Final Explanation of Gamma and Color Shift Problems

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producerguy

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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 14, 2020 3:42 am

koraybirand wrote:My solution is as follows..
Source file in QTPlayer
Video and Color Monitor in Resolve
Exported rendered file
Exact match..
Image

the lut file needed is found on this post but just in case if you need it:
https://drive.google.com/open?id=1FFUbw ... gMH0LFfgQR

Koray Birand


Koray, would you be so kind as to send a link to that screenshot or, upload a larger version? That file is too small to actually see text.

Cheers,
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Wayne Steven

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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 14, 2020 8:40 am

Robert, click on it and enlarge it. I can read the text here.
aIf you are not truthfully progressive, maybe you shouldn't say anything
bTruthful side topics in-line with or related to, the discussion accepted
cOften people deceive themselves so much they do not understand, even when the truth is explained to them
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producerguy

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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 14, 2020 2:23 pm

Wayne Steven wrote:Robert, click on it and enlarge it. I can read the text here.


Tried that - not clickable for me.
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 14, 2020 3:35 pm

Ok.
aIf you are not truthfully progressive, maybe you shouldn't say anything
bTruthful side topics in-line with or related to, the discussion accepted
cOften people deceive themselves so much they do not understand, even when the truth is explained to them
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Vit Reiter

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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 14, 2020 4:15 pm

Dmitry Shijan wrote:... metadata(timeline) set to...
Dmitry,

are you sure Timeline Color Space parametter is putting metadata to exported video file?

I think this is a workspace in which DaVinci processes color editing of video. The Output Color Space parameter writes metadata to the exported file not Timeline Color Space.

The Color Output Space is used for correct matching viewing on your monitor (mostly Rec.709, Gamma 2.2) and before exporting of a video file you only change the Color Output Space setting to target destinations such as YouTube, broadcast, cinema, etc., because just this parameter puts metadata to exported video file.
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Dmitry Shijan

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Re: Final Explanation of Gamma and Color Shift Problems

PostSat Feb 15, 2020 12:29 am

Vit Reiter wrote:
Dmitry Shijan wrote:... metadata(timeline) set to...
Dmitry,

are you sure Timeline Color Space parametter is putting metadata to exported video file?

I think this is a workspace in which DaVinci processes color editing of video. The Output Color Space parameter writes metadata to the exported file not Timeline Color Space.

The Color Output Space is used for correct matching viewing on your monitor (mostly Rec.709, Gamma 2.2) and before exporting of a video file you only change the Color Output Space setting to target destinations such as YouTube, broadcast, cinema, etc., because just this parameter puts metadata to exported video file.


Timeline Color Space parameter is putting metadata to exported video file only if you use YRGB (aka non color managed) project setting.
In this workflow you can manipulate within timeline with LUTs or color space transform nodes as you like. Your actual color space is not limited by timeline.

But If you use YRGB Color managed project setting, your input color space always being transformed to Timeline color space, and next transformed to Output color space. In this scenario "Output color space" putting metadata to exported video file.

Those things where already described in first post. Just take a breath and read it.
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Re: Final Explanation of Gamma and Color Shift Problems

PostSat Feb 15, 2020 9:29 am

producerguy wrote:
koraybirand wrote:My solution is as follows..
Source file in QTPlayer
Video and Color Monitor in Resolve
Exported rendered file
Exact match..
Image

the lut file needed is found on this post but just in case if you need it:
https://drive.google.com/open?id=1FFUbw ... gMH0LFfgQR

Koray Birand


Koray, would you be so kind as to send a link to that screenshot or, upload a larger version? That file is too small to actually see text.

Cheers,


Sure here is the direct link :
https://i.imgur.com/Fef91bf.jpg
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Re: Final Explanation of Gamma and Color Shift Problems

PostSat Feb 15, 2020 9:38 pm

Dmitry Shijan wrote:Timeline Color Space parameter is putting metadata to exported video file only if you use YRGB (aka non color managed) project setting.
Color Science YRGB can be managed or unmanaged. If you write YRGB only nobody knows what do you think :-)

It should be noted that if a Color Science YRGB Unmanaged settings is active then the Output Color Space parameter writes metadata to exported file. This is the same like in managed profile. What is different in unmanaged YRGB Color Science is that the Timeline Color Space sets all three parameters (Input, Timeline and Output Color Space) together. Output Color Space is that parameter which puts metadata to exported file not Timeline Color Space.

