Final Explanation of Gamma and Color Shift Problems

Get answers to your questions about color grading, editing and finishing with DaVinci Resolve.
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Andrew Kolakowski

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Re: Final Explanation of Gamma and Color Shift Problems

PostSun Apr 19, 2020 7:37 pm

For those who need to play with headers (for whatever reasons) here is a new free tool which allows for modifications. It's PC+MAC (Linux version coming as well). Tool offers much more, but for those interested they should look at Metadata Editor tab:

viewtopic.php?f=3&t=111605

Soon it will support adding/removing/editing HDR headers in MOV as well. Those headers are quite new and about to be rectify by authority under 14496-12. Resolve already sets them (been added to FFmpeg as well), but not all values are correct. This will be first tool which will allow you easily adjust them.
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Andrew Kolakowski

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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Apr 27, 2020 9:47 am

Editing HDR metadata is now supported in v 0.4

viewtopic.php?f=14&t=112586
Last edited by Andrew Kolakowski on Thu Apr 30, 2020 12:40 pm, edited 1 time in total.
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Wayne Steven

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Re: Final Explanation of Gamma and Color Shift Problems

PostMon Apr 27, 2020 6:38 pm

That's cool.
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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Jacob Pritchard

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Re: Final Explanation of Gamma and Color Shift Problems

PostThu Apr 30, 2020 12:18 pm

That program looked interesting, and I bookmarked it specifically to come back and checkout. However, the forum post you linked @Andrew Kolakowski now seems to be done. Do you have a link to the program or any more info?
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Andrew Kolakowski

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Re: Final Explanation of Gamma and Color Shift Problems

PostThu Apr 30, 2020 12:40 pm

It has been moved by BM admins. Link updated.
You better bookmark this:
http://mogurenko.com
as those threads may not live long here.
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Wayne Steven

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Re: Final Explanation of Gamma and Color Shift Problems

PostThu Apr 30, 2020 5:06 pm

It's good to have any of these these things here, as they are features which BM can add to resolve.

There needs to be improvements suggestions (Suggestions, features and example apps that can be added) for each product category, and ones where we can restrict posting from those who 24/7 want to argue with thread starters.
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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Wayne Steven

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Re: Final Explanation of Gamma and Color Shift Problems

PostThu Apr 30, 2020 5:08 pm

Cool, they already have one 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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dariusii

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Re: Final Explanation of Gamma and Color Shift Problems

PostThu Apr 30, 2020 9:50 pm

>If you work in YRGB project, always set Timeline gamma to Rec.709 (Rec.709 (Scene)) and adjust final desired gamma look with CST Node..
YRGB (non color managed) project:
- Timeline set to Rec.709 (Scene)
- CST nodes set to: input Rec.709, Output Rec.709

Thanks, Dmitry.
Really, killed some project today with gamma 2.2 (project settings) in DR 16.2 and already had gave it to print.
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Dmitry Shijan

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Re: Final Explanation of Gamma and Color Shift Problems

PostFri May 01, 2020 9:46 am

dariusii wrote:>If you work in YRGB project, always set Timeline gamma to Rec.709 (Rec.709 (Scene)) and adjust final desired gamma look with CST Node..
YRGB (non color managed) project:
- Timeline set to Rec.709 (Scene)
- CST nodes set to: input Rec.709, Output Rec.709

Thanks, Dmitry.
Really, killed some project today with gamma 2.2 (project settings) in DR 16.2 and already had gave it to print.


Read first post. In 16.2 you may set Timeline to any color space and set render tags in render settings to Rec709.
Or you can set YRGB project timeline to Rec709 (Scene) and choose "Same as project" render tags.
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri May 01, 2020 6:22 pm

Call me stupid but I simply don't understand how to set Resolve to have proper output and preview in the viewer and via BM card. I need help and relatively simple answers about how to solve this.

Here is my setup:
1. iMac 2019
2. Ultrastudio HD
3. HP dream colour - set to rec709 and connected via HDMI to UltrastudioHD.

