P3_DCI-Color_Workflow

Hi All,

I am grading a film shot on an Alexa at 2K ProRes 4444 in Log C and I need to deliver a DCP and would like to attempt to give it justice by grading in P3 DCI. Here is how I set up the Color Management tab in the Project Settings.

DR_Settings.png (31.51 KiB) Viewed 5729 times

I am grading on a consumer grade ''P3'' calibrated monitor. I am aware that my monitor does not accurately display P3 at even 90% but please do help me out with the following.
After setting up my project all looked absolutely fine but then I noticed that if you right click on one of your rushes in the dropdown menu there is a separate ''input color space'' bar and when you hover over it, this happens

Rec709.png (626.12 KiB) Viewed 5729 times

As you can see this clearly says that I am in Rec709 Gamma2.4 colorspace which is completely different to my project settings altogether and not what I want. I then saw that there is an option on the top to bring my 'input color space' back to my project settings one which is ''ARRI Log C'' and this happened

LogC.png (723.5 KiB) Viewed 5729 times

I am no color scientist but this does not look like Log C to me. I am a bit confused as to what I am suppose to be seeing. I have a pretty straightforward concept. I need to view, grade and deliver in P3 DCI and now I am totally lost as to what color space I am in and what I am delivering

First, if your monitor does not cover P3, you're better off grading in a colorspace that it covers, like Rec709.

When you do the output, Resolve will convert to p3 or the desired colorspace and it will be fine. This is what most people do, even people with monitors that cover 97% percent of the P3 range.

When you select input colorspace, it will convert all your footage to the timeline colorspace. That's why it looks different.

If you don't want that automatic conversion, choose bypass instead of Arri Log. After you bypass, you can still do select Arri log on a clip by clip basis by rightclking the thumbnails on the color page or in the media pool... I'd rather do it that way with the conversion with a color transform OFX node, so I have more control over the image.

If you wanted to make sure you're on a P3 space, you can leave your timeline at P3 and set your output to a color space your monitor can handle... But not worth the trouble. The more straightforward and simple your approach is, the less likely for you to make a mistake while grading or doing a delivery.

Here are 3 options for 3 different projects I've worked on.

The 3rd option I started on a P3 environment and had to continue on Rec709 later on. It was very cumbersome workflow, mainly because it had a lot of VFX to be done, so this mismatch needed to be accounted for each time footage went out and back in... I would not recommend this approach.

I suggest using the ACES workflow. It will simplify a lot of things for you.

I suggest using the ACES workflow. It will simplify a lot of things for you.

That's been my experience.

Whatever workflow you choose, you will be grading in the color space of your display, as that's where you're making your grading decisions. Even if using ACES and a P3 timeline, you will be seeing only REC709 and grading for that. So really not much difference, color management wise, as working in a non-color managed project in REC 709 and converting to p3 after the grade is done.

If your display can only show 90% of P3, and you've calibrated the display for P3, everything will look correct until you get near the boundaries of the P3 color space, and then your display will clip these colors at the maximum saturation that your display can show. I'm not sure this method is crazy, if you can show enough P3 colors that it makes this approach worthwhile... and you're not often at the maximum saturation of colors that your display can reproduce.

So, it's time for some testing here. Grade and render a test movie (with some good saturated colors) in P3 (your display's 90% P3), render it. Then, open this rendered movie in a REC709 project with your display set to REC709 and convert your movie to REC709 and see if it looks correct (non color managed project). If it does, your P3 movie should still look pretty good on a true P3 display (with perhaps some more color detail in the most saturated colors).

A true proper test would be to grade in your P3 90% display and then create a DCP in DCIP3 and view it in a calibrated theater to see if all looks correct.

I graded a film I shot last year in Arri LogC, in REC709 and converted to P3 DCI for the DCP. And... this movie had a lot of saturated color and I was disappointed in the DCP as I could see that I could have saturated even more, but I was limited to the clipping in REC709 when I graded. So, I set my grading display to P3 (maybe 93% P3) and looked at how much further I could have gone if I had graded in P3, and was quite amazed at how limited REC709 can be. And I'm now considering that grading, even in 93% of P3 would have some benefits. I wouldn't be able see the maximum saturation of every color, but I would have increased the volume of color I was working with to a significant degree. I suspect if I had used this approach, then the DCP would err only in that it looked slightly better than my display.

not that approach i would take.... no... 90% of P3 is not P3 in any way shape or form - with the 90% of P3 mon, the missing 10% is in the shadows where saturation is critical

also P3 asks for a .05nit viewing enviroment, a single ui mon's glare is enough to make that impossiable, hence most gradeing theatres haveing the ui and scope's screens beside the colorist so one can lean forward past them, or turn them off and use the surface

often there's no reason to use the extanded gamut of P3 anyway (unless it's Bollywood or horror), most films i grade never come close to the limits of 709 much less P3

i do prefer ACEScct - match ODT to monitor, make sure mon is callibrated accuratly

i would suggest gradeing in 709 with mon that has completly rock solid callibartion, and either
a trim pass in a proper gradeing theatre
-or-
test screen in a local cinema + make notes and address

often there's no reason to use the extended gamut of P3 anyway (unless it's Bollywood or horror), most films i grade never come close to the limits of 709 much less P3

I used to think the same, until till I made the comparison test. I was really surprised by how much further I could go in P3 vs Rec709. What appears "over saturated" in REC709, can look quite pleasing in P3 for the appropriate project.

The compromise of grading on a display vs. DCI projector will always be there. Whether grading REC709 or P3.

