Film-Tech Forum ARCHIVE: P3 grade out to DCP

This is topic P3 grade out to DCP in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Rayjohn Tagayon (Member # 9659) on 03-23-2017, 10:33 PM:

Hi all, by next week we'll have our supplier set our projector ready for P3 grading. Our previous grading projects were all done in Rec 709. And the output to DCP was pretty straightforward since no color conversions had to be made.

My question is, now that our next projects will be graded in P3. HOW WILL i go about exporting the timeline as dcp? We use davinci resolve for grading and easyDCP plugin for the dcp creation. Do we just tell the mall cinemas that our dcp was graded and P3 and they should set their projector to P3 so we get the same results? Thanks in advance.

Posted by Carsten Kurz (Member # 5396) on 03-24-2017, 07:07 PM:

If cinemas had to adjust their gear the habits of every grading/mastering studio, that would be fun times.

DCP is XYZ - always, no matter what your suite is set to.

- Carsten

Posted by Rayjohn Tagayon (Member # 9659) on 03-28-2017, 12:34 AM:

So by the time the P3 grade is finished it will always be converted to XYZ when exported for dcp? What are the advantages of color grading in p3? Sorry for the noob questions. If you have suggested readings on the matter i'd happily read all of them.

Posted by Carsten Kurz (Member # 5396) on 03-28-2017, 04:02 AM:

If you grade in P3 vs. rec.709, you have a greater colorspace and gamut for grading. But the result will always be converted to XYZ (e.g. with Resolves integrated easyDCP output module). If you not only grade in P3, but also have a P3 capable monitor/display chain, you will also be able to monitor the image closer to the display environment that you have in the cinema.

Simply put, rec.709 is a consumer colorspace, P3 is a professional colorspace.
I hope you have knowledgeable people to set this all up properly, as it is not trivial to get it all right.

- Carsten

Posted by Rayjohn Tagayon (Member # 9659) on 03-30-2017, 02:10 AM:

Thank you Carsten, I've read a bit about colorspace and they all say the same thing, that P3 has an even wider color gamut than 709.

Yes, the people who will set up and do the P3 calibration on our projectors are knowledgeable. It's just that I went into the industry as a tech with little knowledge about the color spaces used for cinema. And these forums are the only places I can ask people to help me out with what I don't know.

Anyway, I have another question. Does the P3 graded video clips also convert properly when I export them as ProRes? Or do I have to apply a LUT in davinci resolve (where we do our grading) before doing a render.

Posted by Carsten Kurz (Member # 5396) on 03-30-2017, 05:17 AM:

You mean to export to ProRes instead of creating the DCP within Resolve with EasyDCP?

Every Export means you have to make a choice for a proper export colorspace as well.
Most ProRes types are rec.709, ProRes4444/XQ will also support up to 12Bit RGB(A).

What you choose depends on your intended use for this ProRes file. Just as you have to use XYZ for a DCP.

http://images.apple.com/final-cut-pro/docs/Apple_ProRes_White_Paper.pdf

- Carsten

Posted by Rayjohn Tagayon (Member # 9659) on 03-30-2017, 09:48 AM:

Yes, like for example the movie has already been screened for a month in DCP and the producers would like to have a Prores 4444 copy. For past projects I just use the default prores 4444 preset built-in to resolve to export. I wonder If I would have to do anything extra for a project graded in p3 before rendering it out

Posted by Carsten Kurz (Member # 5396) on 03-31-2017, 04:37 AM:

Depends on what they want to do with this copy. A standard color conversion is usually sufficient, but if it is critical material, e.g. in highlights and shadows, a LUT conversion may help. Prores 4444 is not meant to be a presentation format, so it would usually be utilized for another conversion, e.g. for a rec709 conversion for DVD, Bluray, or internet.

- Carsten

Posted by Rayjohn Tagayon (Member # 9659) on 03-31-2017, 09:25 PM:

Okay got it.

Thanks Carsten! You helped me out a lot [Smile]