Grading for P3 Color Space… on a budget

[Chris Dk]

I see some of you say there is no visible difference between P3 and Rec.709, which I disagree. I have involved a horror movie recently, grading in P3.

After it finished, I jump the cable to our Rec.709 Monitor, you will see dramatically difference. The green and cyan part turns to be totally blue, and there is huge contrast and brightness difference.

So, for those say no visible difference, are you sure you digital projector was set to P3, not Rec.709.

[Chris Dk]

Usually, Rec.709 includes specifications: Rec.709 Color Gamut, White is D65, Gamma is 2.35-2.4; Video Range is SMPTE.

P3 includes: P3Color Gamut, White point is D-cinema; Gamma is 2.6; Video Range is full range

However, if you only set Gamut to Rec.709, others all same with P3, you will see litte change, more saturated fresh tone, more saturated.

If you change all options to Rec.709, you will find extremely different.

I heard that for some projectors, like Barco DP2000, the Gamut is bound to white point, if you use Rec.709 Gamut for grading, the white point will set to D65 automatically.

[Sumesh Lekhi]

P3 graded film on rec 709= the output looks more blue/purplish,it gets highly contrasted, with the whites appearing more exposed and shadows crushed, losing details to black. Overall brightness increases.

[Margus Voll]

Calibration is the key here on monitor and later in cinema.

If any of them is off the you get variable results.

—

Margus

https://iconstudios.eu

Resolve 11
BMC 2,5k

[Marc Wielage]

Wow, here’s a 4-year-old thread back from the dead.

My observation is where you get in trouble with Rec709 -> P3 conversion is at the extremes: very bright scenes, or extremely colorful (and/or clipped) scenes. I’ve seen issues with both on occasion, but we’re talking less than a minute out of an entire feature.

I always suggest to clients that they QC the entire feature in a DCI-compliant screening room prior to release (even at a festival), just to make sure there are no surprises. If there’s just a few momentary shots that are problematic, we can always take them down or pull back on the correction to reduce any issues. But in a perfect world, you’d always try to actually do the entire color correction in a DCI theater.