We need to be precise so that we do not cause chaos in an already complex problem.
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Dmitry Shijan

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Re: Final Explanation of Gamma and Color Shift Problems

PostSat Feb 15, 2020 11:38 pm

Not sure if i understand you exactly, but seems you are wrong.
YRGB (non color managed) Color Science don't sets all three parameters (Input, Timeline and Output Color Space) together. It don't "sets" nothing and don't do any color transformations at all. It is like empty space. In this YRGB workflow you need manually set everything as you like - add proper input LUT or CST node and add output LUT or CST node.

"YRGB color managed" always do all color transforms under the hood in more simpler but less flexible way. If you disable Input and Output setting, "YRGB color managed" will act same as "YRGB (non color managed)"

-------

If Setting named "YRGB" in proejct settings, so i use same YRGB (or sometimes for better definition YRGB (non color managed)) name in article.

If Setting named "YRGB color managed" proejct settings, so i always name it "YRGB color managed".

Too bad that Resolve developers decide to use two so similar and not too common names for two completely different workflow logics. Those confused variations around "YRGB" definition in project settings should be simply renamed to something like:
Global project color management OFF
Global project color management ON
Global project color management ACES
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun Feb 16, 2020 7:23 am

The thread is probably big enough not to be read easily, but big enough to have the very technique is it's benefits/disadvantages summarised in the first post?
aIf you are not truthfully progressive, maybe you shouldn't say anything
bTruthful side topics in-line with or related to, the discussion accepted
cOften people deceive themselves so much they do not understand, even when the truth is explained to them
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Dmitry Shijan

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Re: Final Explanation of Gamma and Color Shift Problems

PostWed Feb 19, 2020 11:34 pm

Vit Reiter wrote:We need to be precise so that we do not cause chaos in an already complex problem.


:arrow: Here is new ultra short guide:

To avoid gamma shift problems and preserve 1-1-1 tags in YRGB project:
- Set Timeline to Rec.709 (Rec.709 (Scene))
- Adjust final desired look with input/output CST Nodes or LUTs

To avoid gamma shift problems and preserve 1-1-1 tags in YRGB Color Managed project:
- Set Output in project settings to Rec.709 (Rec.709 (Scene))
- Right click on each clip and select proper input profile depending of your source (For unknown reason Resolve by default assigns Rec709/gamma 2.4 input to any ProRes file, so you need to change it manually)
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 21, 2020 12:21 am

Dmitry,
It don't "sets" nothing and don't do any color transformations at all. It is like empty space.


That is incorrect: timeline color space is used fo DCP creation, Tag on quicktimes, quick OFX color transform (default) and to change the color/gamut of a single node
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Dmitry Shijan

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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 21, 2020 1:31 am

I never deal with DCP creation before, so i can't confirm or deny this. But yes, there are also some limitations when you set workflow like explained earlier.
You can't use quick change node gamma/color space (right-click on node and set gamma/color) because it always use timeline color space/gamma as transform input. You should use "legacy" way with dual CST nodes which transform from your desired working space and back:
(CST node log to lin -> gain adjustment -> CST node lin to log)

Using timeline for setting metadata tags is not a perfect way to go, but i can't see alternative yet. Current color management logic in Resolve is very far from perfect and it should be redesigned as soon as possible to match modern reality. It should provide flexible flagging options in the render settings as requested here viewtopic.php?f=33&t=101089
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 21, 2020 4:51 am

Dmitry Shijan wrote:You should use "legacy" way with dual CST nodes which transform from your desired working space and back:
(CST node log to lin -> gain adjustment -> CST node lin to log)


that is bogus: the timeline color space IS DESIGNED to work in conjunction with the node color space change to allow a single operation to be done WITHOUT going with three nodes.

