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Resolve and Monitor Color Correction

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Andrea Franchini
Resolve and Monitor Color Correction
on May 9, 2018 at 9:23:51 am

Hello,

Im a new member, even though I've been a long time visitor of this amazing forum so I really hope you can help me.
This is not strictly related to davinci, but I couldn't find a better place.

Im a beginner in the movie field and before I start to shot my first video I want to understand whether I have all the requirements to at least guarantee my displays met some sort of industry standard when it comes to color accuracy. Of course I understand that with a limited budget nothing will be perfect, but I would like to get as near as possible.
So after many long researches I still have some doubts regarding color correction and workflow when it comes to video post-production.
Since my target will be mostly home theater and hopefully the cinema in my town I understood that the color standards involved are REC 709 and DCI P3. By logic, to meet these requirements, I need to calibrate my monitor (which is only capable of 100% SRGB) to the REC 709 standard. Hence I would need a colorimeter (like x-rite or spyder) to calibrate my display.
But every time I read about color correction most people do not try to target a specific standard but instead they correct the display to be as neutral as possible, which also make sense, but at this point we guarantee neutral colors but not consistency when we will deliver the video to a home cinema (like on a bluray) or a cinema projector. So what should I do? Do you target specific standard? Do you neutralize any color shift and that's it, else?

There's also another point, this time regarding the post-production workflow.
Let's say I have a "neutral" display (calibrated by dialing the settings in its menu) and an ICC profile to fix the remaining errors. As far as I know on windows ICC profile are somehow tricky since some application will simply ignore them hence making the profile completely useless, while other program can use them to display color accurate images.
So I import my video on Resolve (my version is 14) do I have to take extra steps to use my display ICC profile to see a correct image, or it will automatically use it? If I do a profile specific to Resolve (some calibration software allows it) , will it be added to the underlaying windows ICC hence rendering the colors wrong?

Now to make everything even more complicated let's say I have an external projector, and I do, then to have a more faithful representation of how the actual footage will look on a home cinema environment I'm definitely supposed to color correct the projector too. BUT do I color correct it to be neutral? Or to meet the rec 709 standard?

I understand those are a lot of questions and most likely there's a ton of informations Im missing, but Im more than willing to learn and to be directed to the right documentations.

Thanks to whoever will answer and read all this.


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Tero Ahlfors
Re: Resolve and Monitor Color Correction
on May 9, 2018 at 10:15:13 am

[Andrea Franchini] " most people do not try to target a specific standard but instead they correct the display to be as neutral as possible"

I've never heard anything like this.

[Andrea Franchini] "Do you target specific standard?"

Yes. Because then you're working with a standard that can be replicated. If you make some display neutral in some setting then there's no saying what happens when you're viewing that file anywhere else say a post house or a theatre.

You will need:
-A Blackmagic I/O device/card to get your image from Resolve to an:
-External reference monitor. You don't need a 30 thousand euro one but one that's somewhat nice quality and specwise. Do not use the GUI monitor or ICC profiles in this. Your operating system and your GPU settings can affect what you're seeing in the GUI monitor. A proper projector (and the space for it) can get pretty gosh darn expensive.
-A probe. The Xrite i1 display pro is affordable and good enough.
-A calibration software. I use Lightillusion's Lightspace. There's also Calman and as a free option that I haven't used there's Displaycal.

There's all kinds of information on the Lightillusion site: https://www.lightillusion.com/tech_info.html


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Andrea Franchini
Re: Resolve and Monitor Color Correction
on May 21, 2018 at 1:08:00 pm

Hello, thanks you for the answer.

When I said some people target just a neutral color reproduction with their monitor I guess they're trying to reach the sRGB color space, since most monitor can only do that. That's why you read a lot about "making your monitor color neutral" and not "targeting a specific color space". But you're right.

What's the purpose of a blackmagic decklink card? Does it bypass the internal processing of the OS and the GPU by simply taking the raw image from davinci and display it on another monitor? This make everything more complicated and expensive since, as you suggested, I should avoid using my main display, which is connected to my gpu, and use an external one connected to the decklink.

When you calibrate your monitor with the probe and the software of your choice, let's say for rec 709, does the software offer you which standard are you trying to reach? But most of the time after the monitor calibration (the process of manually changing the monitor settings to get as near as possible to the target) there's the monitor profiling, which will return a lut most likely. At this point where am I suppose to put this lut? Inside davinci in the monitor 3d lut to correct the monitor colors? Inside windows? But as said this can cause errors since some apps simply ignore it.

Now I have my monitor calibrated to the rec 709 standard. Now whatever I do to my footage, contrast, gamma, color changes will look similar with every other display (of course this is unrealistic due different technologies, ...), but since my display is calibrated to 709, at least I know if the footage is watched on another calibrated monitor it should look the same right?

I understand that a decklink card would greatly improve the accuracy of the workflow, but for a beginner I think I should work with what I have and squeeze everything I can out of it.

What happen if I calibrate my monitor to SRGB? It shouldt be difficult for a software to convert it to rec709 right?

Again many questions and many doubts.
Thanks to you and to whoever asnwer all of this.


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Marc Wielage
Re: Resolve and Monitor Color Correction
on May 26, 2018 at 8:30:51 am

[Andrea Franchini] "What's the purpose of a blackmagic decklink card? Does it bypass the internal processing of the OS and the GPU by simply taking the raw image from davinci and display it on another monitor? This make everything more complicated and expensive since, as you suggested, I should avoid using my main display, which is connected to my gpu, and use an external one connected to the decklink."
Read pp. 667-668 of the Resolve 14.3 manual: "Limitations When Grading With the Viewer on a Computer Display." This goes into some detail why you cannot accurately monitor directly from the computer and operating system. You have to have a color-managed output, like one from a Blackmagic display card, preferably on a calibrated external Rec709 display.

You could make a joke that the Blackmagic display device is effectively a "dongle" for the program, since (to me at least) it only works properly with a card. But the truth is that you need a color-managed output where the video is unaffected by anything that happens within the operating system, so that you can reliably see the same picture day after day. Given how affordable the cards are, I think it's a small price to pay.


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