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  • Sun, Jun 16 2013 7:03 AM

    • othila
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    The old, Quicktime gamma shift question-Confused

    I have moved from FCP7 to Avid MC5.5.2 and I have read as much as I can find on the net about this gamma shift and yet I'm still confused after many tests.  I work with FCP7 editors but my choice is Avid.

    Here we go: 

    1. AMA Canon C-LOG C300 straight form the card, transcode to DNX 185, edit footage-Export 601/709 to quicklime Prores 422 HQ.

    Result in FCP7 -  footage is washed out- Gamma shift.

    2. AMA Canon C-LOG C300 straight form the card, transcode to DNX 185, edit footage-Export RGB to quicklime Prores 422 HQ

    Result in FCP7 - footage is gamma correct.

    I forgot to mention that I'm on a MAC and have a Flanders Scientific monitor connected for colour correction both on FCP7 and Avid.

    I have researched this and done tests and still do not understand.

    Any solutions yet?

     

    Avid Media Composer 8.3.1 Matrox MX02 on MacPro4,1 Quad-Core Intel Xeon 2.66 GHz, Memory: 16 GB, OS 10.8.5, NVIDIA Quadro 4000 [view my complete system specs]
  • Sun, Jun 16 2013 7:58 AM In reply to

    Re: The old, Quicktime gamma shift question-Confused

    The thing is that the Quicktime ProRes export causes these shifts. It's nothing inside MC, unfortunately. As soon as you use Custom QT export settings, you are using QT to do the conversion.

    If you upgrade to MC6.5 and IF you work on a Mac, you will be able to work with ProRes natively. Meaning that in stead of transcoding to DNxHD, you would transcode to ProRes (you will still have MXF files in your MediaFiles folders, but they will now be MXF-wrapped ProRes). Then, when done editing, you can export using Same As Source. This bypasses the QT encoder, and simply wraps your ProRes footage into a QT container. This bypasses any of the gamma issues.

    Unfortunately, Mac-only, as Apple won't allow any parties to create ProRes media on non-Apple platforms. Which is one of the two main reasons that the industry should never ever have so widely adopted ProRes to begin with. The other main reason is the uncontrollable gamma.

    If you upgrade to MC6.5 now, you will get a free upgrade to MC7 when it is release (probably at the end of this month).

    Media Composer /w Symphony option | PT-HD | Win7Pro64 HP | OSX MBP | ISIS5000 | Nitris DX | Artist Mix & Transport & Color | AJA T-Tap | Decklink... [view my complete system specs]
  • Sun, Jun 16 2013 8:05 AM In reply to

    • othila
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    Re: The old, Quicktime gamma shift question-Confused

    Thanks for the reply.  I have been reading your paper on this, thanks for that.  There has to be some workaround as many Mac users must face this on a day to day basis.

    Even when I export to DNX 185 I seem to get a gamma shift.

    Very confusing.

    Avid Media Composer 8.3.1 Matrox MX02 on MacPro4,1 Quad-Core Intel Xeon 2.66 GHz, Memory: 16 GB, OS 10.8.5, NVIDIA Quadro 4000 [view my complete system specs]
  • Sun, Jun 16 2013 10:00 AM In reply to

    Re: The old, Quicktime gamma shift question-Confused

    othila:
    There has to be some workaround
    Actually, there is a solution. It is called MC6.5 ;)

    othila:
    Even when I export to DNX 185 I seem to get a gamma shift.
    Comparing what to what, exactly? If you are comparing an Avid import with an FCP import, all bets are off, as FCP in my experience does not necessarily maintain accurate color levels. For instance I have never been able to import the Belle Nuit test chart in FCP correctly (the one time I tried, but no one has ever been able to show me how to pull that off after that one time either).

    Altough it has to be said that AMA also has (had?) some bugs with color levels (on H264 sources at least), which is why, in general, I think File->Import at 601/709 is the cleanest method.