I DO NOT want to use the "legacy way": the whole introduction of color space transform in the single nodes is exactly to AVOID making three nodes.....
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 21, 2020 5:09 am

waltervolpatto wrote:
Dmitry Shijan wrote:You should use "legacy" way with dual CST nodes which transform from your desired working space and back:
(CST node log to lin -> gain adjustment -> CST node lin to log)


that is bogus: the timeline color space IS DESIGNED to work in conjunction with the node color space change to allow a single operation to be done WITHOUT going with three nodes.

I DO NOT want to use the "legacy way": the whole introduction of color space transform in the single nodes is exactly to AVOID making three nodes.....


Currently it all looks like sort of unfinished design. I'll be happy to set and forget timeline to wide gamut color space and use all things as is was designed. It is simpler, less additional CST nodes. Actually everything worked perfectly like this until Resolve v16 start to add metadata tags dictated by timeline color space and goes into crazy problems with gamma shifts on Mac.
Resolve just should provide us flexible custom flagging options in the render settings. It was VERY VERY bad idea in Resolve 16 to use Timeline color space settings in YRGB project to automatically set tags for rendered video.
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 21, 2020 5:15 am

By the way, some things are still don't works with quick right click node gamma/color space. For example if for some reason you want to use ColorMatch tool inside different color space/gamma, you still need to use 3 nodes chain. (CST node -> Color Match Node -> CST node).
ColorMatch node just ignores right click node gamma/color space setting.
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu Mar 05, 2020 1:05 pm

Hi Dmitry, and thank you for this great thread. Im having trouble with my export, as im noticing slight magenta color shift and washed out blacks.

Im working on alexa mini log footage on YRGB and timeline set to REC709 gamma 2.4

My working space is set to video data. And my output is rendered as ProRes 422HQ data leves on auto.

Im monitoring my grade on external monitor Eizo CG247x which is receiving signal through Intensity 4K pro.

We calibrated monitor (with external hardware) and im using monitoring LUT inside of the resolve which is calibrated for Limited range on gamma 2.4

Rendered output file looks different tho...

Invisor is reading on file
"Color primaries: BT.709
Matrix coefficients: BT.709"

File looks different and have color cast when played on mac preview, quick time, and vlc player.


Attached screenshot
This is how picture looks like in resolve viewer and on external monitor
Image

And this is how it looks like when rendered (note slight magenta shift is visible with washed out blacks) IT almost appear like red color is boosted.
Image
P.s. when i load rendered footage back into resolve its appearing normal without shift again.
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu Mar 05, 2020 8:35 pm

Trust your BM preview on calibrate monitor and don't worry much about look on Mac screen. It will always look different against your Eizo (regardless all tagging issues).
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Mar 06, 2020 5:45 am

Just to blow up this thread:

New in 16.2

• Support for overriding the color space and gamma tags in render settings.
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Mar 06, 2020 5:47 am

Dusan Bartolovic wrote:Hi Dmitry, and thank you for this great thread. Im having trouble with my export, as im noticing slight magenta color shift and washed out blacks.

1. Read the first post in this thread to understand things.
2. Try to setup your project timeline to Rec709 (scene) as described there to avoid additional gamma shifts during Youtube/Handbrake transcodings.
3. QTX is the only one color managed video player yet, so QTX player on mac always output slightly different colors and gamma compare to non color managed players like VLC.
4. If you on Mac, try to calibrate your monitor to sRGB gamma. From my personal experience Mac OS system wide color management is always expect sRGB monitor gamma. Monitors calibrated to camma 2.2 or 2.4 may produce strange tonal shifts.

Eizo CG247x + Intensity 4K pro is different story, this setup is not based on MacOS color management so it is probably require different calibration and settings. Sort of LUT based correction inside Resolve on LUT based calibration uploaded to Eizo monitor if possible. It can be done with DisplayCAL and there are a lot of video tutorials online.
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Mar 06, 2020 5:47 am

Dwaine Maggart wrote:Just to blow up this thread:

New in 16.2

• Support for overriding the color space and gamma tags in render settings.


PERFECT!
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Mar 06, 2020 7:13 am

Dwaine Maggart wrote:"Just to blow up this thread"


HAHA Dwaine you're the man :lol: and thank you Blackmagic for the update!
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Mar 06, 2020 11:06 am

Dmitry Shijan wrote:
Dwaine Maggart wrote:Just to blow up this thread:

New in 16.2

• Support for overriding the color space and gamma tags in render settings.


