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Avid Color Settings

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Joshua Menco
Avid Color Settings
on Sep 5, 2013 at 3:44:49 pm

Can somebody explain to me how to set up Avid projects to handle colour correctly. I'm reading lot's of things on the internet but It all gets way to technical for me :(

I usually film on DSLR btw.

My question is threefold:
-What settings to use in the format box when setting up a new project? (RGB709 of YcBcR709)
-What settings to use for File Pixel to Video Mapping on import (RGB 0-255, Computer RGB or 601SD or 709HD 16-235)
-Export YcBcR or RGB?

How should I export for web and how should I export for TV?

Cheers!


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Michael Phillips
Re: Avid Color Settings
on Sep 5, 2013 at 4:54:17 pm

Take a read through Job's excellent whitepaper on the subject of levels and Import/Export choices:
http://www.jobterburg.nl/Publications/601_709_RGB.pdf

You can also look to AMA linking which gives you an addition choice when going to source settings.

What version of software?
What is your primary deliverable? web or broadcast television?


Michael


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Joshua Menco
Re: Avid Color Settings
on Sep 5, 2013 at 10:06:06 pm

Thanks again for the reply Michael :)
Excellent article from my fellow countryman!

I'm using MC7.

Most of my work is shot on canon DSLR and is used on the web.

However I'll be editing some stuff for broadcast soon.

Cheers!


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Joshua Menco
Re: Avid Color Settings
on Sep 5, 2013 at 10:46:48 pm

I'm guessing this is what you were mentioning https://dl.dropboxusercontent.com/u/1146151/Screen%20Shot%202013-09-06%20at...
what would be a reason to set this to graphic levels while working with AMA?
And does this affect things when you transcode to DNXHD?


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Michael Phillips
Re: Avid Color Settings
on Sep 5, 2013 at 11:36:34 pm

Well this is where things get interesting. As far as source settings I would leave it as "do nothing". What you see is what you get and deal with it in color correction. Setting it to "graphic levels" will expand the levels most likely clipping blacks and whites that were between 0-15 and 236-255. If you knew you were going to prepare for broadcast, and you had full range levels, then you would select "video levels" ensuring that whatever black levels between 0-15 become 16+ and same for 236-255 become 235-.

There is a school of thought that since everything inside Media Composer is assumed to be video levels, and that is stuff like Avid black in timeline, title tool, paint, etc. will all be 16-235 range. So many people will work as though it were for broadcast, then when delivering to the web, will export out as RGB levels expanding 16-235 to 0-255.


Michael


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Joshua Menco
Re: Avid Color Settings
on Sep 6, 2013 at 11:13:56 am

Ok I'm starting to understand this stuff now!

So take a look at this image:

https://dl.dropboxusercontent.com/u/1146151/Screen%20Shot%202013-09-06%20at...

This is 5DMkII footage (16-235 if i'm not mistaken). I imported it at 601-709 since it does not need to be remapped.

This is correct, right? And the clipping I'm seeing at 235 and 16 is occurring because the 5DMkII simply can't go beyond those values..?
Or did I do something wrong here and am I supposed to see illegal values on the Y-waveform?


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Michael Phillips
Re: Avid Color Settings
on Sep 6, 2013 at 3:05:40 pm

Importing it at 601/709 should just bring it in with nothing changing in the file itself. It is interesting that there is clipping at 16 and 235 which may have been done in camera. What value do you get if you shoot a few seconds with the lens cap on? 0, 16, other?

Michael


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Joshua Menco
Re: Avid Color Settings
on Sep 6, 2013 at 4:32:23 pm

This is film with the lens cap on. Not from the 5d though but from my 60D (the 5d was a rental). However, this shouldn't make a difference.


https://dl.dropboxusercontent.com/u/1146151/Screen%20Shot%202013-09-06%20at...

Is is strange that black is not at 16?


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Michael Phillips
Re: Avid Color Settings
on Sep 6, 2013 at 7:10:22 pm

At this point, I would look to whatever settings are in the camera for contrast, etc. and whether this is using a CineStye LUT can that can squeeze more dynamic range by lifting blacks, etc. This is not a bad thing, you can correct in color correction by clicking the auto-black - or via AMA, go to source settings and set "expand range" to see where that black level ends up.

I did a full test on the DVX100 when it came out years ago on the relationship between pedestal setting and where that ended up on the IRE/RGB scale so that users would know where to best set it for their needs. I guess a similar thing could be done for the DSLR world and its settings that affect overall image.

http://24p.com/dvx.htm



Michael


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Joshua Menco
Re: Avid Color Settings
on Sep 7, 2013 at 4:40:52 pm

You're right:) I'm using Cinestyle.

So i'm presuming cinestyle increases your dynamic range by raising black to a value somewhere above 16 and white somewhere below 235 so that stuff that would normally be clipped is now registered as a legal value (i.e. between 16 and 235 instead of 0-16 and 235-255)..? That is why you need to apply a LUT or colour correct cinestyle footage; so that black is once again made black.

Am i right ?


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Michael Phillips
Re: Avid Color Settings
on Sep 7, 2013 at 6:14:18 pm

Exactly - rather than have some of the details in the shadows highlights be lost at time of capture, the CineStyle LUT (or any of these camera LUTS that are tuned to their sensors) retain as much as they can. Depending on the LUT you apply in Post, you can have it go to Rec.709, or something else. Applying a CineStyle->Rec.709 LUT for example will make it 16-235 - this may be fine for quick correction and for editing in dailies, but most of the time, the LUT is removed during the color correction phase to allow the colorist to selectively preserve detail in shadow and highlights as they see fit rather than a one size fits all. It's about control of the image. Sort of like the difference between using the default settings of a Effect template and going in and making it unique.

Most workflows will apply the LUT for dailies, then remove it for color correction.

6483_5dcinestyledavinciresolve33.cube.zip

The link should download a LUT I created for CineStyle in Resolve but can also be used in MC V7.


Michael


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Joshua Menco
Re: Avid Color Settings
on Sep 12, 2013 at 9:27:27 pm

Michael,

I need your expertise once more:)

I've started working for a television production company. Saturday is my first day there.
I'm going to be receiving clips from several people (mostly laymen) and will have to import them in Avid and edit with them.

In other words, some clips may be 0-255, some 16-235 but I won't know which are what.
What is a good workflow in your opinion to keep the colors correct for all the clips? I'd rather not import the clips and then go over them one by one to see if all the colors have come through correctly.


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Michael Phillips
Re: Avid Color Settings
on Sep 12, 2013 at 11:09:54 pm

For each card or drive of media that comes in, I would recommend AMA linking to it. Then select one of the clips and go to source settings and go to one a frame where there is black or very dark. Look at the histogram - is it at 0 or 16? (or higher?). Form the source setting s you can apply the proper image color space.
Also, AMA transcode at least twice as fast as an import.

If you just want to deal with it all in color correction later, import/AMA link at Rec.709 or full range for everything.

Michael


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