    The culprit, IMHO, is the buggy, bad, unprofessional Quicktime. I long for the day when those responsible for the mess that the combination of QT, H264 and ProRes have brought to our industry will have to stand trial.

    Media Composer /w Symphony option | PT-HD | Win7Pro64 HP | OSX MBP | ISIS5000 | Nitris DX | Artist Mix & Transport & Color | AJA T-Tap | Decklink... [view my complete system specs]
  • Sun, Jun 16 2013 12:15 PM In reply to

    Re: The old, Quicktime gamma shift question-Confused

    Job ter Burg:
    The culprit, IMHO, is the buggy, bad, unprofessional Quicktime. I long for the day when those responsible for the mess that the combination of QT, H264 and ProRes have brought to our industry will have to stand trial.

    You'll have a long wait.   The opposite is actually happening in the US.   Many local broadcasters are specifiying H.264 for transcoding commercial uploads.   Broadcasters that used to give the choice of several codecs now only accept H.264, which turns the concept of accute color correction and legal levels into a crap shoot!

    MC 2018.4 with Symphony, Matrox MX02 Mini Max, Win 7 Pro, HP Z800 2x6-Core 3.2Ghz Xeon, 48GB ram, Quadro K4200, SanDisk Extreme 240GB SSD as system drive... [view my complete system specs]

    I have a fantastic editing assistant.  He stays by my side when I edit...doesn't talk too much...and thinks I'm a genius!    Check him out here: www.youtube.com/watch?v=ZQVkYaaPO6g

  • Sun, Jun 16 2013 10:01 PM In reply to

    • othila
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    Re: The old, Quicktime gamma shift question-Confused

    So for me to hand over a finished edit to a client that needs a 422 HQ Proress that works on FCP7 I would export selecting RGB mapping 0-255.  This does not seem right to me but looks correct.

    My understaing is that 601/709 is the correct space for Video.

    Wow, my head aches.

    Avid Media Composer 8.3.1 Matrox MX02 on MacPro4,1 Quad-Core Intel Xeon 2.66 GHz, Memory: 16 GB, OS 10.8.5, NVIDIA Quadro 4000 [view my complete system specs]
  • Mon, Jun 17 2013 11:26 AM In reply to

    • othila
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    Re: The old, Quicktime gamma shift question-Confused

     

    Ok, I have done some tests and have read the PDF from Job ter Burg along with many post on this subject that it's so confusing.

    This is about as scientific I can get.   As you can see there are three grabs which have been exported out of Avid MC 5.5.2. To obtain the grabs I imported the clips into FCP and took a grab within FCP and then exported a grab to PNG.

    I have done this, this way as I know FCP and how it looks to my eye on a computer screen, TV and broadcast monitors that I own and use every day.

    I agree that there must be an issue with Quicktime and of course with the RGB export i would expect this result.  The one that I'm confused about is the DNX export.  Why is this export different from the 601/709 Prores export.

    Also there must be many editors out there on Macs that have this issue with supplying edits for FCP users.  I would like to hear from you and how you get around sending the correct gamma file to your client.

    Cheers 

     

    Avid Media Composer 8.3.1 Matrox MX02 on MacPro4,1 Quad-Core Intel Xeon 2.66 GHz, Memory: 16 GB, OS 10.8.5, NVIDIA Quadro 4000 [view my complete system specs]
  • Wed, Jun 19 2013 8:07 AM In reply to

    • othila
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    Re: The old, Quicktime gamma shift question-Confused

     

     

    Ok, I have done more tests and seems to hold up, I don't fully understand but its working.

     

    File footage: XDCAM HD 50Mbits (1080p/25)  This is from a Sony PMW 500

    AMA file via the AMA volume.  The folder is on a hard drive with the full structure in place.

    Transcode a file from this folder, I chose one clip.

    Export from Avid via: File, Export.