PERFECT!


Useful but solves not much.
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Mar 06, 2020 2:45 pm

Andrew Kolakowski wrote:
Dmitry Shijan wrote:
Dwaine Maggart wrote:Just to blow up this thread:

New in 16.2

• Support for overriding the color space and gamma tags in render settings.


PERFECT!


Useful but solves not much.


Yes it does.
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Mar 06, 2020 2:51 pm

Fact that you can grade to 2.4 but tag file as Rec.709 (1-1-1) won't solve preview difference.
Until Apple (and others) changes math behind Rec.709 preset or introduce new tag for 2.2 and 2.4 gamma which all providers will preserve nothing will change.
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri Mar 06, 2020 4:20 pm

Lol, I was not think about that, but it should decouple the color space used for the grade to the one tagged to the export file.

So, at least within the box, less confusion.
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Re: Final Explanation of Gamma and Color Shift Problems

PostSat Mar 07, 2020 12:36 am

Following this post for a long time, the 16.2 release finally adds the option of NCLC tags.
Share my Settings:
I work on the Mac's built-in screen.
Display configuration file using the default "Color LCD"(Display P3)
[Use Mac Display Color Profiles for viewers] Yes
Color Science:DaVinci YRGB
Timeline Color Space:Rec.709 Gamma 2.4
Deliver Page
Color Space Tag:Rec.709
Gamma Tag:Gamma 2.4
I opened it in QuickTime and got the same color as the viewer.
I think understanding the working principle of NCLC Tag is the key to solve the problem. Baselight's video makes it pretty clear.
Thanks for sharing.
Because my English is poor, so most of the text used translation software...... :D
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Re: Final Explanation of Gamma and Color Shift Problems

PostSat Mar 07, 2020 2:10 pm

Dwaine Maggart wrote:Just to blow up this thread:

New in 16.2

• Support for overriding the color space and gamma tags in render settings.


How?

I just see "same as project" for both gamma and color space tags.
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Re: Final Explanation of Gamma and Color Shift Problems

PostSat Mar 07, 2020 4:33 pm

franciscovaldez wrote:
Dwaine Maggart wrote:Just to blow up this thread:

New in 16.2

• Support for overriding the color space and gamma tags in render settings.


How?

I just see "same as project" for both gamma and color space tags.


did you try to choose something else?
if it is [same as project] it take the timeline tag in the settings (in non RCM workflow), now you can decouple that.
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Re: Final Explanation of Gamma and Color Shift Problems

PostSat Mar 07, 2020 4:35 pm

Dwaine Maggart wrote:Just to blow up this thread:

New in 16.2

• Support for overriding the color space and gamma tags in render settings.


That is handy, however a step further is to have the [ofx color transform] tool also in the delivery page to avoid timeline duplication when you have to deliver multiple masters (709/xyz/p3dci and so on) from a single source.....
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun Mar 08, 2020 2:56 am

Dwaine Maggart wrote:• Support for overriding the color space and gamma tags in render settings.
It is useful that in Preferences I can set Monitor Output (usually Rec.Gamma 2.2 or sRGB) and export it independently to Gamma 2.4 for broadcast or cinema, but it does not solve the problem that DaVinci cannot export a video with a transformation characteristic for Rec.709 Gamma 2.4 and a bug that writes SD data to the Transfer characteristic Rec.709 Gamma 2,2.
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun Mar 08, 2020 9:31 am

Good afternoon, dear colleagues. Please help us solve the problem related to incorrect display of gamma and color in the DaVinci Resolve viewport. The material in DR doesn't look like it should... For the referent, I give an example with the same development LUT in FCPX (FCPX is displayed correctly) . I beg you to help me, I will soon hand over the project to the customer and I needed to use face retouching in DR...
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun Mar 08, 2020 10:38 am

Good day help solve the problem with incorrect display of gamma and color in the DR viewer window. This problem occurred when I bought a MacBook pro 16 (the default monitor profile is DCI-P3) the Rest of the settings will try to attach screenshots in comparison with FCPX....
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun Mar 08, 2020 12:17 pm

Vit Reiter wrote:.. but it does not solve the problem that DaVinci cannot export a video with a transformation characteristic for Rec.709 Gamma 2.4 ....


