PhilmColor Output LUT with Rec709A

[Ryan Chernin]

If I’m using PhilmColor output luts, like ARC or ASP, but working with one of those new Apple MBP displays, should I set my timeline CS to RWG/Log3G10 and output CS to rec709 gamma 2.4 or rec709A?

I have the “use Mac display color profiles” box checked under general preferences.

or perhaps should I be setting my output CS to Rec709A but adding an output transform (from 2.4 to A) after the PhilmColor lut?

thanks for your your patience, I’m still learning as I go along

 

[Phil Holland]

Timeline = RWG/Log3G10
Output = R709/Gamma 2.4

Whoop there it is.

 

[Ryan Chernin]

Timeline = RWG/Log3G10
Output = R709/Gamma 2.4

Whoop there it is.

Thanks Phil. And leave the “Mac display profiles” box checked? On export, should the tag remain gamma 2.4?

 

[Phil Holland]

Thanks Phil. And leave the “Mac display profiles” box checked? On export, should the tag remain gamma 2.4?

Generally I don't do anything specific for Mac display or catering to quicktime-isms, but you'll want to check if you have gamma discrepancies on export.

 

[Patrick Tresch]

what is REC709 A?

 

[Ryan Chernin]

Generally I don't do anything specific for Mac display or catering to quicktime-isms, but you'll want to check if you have gamma discrepancies on export.

Gotcha. There was definitely a discrepancy, but I was able to sort it by adjusting the MBP display settings and redoing my grade with the display limited to their “rec709 bt1886” color profile / brightness level.

I love using your philmcolor3 luts. MSO Cine is my jam.

 

[Ryan Chernin]

what is REC709 A?

Basically it’s some new Mac display profile thing that’s supposed to make everything look consistent across Apple devices, but if you’re grading on a new Mac “XDR” display, and set your output cs to the usual rec709 gamma 2.4, everything will look washed out like the gamma’s been raised or something.

Some more experienced folks on the forum, or at these links below, will probably be able to explain it better than myself.

https://www.liftgammagain.com/forum/index.php?threads/davincis-new-rec-709-a.14661/

https://www.reddit.com/r/colorists/...urce=share&utm_medium=ios_app&utm_name=iossmf

https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=114047

 

[Phil Holland]

Gotcha. There was definitely a discrepancy, but I was able to sort it by adjusting the MBP display settings and redoing my grade with the display limited to their “rec709 bt1886” color profile / brightness level.

I love using your philmcolor3 luts. MSO Cine is my jam.

Good to hear Ryan.

MSO Cine is the same exact curve as RED's Medium/Soft and BT.1886 curve with about 80% their color science and about 20% my own with high gamut compression. I use it very, very often.

For the curious, in the SDK presets Medium/Soft is also what RED defaults to for BT.1886 as well.

All manufacturers and services at the moment are very focused on Gamma 2.4 being the "standard". Been that way for a while. BT.1886 is very damn close and works well in this world and at this point they are virtually interchangeable, though not technically the same thing.