    Send To QT Movie

    Export as QuickTime Movie

    Custom - Format Options, Apple Prores 422 HO, Gamma Correction Automatic

    Video and Audio button selected

    Video Format 1920 x 1080

    Color Levels RGB

    Display Aspect Ratio - Native dimensions

     

    I have a Flanders Scientific LM 2461W monitor attached to my system via a Blackmagic card and a Matrox Mini.  This monitor has a Scope included for checking levels etc..

    When I export form Avid MC 5.5.2 using Color Levels RGB instead of 601/709  and bring this into FCP7 there is no gamma shift.  And when I AMA back into Avid there is no gamma shift.

    When I play both files with Quicktime 7 I get a slight gamma shift.  I can live with that.

     

    I'm not understanding any of this and why Exporting from Avid a RGB file works both as a file for FCP and as a AMA back into Avid.

     

    Avid Media Composer 8.3.1 Matrox MX02 on MacPro4,1 Quad-Core Intel Xeon 2.66 GHz, Memory: 16 GB, OS 10.8.5, NVIDIA Quadro 4000 [view my complete system specs]
  • Wed, Jun 19 2013 8:25 AM In reply to

    • othila
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    Re: The old, Quicktime gamma shift question-Confused

    I forgot to make metion that there is a very slight gamma shift and one that I can live with and it looks like the RGB export is also clipping the signal a bit.  When this is brought in FCP or back into Avid the gamma shift and cilp is so hard to tell other than looking at the scopes. 

    Avid Media Composer 8.3.1 Matrox MX02 on MacPro4,1 Quad-Core Intel Xeon 2.66 GHz, Memory: 16 GB, OS 10.8.5, NVIDIA Quadro 4000 [view my complete system specs]
  • Wed, Jun 19 2013 9:12 AM In reply to

    • othila
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    • Joined on Thu, Sep 29 2011
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    Re: The old, Quicktime gamma shift question-Confused

    I have done one more test this time using the Belle Nuit HD Test-chart which I should have done from the start.  Exporting from Avid a RGB Quicktime file results in the whites and blacks being clipping heavily so at this stage my theory is incorrect, hey at least I gave it a shot.  

    i'll stick with FCP7 I think as this gamma issue is to big for me to work out.  I need to hand files off to clients in the manner that I'm currently doing with FCP7.  I feel moving to an Avid edit only will result in my clients complaining about the quicktimes and how they look different on their system.

     

    Shame real as I like the Avid.

    Avid Media Composer 8.3.1 Matrox MX02 on MacPro4,1 Quad-Core Intel Xeon 2.66 GHz, Memory: 16 GB, OS 10.8.5, NVIDIA Quadro 4000 [view my complete system specs]
  • Wed, Jun 19 2013 12:25 PM In reply to

    Re: The old, Quicktime gamma shift question-Confused

    othila:

     

    I have done one more test this time using the Belle Nuit HD Test-chart which I should have done from the start.  Exporting from Avid a RGB Quicktime file results in the whites and blacks being clipping heavily so at this stage my theory is incorrect, hey at least I gave it a shot.  

    i'll stick with FCP7 I think as this gamma issue is to big for me to work out.  I need to hand files off to clients in the manner that I'm currently doing with FCP7.  I feel moving to an Avid edit only will result in my clients complaining about the quicktimes and how they look different on their system.

     

    Shame real as I like the Avid.

     

     

    Don't quote me as being 100% correct, but I'll share my insight if it helps at all:

     

    Import or exporting something as 709 is Avid speak for "don't touch the colors, keep them as is."  While importing as RGB means "squash a 0-255 signal into 16-235" and exporting to RGB means "take the 16-235 values and expand them into 0-255."

    This means that if you want Avid to keep your footage unchanged, you need to import and export as 709 (strange as that may seem).  

    Further more, I've noticed an extra issue when exporting prores from Avid.  Even if you export in 709, there is STILL a gamma shift.  I found the exact same issues as you.  Consequently I have avoided ProRes in my workflow for this precise reason.  