The closest I was to achieve similar results on the viewer and via Ultrastudio was to use resolve 16.0 and (use mac display colour for viewers) + Davinci YRGB (non-managed) but it was never 100% accurate. I skipped 16.1 and now in 16.2, I'm lost :-)

Can someone tell me how to set Resolve to have accurate preview via Ultrastudio and in the viewer (as close as possible)? Also how to set export settings to fix gamma shift and in general to make my video look the same as on Ultrastudio?
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri May 01, 2020 11:08 pm

I read the same thread and tried what you said. I come up with a different takeaway. My Question is about the color management page in Resolve 16.2.1. I rendered out the clip at the Resolve default Rec 709 Gamma 2.4 with the Color Science set to DaVinci YRGB. I then exported it using the two ways of doing it in Rec 709, project or render settings. Both of those looked the same and different from my initial render at gamma 2.4 in Quicktime player. I understand the difference there and also issues with QuickTime player. But when I bring both those clips back into Resolve along with my Resolve render at Gamma 2.4 and drop them on the timeline they all look the same. Until I go into the project settings / color management page. I then change the color science from DaVinci YRGB Color to DaVinci YRGB Color Managed. Now the two Rec 709 are lighter and the original Resolve 2.4 render is darker. In other words original default 2.4 render did not change in levels, but the Rec 709 got lighter. I have grabbed stills (attached) inside Resolve to show what happened when changing the color science to Managed. Now I tried all sorts of combos of Input, Timeline, Output settings and nothing made a difference as long as the color science was in Managed. As soon again doesn't matter what settings are put in I take the Color science and click off of Managed they all look the same now.

Why is this?
Attachments
Rec 709 default project 2.4.jpg
Rec 709 render loaded back into Resolve with color science set to default (non managed setting)
Rec 709 default project 2.4.jpg (69.1 KiB) Viewed 3415 times
Managed Rec 709.jpg
Color Science changed to Managed render loaded back into Resolve
Managed Rec 709.jpg (62.6 KiB) Viewed 3415 times
Original Graded 2.4.jpg
Original default Gamma 2.4 render loaded back into Resolve
Original Graded 2.4.jpg (65.38 KiB) Viewed 3415 times
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Andrew Kolakowski

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Re: Final Explanation of Gamma and Color Shift Problems

PostSat May 02, 2020 3:19 pm

If you graded with 2.4 gamma and tagged as Rec.709 (with Rec.709 gamma which is about 1.96), then of course it's going to look different in Resolve. Assume 2.4 gamma for the clip and it will look the same.
In proper/ideal world tagging always should match real content nature- so if you graded with 2.4 gamma then tagging should be exactly the same. It's the same as having interlaced footage tagged as progressive. It's a lie and if software relies on those tags then thing go simply wrong.
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 07, 2020 6:33 am

Hi everybody!
I had a color grading project in version 15. I upgraded to 16.2. And now the color is significantly different on the timelane and during export. I tried the recommendations from the topic header, set rec709 (scene), checked the use color mac os. Nothing helps, please tell me it is possible to return the color as in version 15 and display the project. New projects work well. The problem is with one project that I color grading in version 15.
I also tried to roll back to the old version, but he can not now open the project since the database has been updated.
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 07, 2020 11:26 am

batoev wrote:...now the color is significantly different on the timelane...

Are you sure? I have a pretty good visual memory, and I would still find hard remembering minute gamma / saturation differences, Unless you have "significant" differences, but then, how much of a difference are we talking here? Red turning orange would be a good one...
batoev wrote:...I tried the recommendations from the topic header, set rec709 (scene)...

No longer the case, you can keep your project in Rec709 Gamma 2.4, then choose the Rec709 tag on Delivery page. You'll have a nice 1-1-1 tagged video file. The main problem, however, is still monitoring Rec709 on an Apple P3 display.
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 07, 2020 12:35 pm

Is there any format to archive and lock the colours and levels of a project, revisits? But the again, that's probably what this whole thread is probably touching on.
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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Andrew Kolakowski

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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 07, 2020 12:40 pm

It's all just what you "see". Actual exported pixels are still the same, so nothing changes here :D
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 07, 2020 2:35 pm

Cosmin Hodiș-Mîndraș wrote:
batoev wrote:...now the color is significantly different on the timelane...

Are you sure? I have a pretty good visual memory, and I would still find hard remembering minute gamma / saturation differences, Unless you have "significant" differences, but then, how much of a difference are we talking here? Red turning orange would be a good one...

batoev wrote:...I tried the recommendations from the topic header, set rec709 (scene)...

No longer the case, you can keep your project in Rec709 Gamma 2.4, then choose the Rec709 tag on Delivery page. You'll have a nice 1-1-1 tagged video file. The main problem, however, is still monitoring Rec709 on an Apple P3 display.


