamma shifter).

     

    You my also want to read up on color levels during import and export:

    http://www.jobterburg.nl/Publications/601_709_RGB.pdf

     

     

    Media Composer Symphony | PT Ultimate | Win10 HPZ | OSX MBP | ISIS5000 [view my complete system specs]
  • Thu, Jul 18 2013 7:25 AM In reply to

    • Steve Lewis
    • Not Ranked
    • Joined on Fri, Jul 12 2013
    • Goleta, CA
    • Posts 9
    • Points 165

    Re: Export color shift

    Hi Job,

    Thanks for your help.

    I have a few questions...

    1) I imported as AMA then transcoded to DNXHD 36.  Would this affect the way Avid handles color information?

    2) What exactly do you mean by "the footage in the source/record monitor is not corrected"

    3) When I tried exporting the video again, this time with "709" checked in the export dialog (instead of "RGB") the colors looked much better.  Not EXACTLY like in MC, but MUCH closer.  Why is this happening?

    4) You suggested I use a QT reference file and then open that in Squeeze.  Can you explain that worflow in more detail, or perhaps point me to a tutorial/blog post explaining how to do this?  

     

    Thanks for your time and support!

    Favorite film:  2001: A Space Odyssey

  • Thu, Jul 18 2013 8:42 AM In reply to

    Re: Export color shift

    Steve Lewis:
    1) I imported as AMA then transcoded to DNXHD 36.  Would this affect the way Avid handles color information?

    That should result in transparent passing of any and all luma information, unless you change the default settings (it allows you to strecht from studio swing to full swing and vice versa).

    Steve Lewis:
    2) What exactly do you mean by "the footage in the source/record monitor is not corrected"
    Rec709 legal video lives between luma levels 16 and 235. On a 709 calibrated monitor or a TV, 16 will look full black, and 235 will look full white. On a computer monitor, 0 is full black, so 16 looks greyish, and 255 is full white, so 235 is not top white.

    Steve Lewis:
    3) When I tried exporting the video again, this time with "709" checked in the export dialog (instead of "RGB") the colors looked much better.  Not EXACTLY like in MC, but MUCH closer.  Why is this happening?
    That is explained in the document I linked to, in detail.

    Steve Lewis:
    4) You suggested I use a QT reference file and then open that in Squeeze.  Can you explain that worflow in more detail, or perhaps point me to a tutorial/blog post explaining how to do this?  
    Hmmm, fairly easy. Open Squeeze, choose Import File, add a preset (like iPhone under Devices), then open the preset and click the codec dropdown box and select the codec you prefer. You will need to do some testing to get things to look as you want them. Others on these forums prefer using TMPGenc Video Mastering Works or ProCoder or even Compressor. YMMV.

    Media Composer Symphony | PT Ultimate | Win10 HPZ | OSX MBP | ISIS5000 [view my complete system specs]
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