It can and it does it for 2.4 based gamma projects.
Resolve just sets tags- what later software does with them it has nothing to do with Resolve anymore.
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun Mar 08, 2020 2:30 pm

waltervolpatto wrote:
franciscovaldez wrote:
Dwaine Maggart wrote:Just to blow up this thread:

New in 16.2

• Support for overriding the color space and gamma tags in render settings.


How?

I just see "same as project" for both gamma and color space tags.


did you try to choose something else?
if it is [same as project] it take the timeline tag in the settings (in non RCM workflow), now you can decouple that.


I tried but I'm not sure how it's supposed to work.

For example for gamma, I only see two viable choices, "same as project" or "2.4". Since my project is 2.4, in theory, both choices should render the same result.

All other choices on the dropdown don't seem to apply to me. Unless I'm missing something.

I don't see a plain and simple "no tag" choice.
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun Mar 08, 2020 4:24 pm

Resolve 16.2 YRGB project:
Set Timeline to to native BMDfilm log or whatever you like.
For normal export set timeline CST node to Rec709.
Set Color Space and Gamma tags in render settings to Rec709.
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun Mar 08, 2020 5:07 pm

One little problem is still there: In YRGB project “Use Mac Display Color Profiles for Viewers” in preferences seems still hard linked to Timeline color space.
In perfect world i guess “Use Mac Display Color Profiles for Viewers” input should be linked to Render Tags. Or it could be separate user defined Gamma and Color Space Tags settings in preferences near “Use Mac Display Color Profiles for Viewers” checkbox. This may allow to setup native mac OS color management for wide gamut displays in more flexible way.
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 12:19 pm

Andrew Kolakowski wrote:
Vit Reiter wrote:.. but it does not solve the problem that DaVinci cannot export a video with a transformation characteristic for Rec.709 Gamma 2.4 ....
It can and it does it for 2.4 based gamma projects.
Resolve just sets tags- what later software does with them it has nothing to do with Resolve anymore.
Can you list one program (except DaVinci) that reads the transfer characteristic of exported video from DaVinci to Rec.709 Gamma 2.4?

E.g. these programs doesn't read transfer characteristic:

Interra Baton
Switch
Media Info
etc.
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 1:46 pm

Baselight, JesExtensifier, whole OSX color engine.
It's because most companies didn't/don't care about those headers and even if they do they don't implement it according to full spec, but just small portion of it.
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 2:40 pm

In current reality SDR HD video with any custom tags except Rec709 (or 1-1-1) will always add a risk of gamma shifts during transcodings. During all this discussion i still can't understand what is the practical point of gamma 2.4 for delivery and why some of you so want to use that custom gamma 2.4 tags into your workflow? Why don't tag it as linear or Cineon curve tag :)? Those tags also exists in quicktime/mp4 specification but no one except Mac OS quicktime X player will read them because it is totally useless tech for SDR video. Those custom tags only add additional mess into already totally messy and overcomplicated video world.

Just stay within commonly accepted and safe Rec709 (or 1-1-1) render tags and any of your SDR HD videos will look OK on any OS and any hardware/software/smartphone, on color managed and non color managed video players.
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 4:14 pm

Dmitry Shijan wrote:In current reality SDR HD video with any custom tags except Rec709 (or 1-1-1) will always add a risk of gamma shifts during transcodings. During all this discussion i still can't understand what is the practical point of gamma 2.4 for delivery and why some of you so want to use that custom gamma 2.4 tags into your workflow? Why don't tag it as linear or Cineon curve tag :)? Those tags also exists in quicktime/mp4 specification but no one except Mac OS quicktime X player will read them because it is totally useless tech for SDR video. Those custom tags only add additional mess into already totally messy and overcomplicated video world.

Just stay within commonly accepted and safe Rec709 (or 1-1-1) render tags and any of your SDR HD videos will look OK on any OS and any hardware/software/smartphone, on color managed and non color managed video players.


In my case, I grade on a 2.4 environment (sometimes 2.6) and I want to export without tags because Quicktime misinterprets my tags. And as far as I understand, if choose any other tags like linear or cineon, will get also different results, because there's no correlation with my actual working gamma.