    The complcate things more, I actually saw a difference in how quicktime player would view the exported ProRes file versus how it would look inside FCP (inside FCP it looks fine.. but not in quicktime... if my memory serves me correct).  

    Anyway... there's my own addition to this annoying issue.  

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  • Wed, Jun 19 2013 1:28 PM In reply to

    Re: The old, Quicktime gamma shift question-Confused

    othila:

    need to hand files off to clients in the manner that I'm currently doing with FCP7.  I feel moving to an Avid edit only will result in my clients complaining about the quicktimes and how they look different on their system.

     

    Shame real as I like the Avid.

    A simple and easy solution is to ask your FCP colleagues to dowload the free Avid codecs.  Then you can export your project as same-as-source and they can import it into Final Cut.  My FCP colleagues have the Avid codecs on their system and I send them a same-as-source directly from Avid which they import into Final Cut with none of the gamma shift problems. 

    MC 2018.4 with Symphony, Matrox MX02 Mini Max, Win 7 Pro, HP Z800 2x6-Core 3.2Ghz Xeon, 48GB ram, Quadro K4200, SanDisk Extreme 240GB SSD as system drive... [view my complete system specs]

    I have a fantastic editing assistant.  He stays by my side when I edit...doesn't talk too much...and thinks I'm a genius!    Check him out here: www.youtube.com/watch?v=ZQVkYaaPO6g

  • Wed, Jun 19 2013 9:11 PM In reply to

    • othila
    • Top 500 Contributor
    • Joined on Thu, Sep 29 2011
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    Re: The old, Quicktime gamma shift question-Confused

    Thanks guys for your replies,

    I wonder why the techs at Avid has not replied on the gamma issue?  there are so many post on the web with this issue.  It would be great for someone at Avid to post a workflow for the people coming from FCP.  FCP7 is a fantastic NLE but it's now dead and I have to think about my editing future and I have always wanted to use The Avid.

    My problems are delivering stand along Quicktimes to clients that view these edits on their systems from Prores, h.264 and most of my clients wouldn't know what FCP is.

    For the editors that I deal with having the Avid codecs would help.  I have both FCP7 and Avid on my system and struggling to get things looking correct.

    Anyway one day a solution might turn up.

    Cheers

    Avid Media Composer 8.3.1 Matrox MX02 on MacPro4,1 Quad-Core Intel Xeon 2.66 GHz, Memory: 16 GB, OS 10.8.5, NVIDIA Quadro 4000 [view my complete system specs]
  • Wed, Jun 19 2013 11:05 PM In reply to

    Re: The old, Quicktime gamma shift question-Confused

    The problem is not with Avid MC, but with the Quicktime ProRes codec. Avid 6.5, unlike QT, can work in ProRes transparently, meaning that you can maintain luma levels and gamma through ingest, editing and export, as long as you export Same As Source. As soon as you use the QT custom options, you are using the QT ProRes encoder, which for a reason unknown to mankind insists on changing gamma.

    I have to say that I have seen people "struggling" to get things to look "correct", when in fact things on the FCP side were incorrect.

    Media Composer /w Symphony option | PT-HD | Win7Pro64 HP | OSX MBP | ISIS5000 | Nitris DX | Artist Mix & Transport & Color | AJA T-Tap | Decklink... [view my complete system specs]
  • Wed, Jun 19 2013 11:41 PM In reply to

    • othila
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    Re: The old, Quicktime gamma shift question-Confused

    Hi Job,

    Thanks for your time in replying.  Quick question with MC 6.5 If you AMA a Quicktime Prores HQ422 in 6.5 and want to trnscode defore you start editing, do you transcode to Quicktime Prores HQ422 or do you transcode to DNXHD? 

    Cheers

    Avid Media Composer 8.3.1 Matrox MX02 on MacPro4,1 Quad-Core Intel Xeon 2.66 GHz, Memory: 16 GB, OS 10.8.5, NVIDIA Quadro 4000 [view my complete system specs]
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