Thanks for the info Erik. They shot on the Sony F65.

Those values listed in your example are the default CDL values - no look. If that is all the CDL info that is present in the Avid BIN, then the CDL data was not implemented in the dailies process correctly.

I'd believe that. They are getting very close to the finger pointing phase of the conversation. :)

David Torno

Visual Effects Artist & Supervisor

http://www.ghosttownmedia.com

O: 213.739.2290

C: 818.391.6060

---------------------

http://www.sydefxink.com

http://aeioweyou.blogspot.com

http://mactex.blogspot.com

"The most useless day is that in which we do not laugh"

-Charles Field

On Aug 1, 2013, at 11:45 AM, Erik Hansen <eahansen@gmail.com> wrote:

This is the standard and the way that is supposed to work. What may be happening is that there may also be a LUT involved, especially if shooting on an Alexa - the ARRI LogC-to-Rec709 transform.

Normally, you should be applying the LUT and CDL information for review materials only, finished shots should not have either baked-in.

The ARRI Look system, is actually based on this - LogC-to-Rec709 transform, followed by CDL values (possibly Printer Lights too).

Those values listed in your example are the default CDL values - no look. If that is all the CDL info that is present in the Avid BIN, then the CDL data was not implemented in the dailies process correctly.

If the DP created CDL values, I would contact them. If perhaps they created ARRI Look files, you can load them into ARRI's LUT creator and export LUTs if you like. OCIO can also take CDL values and burn generic LUTs.

A .CDL file is just an XML document of the values in your example.

Erik

On Wed, Jul 31, 2013 at 10:21 PM, David Torno <torno@sydefxink.com> wrote:

Thanks very much Bob for that thorough explanation. I love detailed oriented people. They seem to be rare in this industry. :)

> Or use Color Finesse within AE which can read ASC CDLs directly, so you'd just need to invert the values in the .cdl file, then load it in.

If they can get me actual .cdl files that would be great, but I'm not holding my breath. Right now, the editor is exporting the CDL data as part of his EDL and nothing more. The dailies had CDL metadata applied by a guy who is no longer on the production and the producers opted to not pay $2500 for actual LUT files. Starting to question my career choices. :)

> With all that said, is the CDL really your "viewing LUT" or is it representation of the color correction that's been done, which is the normal use for a CDL?

So far from what little info I have managed to procure from the production, the DP designed 4-6 CDL's I think. Day and night exterior, day and night interior. I may be wrong on that though. What I think is happening (total guess on this) is that the CDL's were applied to the dailies, which went to edit. Color got raw footage and had the LUT data but won't export without payment. So we in VFX land are getting 10bit DPX in raw color without the CDL info and edit has no clue as to why it's all not WYSIWYG, but I can't say really.


David Torno
Visual Effects Artist & Supervisor
http://www.ghosttownmedia.com
O: 213.739.2290
C: 818.391.6060
---------------------
http://www.sydefxink.com
http://aeioweyou.blogspot.com
http://mactex.blogspot.com

"The most useless day is that in which we do not laugh"
-Charles Field

On Jul 31, 2013, at 7:44 PM, "Bob Currier" <rcurrier@synthetic-ap.com> wrote:

> "SOP" is "Slope, Offset, Power" in ASC CDL speak. We chose different names because many people calculate lift/gamma/gain in different ways.
>
> Slope is gain (multiplication). Offset is lift (addition). Power is gamma (y^(1/x)). Saturation is saturation.
>
> To reverse it, enter the reciprocal of slope as your "gain." Enter the reciprocal of power as "gamma." And enter the negative of offset as "lift." Enter saturation as the reciprocal of the CDL value.
>
> The gain setting should work regardless of the color correction app. The gamma value, however, may need to be entered as a reciprocal. The lift value is the hardest to deal with. Many apps adjust gain along with the lift setting, while the ASC CDL is a pure offset.
>
> Or use Color Finesse within AE which can read ASC CDLs directly, so you'd just need to invert the values in the .cdl file, then load it in.
>
> With all that said, is the CDL really your "viewing LUT" or is it representation of the color correction that's been done, which is the normal use for a CDL?
>
> -----
> Bob Currier                                  rcurrier@synthetic-ap.com
> Synthetic Aperture                           www.synthetic-ap.com
> Helping Make Your Work Look Its Best
>
> On Thu, Aug 1, 2013 6:41 PM, David Torno <torno@sydefxink.com> wrote:
>
>> Curious question to anyone who has done a lot of CDL (Color Descision
>> List) work. I'm use to using a generic Cineon Log to Lin for viewing and
>> then doing a reverse process with Cineon Lin to Log for final output.
>> Not once have I ever gotten a proper LUT on a project in the 13+ years
>> I've been doing this work. Sad, very sad. Anyways, someone finally has
>> some CDL values (not an actual LUT file mind you) and I can easily,
>> manually, input the values into Colorista - Free, but how would I do a
>> reverse of this properly? I'm assuming this CDL is essentially my
>> "viewing" LUT and I would need it's opposite to reverse it all back with
>> VFX applied. Did that make sense? Thanks for any insight.
>>
>> What the editor exported for me, is an EDL that contained these lines as
>> well as other clip data.
>>
>> *ASC_SOP (1.0000 1.0000 1.0000)(0.0000 0.0000 0.0000)(1.0000 1.0000 1.0000)
>> *ASC_SAT 1
>>
>>
>> The ASC_SOP and ASC_SAT data exists, even though they are default
>> neutral values. I'm hopeful that he will be able to get the actual CDL
>> values that he is seeing in AVID.
>>
>>
>> --
>> David Torno
>> Visual Effects Artist and Supervisor
>> http://www.ghosttownmedia.com
>> david@ghosttownmedia.com
>> O: 213.739.2290
>> C: 818.391.6060
>> ------------------------------------------------
>> http://www.sydefxink.com  (main portfolio)
>> http://aeioweyou.blogspot.com (vfx tutorials and AE scripts blog)
>> http://mactex.blogspot.com  (free textures blog)
>>
>>
>>
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