709 Gamma 2.4

Anything and everything to do with DCP-o-matic.
Burtinstien
Posts: 2
Joined: Wed Jan 03, 2018 10:21 pm

709 Gamma 2.4

Post by Burtinstien »

Hi I'm a little new to this - creating a DCP. I have a very simple question and i was wondering if anyone could help me. I have a film i want to convert and it's graded in rec709 but the gamma was 2,4.
In the program the preset gamma for rec709 is 2,2 - do i need to use the custom settings to set the gamma to 2,4 to get a true result?
Any advice appreciated - thanks.
Carsten
Posts: 2806
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: 709 Gamma 2.4

Post by Carsten »

Hi,

You may create a custom color conversion, using 2.4, or, use the BT.1886 preset, which, in current DOM versions, means the same.

You may also look at this post from the mailing list:

http://main.carlh.net/pipermail/dcpomat ... 01933.html

I am not an expert on color conversion or colorspace issues, but I may be correct here.
Essentially, and that irritates many (including me), the original rec.709 definition did never include a gamma choice. They added that later on due to advancements in display technology, but it appears that most of todays gear claiming to use rec.709 is actually based on BT.1886. They just seem to prefer the term rec.709 because it appears more common, and because current revisions of rec.709 and BT.1886 comply.


- Carsten
Burtinstien
Posts: 2
Joined: Wed Jan 03, 2018 10:21 pm

Re: 709 Gamma 2.4

Post by Burtinstien »

Thank you very much for taking the time to reply very much appreciated.