Thank! Yes, the difference in shade - it was yellow, but it became more purple. I have some pieces that I managed to bring out in version 15, before the update. I did not change the nodes, they are the same as in 15, but after updating to 16.2, the color is significantly different. I followed your example and yes, it works well with new projects. But the project created in version 15 is different in color in version 16.

Is it possible to somehow roll back the database to version 15?

Снимок-экрана-2020-05-07-в-18.07.17.jpg
Снимок-экрана-2020-05-07-в-18.07.17.jpg (263.73 KiB) Viewed 3175 times

Снимок-экрана-2020-05-07-в-18.07.25.jpg
Снимок-экрана-2020-05-07-в-18.07.25.jpg (264.06 KiB) Viewed 3175 times

vs.jpg
vs.jpg (122.12 KiB) Viewed 3175 times
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Wayne Steven

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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 07, 2020 3:43 pm

Andrew Kolakowski wrote:It's all just what you "see". Actual exported pixels are still the same, so nothing changes here :D

To work on in 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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Re: Final Explanation of Gamma and Color Shift Problems

PostSun May 10, 2020 2:04 pm

Seems like things where changed again in few versions of Resolve 16, and "Use Mac display Colour profiles for viewers" option doesn't work as expected. For unknown reason it just don't match to native macOS video color management anymore. See this thread for details: viewtopic.php?f=21&t=113214

Resolve 16.2.1 Viewer with enabled "Use Mac display Colour profiles for viewers" don't match to rendered ProRes422HQ played back in QuickTimeX player on macOS 10.14.6
Image
Image

Also there is no more Rec709 (Scene) gamma timeline setting in 16.2.1. Only Rec709 gamma. Strange changes... Hope someone from Blackmagic support can explain what is going on.
Last edited by Dmitry Shijan on Wed May 13, 2020 1:50 pm, edited 1 time in total.
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Re: Final Explanation of Gamma and Color Shift Problems

PostWed May 13, 2020 1:46 pm

Dmitry Shijan wrote:..
Also there is no more Rec709 (Scene) gamma timeline setting in 16.2.1. Only Rec709 gamma. Strange changes... Hope someone from Blackmagic support can explain what is going on.


Rec.709 is same as Rec.709 (Scene). In the combined color space/gamma, it still says Rec.709 (Scene), to distinguish from Rec.709 Gamma 2.4.
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Dmitry Shijan

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Re: Final Explanation of Gamma and Color Shift Problems

PostWed May 13, 2020 1:50 pm

Yes, Seems it was my mistake about Rec.709 (Scene)
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri May 15, 2020 4:25 pm

Dmitry Shijan wrote:Seems like things where changed again in few versions of Resolve 16, and "Use Mac display Colour profiles for viewers" option doesn't work as expected. For unknown reason it just don't match to native macOS video color management anymore. See this thread for details: viewtopic.php?f=21&t=113214

Resolve 16.2.1 Viewer with enabled "Use Mac display Colour profiles for viewers" don't match to rendered ProRes422HQ played back in QuickTimeX player on macOS 10.14.6
Image
Image

Also there is no more Rec709 (Scene) gamma timeline setting in 16.2.1. Only Rec709 gamma. Strange changes... Hope someone from Blackmagic support can explain what is going on.


Thank you for posting about this, Dmitry. I noticed the exact same thing about the "Use Mac display Color profiles for viewers" Option and it doesn't work for me either. The exported files look completely different. A lot of people here say it's the monitor and such but it's not true because I reverted back to Resolve 16.0 and the exported files look exactly like the Resolve viewer in Quicktime. If anyone from Blackmagic is reading this, can you please implement whatever export method you guys used in 16.0 to the latest one? If it worked on that one, I'm sure you can make it work on this one. Thanks!
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Re: Final Explanation of Gamma and Color Shift Problems

PostSat May 16, 2020 1:47 pm

Maybe somebody know, what do need to use in Fusion for right viewing? Some lut, or what?
I'd test lut viewer in Fusion as liner to rec.709 lut, but image became more brighter, than on Edit/Color page.
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 6:19 am

Note a new option released in Resolve 16.2.2, released today:

----------------------------------------------------------------------
Resolve 16.2.2 introduces a new colorspace/gamma option named Rec.709-A which is compatible with how Apple frameworks handle Rec.709 Scene (1-1-1) tagged QuickTime files.

