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Compression gives interviewee red nose! What am I doing wrong???

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Antony Christie
Compression gives interviewee red nose! What am I doing wrong???
on Mar 28, 2015 at 2:00:31 pm

I shot a well light interview with my NEX-FS100.

I used a nice vibrant picture profile (recommended by Doug Jenson of Vortex Media in his FS100 DVD).

I purposely shot it a bit dark so I could brighten it with gain in post.

I transcoded it to DNxHD 120 MXF to get it into my Avid MC 6.

I've colour corrected it and it looks great in MC.

I then export as: Quicktime movie, H.264, frame rate: current, key frames: auto, frame reordering: on, encoding: multi-pass, data rate: auto.

HOWEVER, my interviewee looks like they've a very sunburned nose!!! (And slightly more so once uploaded to Youtube).

I've tried RGB and 601/709 (601/709 gives slightly less red MOV).

I've tried altering the colour correcting exporting and uploading many times but I can't seem to keep it vibrant without the red nose!

What am I doing wrong???

Thought maybe I should try exporting QT ref and compressing using Squeeze, and some other ideas, but this all take time and that's something I don't have.

2 x Sony NEX-FS100E's
Mac Pro (early 2009) 2 x 2.66GHz Quad-Core Intel Xeon "Nehalem" processors, 12GB of 1066MHz DDR3 ECC memory, 2 x NVIDIA GeForce GT 120 with 512MB GDDR3 memory. Mac OS X Lion 10.7.4.
Avid Media Composer 6.0.1, Pro Tools 10,


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Michael Phillips
Re: Compression gives interviewee red nose! What am I doing wrong???
on Mar 28, 2015 at 3:06:16 pm

Well first off, Media Composer UI windows should not be used for color reference, especially in that version. In v8.3, you can actually apply different color spaces to the GUI and full screen playback, so assuming that monitors are calibrated to proper RGB, then you're much closer.

I would test this by by first exporting a .mov file with "same as source" and look at that outside Media Composer. Also keep in mind that MoviePlayer likes to add its own interpretation of color space, etc. How does the file look there? Typically, an H.264 compression will not change colors unless you have filters active as some apps allow you to do.

And when you're color correcting, are you using a calibrated rec 709 color monitor with proper I/O? Media Composer is a video system meaning it wants video levels and color space for most everything it does. You can cheat a bit with this and work in full range, but you have to be aware of all your steps when doing so.

And I have to say, that shooting underexposed seems a little weird to me. Perhaps that depends on camera and codec type being recorded to. But underexposing shots can bring out more noise than necessary.

Also, when you look at your image with the waveform/vectorscope, is there red in the shadows and such that you are not seeing on the GUI?


Michael


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Antony Christie
Re: Compression gives interviewee red nose! What am I doing wrong???
on Apr 19, 2015 at 2:17:50 pm

Hi Michael

Thanks for your help, was too busy to reply before, but your comments were appreciated!

I found that exporting as qt ref and then using Squeeze to encode the video instead of exporting straight from MC did the job.

The main reason for under-exposing whilst shooting (only a little mind you) is because I use a Dedolight DP1 Gobo Projection kit for background and use it on full brightness, under-exposing then bringing it up in post really helps make the background really pop.

Probably not ideal but works for me!

Again, many thanks
Antony

2 x Sony NEX-FS100E's
Mac Pro (early 2009) 2 x 2.66GHz Quad-Core Intel Xeon "Nehalem" processors, 12GB of 1066MHz DDR3 ECC memory, 2 x NVIDIA GeForce GT 120 with 512MB GDDR3 memory. Mac OS X Lion 10.7.4.
Avid Media Composer 6.0.1, Pro Tools 10,


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Pat Horridge
Re: Compression gives interviewee red nose! What am I doing wrong???
on Mar 29, 2015 at 9:20:19 am

I'd agree with Michael. Shooting under exposed isn't helpful.
Your Y B-Y R-Y data has low quantising levels and lifting the gain just stretches the steps.
You do better shooting well exposed and add grain if you want the film mullered look.

Pat Horridge
Technical Director, Trainer, Avid Certified Instructor
Free online Tutorials at VET digital media academy online http://vimeo.com/channels/752951
VET
Production Editing Digital Media Design DVD
T +44 (0)20 7505 4701 | F +44 (0)20 7505 4800 | E pat@vet.co.uk |
http://www.vet.co.uk | Lux Building 2-4 Hoxton Square London N1 6US


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Antony Christie
Re: Compression gives interviewee red nose! What am I doing wrong???
on Apr 19, 2015 at 2:21:19 pm

Hi Pat

I trust you're well? How's the rest of the team over at VET?

Thanks for your help, was too busy to reply before, but your comments were appreciated!

As I've just explained to Michael, I found that exporting as qt ref and then using Squeeze to encode the video instead of exporting straight from MC did the job.

The main reason for under-exposing whilst shooting (only a little mind you) is because I use a Dedolight DP1 Gobo Projection kit for background and use it on full brightness, under-exposing then bringing it up in post really helps make the background really pop.

Probably not ideal but works for me!

I did however heed your advice and took my exposure up a little.

Again, many thanks
Antony

2 x Sony NEX-FS100E's
Mac Pro (early 2009) 2 x 2.66GHz Quad-Core Intel Xeon "Nehalem" processors, 12GB of 1066MHz DDR3 ECC memory, 2 x NVIDIA GeForce GT 120 with 512MB GDDR3 memory. Mac OS X Lion 10.7.4.
Avid Media Composer 6.0.1, Pro Tools 10,


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Michael Phillips
Re: Compression gives interviewee red nose! What am I doing wrong???
on Apr 19, 2015 at 6:35:55 pm

I would never recommend exporting H.264 or other compressed file types directly from Media Composer as that just uses QuickTime to do the compression and it has never been good. Always use a third party tool that gives you some control over the compression. SO either uses export "same as source" or QT Reference which points to the timeline's original essence to be encoded by a third party application.


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