Final Explanation of Gamma and Color Shift Problems

Get answers to your questions about color grading, editing and finishing with DaVinci Resolve.
  • Author
  • Message
Offline

producerguy

  • Posts: 72
  • Joined: Tue May 07, 2019 1:20 am
  • Real Name: Robert Lane

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,
Offline

Wayne Steven

  • Posts: 2496
  • Joined: Thu Aug 01, 2013 3:58 am
  • Location: Earth

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.
Often people deceive themselves so much they do not understand, even when the truth is explained to them.
Offline

producerguy

  • Posts: 72
  • Joined: Tue May 07, 2019 1:20 am
  • Real Name: Robert Lane

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.
Offline

Wayne Steven

  • Posts: 2496
  • Joined: Thu Aug 01, 2013 3:58 am
  • Location: Earth

Re: Final Explanation of Gamma and Color Shift Problems

PostFri Feb 14, 2020 3:35 pm

Ok.
Often people deceive themselves so much they do not understand, even when the truth is explained to them.
Offline

Vit Reiter

  • Posts: 462
  • Joined: Mon Sep 04, 2017 5:36 pm

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.
DaVinci Resolve 16.1.2 Studio
Mac Pro 2013, AMD FirePro D700, 64GB RAM, macOS Mojave 10.14.6
iMac 2017, Radeon Pro 575, 24GB RAM, macOS High Sierra 10.13.6

Film Editor, Colorist, DIT, Encoding technician
linkedin.com/in/vít-reiter-film-editor
Offline
User avatar

Dmitry Shijan

  • Posts: 1035
  • Joined: Wed Sep 17, 2014 7:15 pm
  • Location: UA

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.
All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
Offline

koraybirand

  • Posts: 2
  • Joined: Tue Feb 11, 2020 8:55 pm
  • Real Name: Koray Birand

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
Koray Birand
www.koraybirand.co.uk
Offline

Vit Reiter

  • Posts: 462
  • Joined: Mon Sep 04, 2017 5:36 pm

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.
DaVinci Resolve 16.1.2 Studio
Mac Pro 2013, AMD FirePro D700, 64GB RAM, macOS Mojave 10.14.6
iMac 2017, Radeon Pro 575, 24GB RAM, macOS High Sierra 10.13.6

Film Editor, Colorist, DIT, Encoding technician
linkedin.com/in/vít-reiter-film-editor
Offline
User avatar

Dmitry Shijan

  • Posts: 1035
  • Joined: Wed Sep 17, 2014 7:15 pm
  • Location: UA

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
All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
Offline

Wayne Steven

  • Posts: 2496
  • Joined: Thu Aug 01, 2013 3:58 am
  • Location: Earth

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?
Often people deceive themselves so much they do not understand, even when the truth is explained to them.
Offline
User avatar

Dmitry Shijan

  • Posts: 1035
  • Joined: Wed Sep 17, 2014 7:15 pm
  • Location: UA

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)
All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
Offline
User avatar

waltervolpatto

  • Posts: 7390
  • Joined: Thu Feb 07, 2013 5:07 pm
  • Location: 1146 North Las Palmas Ave. Hollywood, California 90038 USA

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
SuperServer 5039AD-I
C9X299-PGF - DDR4-2400 16x4 GB
i9-7920xCPU 12c 2.90GHz Water cooled
2x 1080ti DeckLink Studio 4K (11.4)
W10-1903 - BMR St. 16.1.2.026
nvidia: 441.66 studio
Offline
User avatar

Dmitry Shijan

  • Posts: 1035
  • Joined: Wed Sep 17, 2014 7:15 pm
  • Location: UA

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
All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
Offline
User avatar

waltervolpatto

  • Posts: 7390
  • Joined: Thu Feb 07, 2013 5:07 pm
  • Location: 1146 North Las Palmas Ave. Hollywood, California 90038 USA

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.....
SuperServer 5039AD-I
C9X299-PGF - DDR4-2400 16x4 GB
i9-7920xCPU 12c 2.90GHz Water cooled
2x 1080ti DeckLink Studio 4K (11.4)
W10-1903 - BMR St. 16.1.2.026
nvidia: 441.66 studio
Offline
User avatar

Dmitry Shijan

  • Posts: 1035
  • Joined: Wed Sep 17, 2014 7:15 pm
  • Location: UA

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.
All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
Offline
User avatar

Dmitry Shijan

  • Posts: 1035
  • Joined: Wed Sep 17, 2014 7:15 pm
  • Location: UA

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.
All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
Previous

Return to DaVinci Resolve

Who is online

Users browsing this forum: Christopher Dobey, Dieter Scheel, Ian Henderson, KatsPurr, MSN [Bot], rhgkswhd and 77 guests