Since that is a "given", then I don't see any reason why one should not grade in P3 on a display, vs REC709 on a display, if a projection theater is beyond the resources of the project. The bigger issue, as would be the same as grading P3 in a theater, is that a trim pass may be useful for any REC709 deliverable.

What appears "over saturated" in REC709, can look quite pleasing in P3

That's also been my experience.

What appears "over saturated" in REC709, can look quite pleasing in P3

That's also been my experience.

Haven't had that experience. Will try on my next film.

Did you both do that comparison on the same monitor or on a screen? The reason I ask is just to know if this could have been a difference introduced by the projection setup and not because of the colorspace itself. Some projected images might look less contrasty and desaturated than in a monitor.

In terms of the 10% percent difference on the monitor, it will depend on where that 10% is. That's what Steve Shaw once told me similar scenario.

one small thing from the front lines (and yes i do use P3 when it's approprate and accurate)

tail light on a red sign are a non issue in 709, brightiest thing in frame P3
so you have a shot where a car pulls just past a stop sign and the hero rolls out of the pasenager door
guess what you see in P3? a stop sign, a bright stop sign, a really bright stop sign, but no hero

so yea what did you gain by working P3? adding masks and keys to control the gamut that add's nothing to the film or story

there's shows where it makes sense, pick your battles wisely.. that show made sense to work in P3 for two scenes, so the entire show was graded in P3

if i had used a mon with 90% of P3 i'd have a long sad face after viewing the DCP in a theatre, but i used a Dolby 4200, then did a confidence pass in a day with a Christe

but a mon with only 90% of P3 shuts down the conversation at the start... it's not in the ballpark of reliable from the get go

Did you both do that comparison on the same monitor or on a screen?

Filmed on the GH5 in V-Log, viewed on a calibrated 4K Home Theater projector.

P3 definitely gave a more pleasing result than 709. (As did 2020.)

Yep. 90% is not near big enough to use as any point of reference (specially when you put your grade to the gamut edges). If it would be 98% then we could debate depending on project rank.

Thank you all for the responses. I knew this topic would arouse a lot of discussion and different opinions which is great.

However I only one person actually attempted to answer my question. Which was: How do I set up my project correctly so I see and export a P3 DCP of my film.

I am still lost as to what color input I should set so that davinci recognises that I shot in ARRI Log C and see ARRI Log C when I start grading.

Should I set everything in the project settings and how? Or should I set the input transform per clip by right clicking on each thumbnail?

I am doing my finishing touches on a P3 Projector so all the talk about what monitor I am using is out of the topic of the conversation

Thank you in advance

what color input I should set so that davinci recognises that I shot in ARRI Log C

There is an Alexa IDT in ACES mode. I prefer the global setting.

Jim's got it

ACEScct / Alexa IDT / 709 ODT and set 709 on your mon
when you go for the trim pass on a proj, set the ODT to P3

safe and reliable

I am still lost as to what color input I should set so that davinci recognises that I shot in ARRI Log C and see ARRI Log C when I start grading.

Should I set everything in the project settings and how? Or should I set the input transform per clip by right clicking on each thumbnail?


Thank you in advance

You always set it to much your recording nature. If you use source from many cameras then you set matching IDT for each source on clip level. It's quite simple. Same with ODT- you set as your delivery/monitoring needs.

Thank you all for the responses. I knew this topic would arouse a lot of discussion and different opinions which is great.

However I only one person actually attempted to answer my question. Which was: How do I set up my project correctly so I see and export a P3 DCP of my film.

I am still lost as to what color input I should set so that davinci recognises that I shot in ARRI Log C and see ARRI Log C when I start grading.

Should I set everything in the project settings and how? Or should I set the input transform per clip by right clicking on each thumbnail?

I am doing my finishing touches on a P3 Projector so all the talk about what monitor I am using is out of the topic of the conversation

Thank you in advance

I tried to answer those questions for you.

It all depends on what you're trying to achieve. That was why I probably gave you a general answer. Everyone has their own recipe that they like and once you understand how all the pieces fit together, you'll find yours.

That's why some recommend ACES, others RCM or no color management at all.

In your case. If you have your project set up for P3, Resolve will automatically do the proper XYZ conversion for the DCP.

If you trust your monitor to be accurate enough to work on P3, then there are 3 ways you can set up your project. No RCM making your timeline P3-DCI, RCM making your timeline and output P3-DCI or ACES.

I think you mean the opposite when you say you want resolve to recognize your Arri log. From your previous post, I think you mean you want to be able to view it as log, which kind of mean that you don't want resolve to "recognize" instead to show as is.

I make this distinction because depending on your settings, if you let Resolve know what type of footage it is, it will attempt to convert it to your working environment. In your case it will apply a P3 transform, which would be the equivalent of putting a conversion LUT to limit the range to P3.

That's why in my previous post I recommended to use "bypass" (so resolve is not aware and doesn't convert), that way you see the log footage and are able to work with the full dynamic range of log.

Depending of your color management settings, you can later on choose input color space on a clip by clip basis.

So in short, color input: bypass.

I think it is important that you try to understand how these steps affect each other, because if you just follow someone elses recipe blindly, you might end up painting yourself into a corner.

That's why in my previous post I recommended to use "bypass" (so resolve is not aware and doesn't convert), that way you see the log footage and are able to work with the full dynamic range of log.

Depending of your color management settings, you can later on choose input color space on a clip by clip basis.

So in short, color input: bypass.

Yes, but then you grade from LOG etc. and not everyone is skilled enough to do so.
Also- when you apply IDT you don't loose any details. You still should be able to recover all possible data, same as with no IDT case.