What I think I need is a way to export with no tags. Or will this introduce new problems?
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 4:36 pm

What exactly means "2.4 environment (sometimes 2.6)"?
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 4:50 pm

I mean that my monitor is calibrated for 2.4.

And that sometimes I work on P3 2.6 environments.

Using RCM let's me switch from one viewing environment to the other, keeping my grades the same.

This for example would allow me to grade a project on a Rec709 2.4 monitor, then go to a P3 2.6 projector for a trim pass, just changing my desired output on RCM keeping the timeline the same.
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 5:16 pm

Monitor calibration is just a monitor calibration. Monitor calibration should match your monitor but you never need to adjust rendered video to your monitor calibration.
If my monitor calibrated to sRGB gamma (because i feel that current versions of mac OS color management works better with sRGB monitor gamma), it doesn't means that i need to render video with sRGB gamma and put some crazy custom sRGB tags inside that video.

Until you do things inside some very specific closed edit-render-view system. Your rendered video color space and gamma should always match common industry standards. So other people can see it without dramatic gamma and color shifts on various different devices.

Monitor calibration, project/timeline color settings and rendered video settings are 3 completely independent parts.

And please read explanation in the first post. You find there some info about monitor calibration as well.
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 5:33 pm

Your workaround is purely for Mac. It just gives you same view on Mac as you see in Resolve, but this is not a view which you will see on reference monitor (or PC or when played with eg TV internal player).
You grade to 1.96 gamma which is not any proper standard for display.
Last time- it's work around which solves not much+ gives you files which are graded to a custom gamma. Nothing that good at all. If anything you may be better to grade to 2.2 or sRGB as then your preview error on Mac vs. other devices will be in the middle.
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 5:41 pm

I don't use “Use Mac Display Color Profiles for Viewers” and don't use Quicktime player. I rely on sRGB gamut monitor, Resolve viewer and VLC player on Mac, so video in this chain should look exact same as on Windows.

Mac specific 1.96 gamma read shift only exists when you apply “Use Mac Display Color Profiles for Viewers” or playback video with Quicktime X player. Correct?
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 5:43 pm

franciscovaldez wrote:I mean that my monitor is calibrated for 2.4.

And that sometimes I work on P3 2.6 environments.

Using RCM let's me switch from one viewing environment to the other, keeping my grades the same.

This for example would allow me to grade a project on a Rec709 2.4 monitor, then go to a P3 2.6 projector for a trim pass, just changing my desired output on RCM keeping the timeline the same.


You are correct.
Tags should match gamma which video was graded too. That's the whole point of them.
Problem that only few apps can properly process 2.2 or 2.4 gamma based files is a state of industry.
Have 2.6 graded files tagged as Rec.709 Scene solves nothing. Preview will be very bad. You would have to graded to Rec.709 Scene, but this is not gamma which should be used for any grading. Circle closes. Until Apple and other fixes/updates color tagging system to much current standard there isn't really a proper solution.
Last edited by Andrew Kolakowski on Mon Mar 09, 2020 5:51 pm, edited 2 times in total.
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 5:46 pm

Dmitry Shijan wrote:I don't use “Use Mac Display Color Profiles for Viewers” and don't use Quicktime player. I rely on sRGB gamut monitor, Resolve viewer and VLC player on Mac, so video in this chain should look exact same as on Windows.

Mac specific 1.96 gamma read shift only exists when you apply “Use Mac Display Color Profiles for Viewers” or playback video with Quicktime X player. Correct?


Ok- this is slightly different then.
You still going to have gamut problem as Apple screens are vide gamut. Yo have to correct this with Resolve preview LUTs etc.
Everyone who will watch your work on YouTube with Safari (and 90% Mac uses will) will have very bad preview. We are back to the beginning.
You are assuming many things- we are talking about producing files which work properly on any device (skipping accuracy of the screens).
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 5:51 pm

Please don't forget that solution discussed in this thread is just about to avoid additional gamma shifts between Resolve rendered video, Handbrake-like transcoded video and Youtube-like uploaded video.
It will not fix global cross platform color management problem.
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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Mar 09, 2020 5:57 pm

Any ideas how video color management works on Android?
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