If you have a clip stored with the 1-1-1 profile and are using Resolve Color Management, please tag the input clip in media pool with the new Rec.709-A option.

If you are not using Resolve Color Management, you can set the timeline to Rec. 709-A.

The Resolve viewer should then match the QuickTime Player output. Please make sure “Use Mac Viewer Color Profile” in Preferences is enabled.

----------------------------------------------------------------------

This is from @Peter Chamberlain's message announcing 16.2.2 on the LiftGammaGain forum:

https://liftgammagain.com/forum/index.p ... sed.14518/
marc wielage, csi • VP/color & workflow • chroma | hollywood
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 7:11 am

Many many thanks Blackmagic for listening and adding Rec.709-A (1-1-1) in viewers/export in 16.2.2! works a charm : ) No 'gamma shift' is occurring and pure generator Rec.709 colors are staying within gamut while viewing on a P3 Mac display.

So many questions: What exactly is Rec.709-A? Why just now? The comments that 'this is not a Resolve issue' ;)

I have no reason to also use Final Cut Pro at this point :lol:
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 8:48 am

Christopher Dobey wrote:Many many thanks Blackmagic for listening and adding Rec.709-A (1-1-1) in viewers/export in 16.2.2! works a charm : ) No 'gamma shift' is occurring and pure generator Rec.709 colors are staying within gamut while viewing on a P3 Mac display.

So many questions: What exactly is Rec.709-A? Why just now? The comments that 'this is not a Resolve issue' ;)

I have no reason to also use Final Cut Pro at this point :lol:


Omg, it's finally solved... Thanks BM :D
As I can see, rec709-A it's the same rec709(Scene) – the same tags in output file and the same image on output. Except visible gamma inside DVR: with rec709-A inside DVR image look the same in output file in QT and YT.
https://www.youtube.com/channel/UCfEiKyCX4SThK_hwzGyzGVw
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 9:45 am

Not 100% ideal solution, but for those who want to see same preview inside Resolve and QTX is a "solve".

Custom 2.4 gamma based flagging also now matches 100% QTX preview (not 99%).
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 9:51 am

Christopher Dobey wrote:Many many thanks Blackmagic for listening and adding Rec.709-A (1-1-1) in viewers/export in 16.2.2! works a charm : ) No 'gamma shift' is occurring and pure generator Rec.709 colors are staying within gamut while viewing on a P3 Mac display.

So many questions: What exactly is Rec.709-A? Why just now? The comments that 'this is not a Resolve issue' ;)

I have no reason to also use Final Cut Pro at this point :lol:


Rec.709-A is just a gamma which matches one used in OSX engine for 1-1-1 tagging (which is around 1.96).
It's still not a real solution at all as this would require Apple input.
Real solution would be to grade to proper standard gamma (2.4 or 2.2) and then have correct preview in QTX, then youtube etc.
By using Rec.709-A it means you are grading to 1.96 gamma which is far from any preview device standard.
Last edited by Andrew Kolakowski on Tue May 19, 2020 11:39 am, edited 1 time in total.
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 10:40 am

Then they should call it Rec.709-Apple IOS, to remove confusion?
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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Andrew Kolakowski

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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 11:42 am

Value is taken from Rec.709 spec, but it should be never used for display device in 1st place.
Real solution is to Apple change/add new option to OSX color engine.
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 12:15 pm

So if I set my Resolve project to Rec.709-A, great, things will now look correct on QuickTime / macOS colour managed software.

But does that mean my outputs will, as a result, look wrong on non-colour managed software / Windows machines / Android devices/ broadcast equipment?
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Andrew Kolakowski

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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 12:54 pm

It won't be the same for sure as TVs etc. expect video to be graded to 2.4 gamma or 2.2 (not sure if anything at all expects 1.96). 1.96 is an old reverse value taken from Rec.709 spec for recording devices. It even didn't exist in Resolve and it probably never should be added.
For broadcast or any more serious project you can't grade to 1.96 gamma- this is plain wrong from the start. You have proper current standards which every studio uses and you're also expected to use them for any "proper" job. Never seen a setup based on 1.96 gamma :D
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 1:26 pm

Yeah, so when would one use Rec.709-A? Only situation I can see it's a good idea is if you know the content will only ever be viewed on an Apple device, right?
Last edited by videosoul on Tue May 19, 2020 2:25 pm, edited 1 time in total.
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 2:19 pm

Yes. It's all a workaround, not a proper solution (as it's not really in BM power to solve it properly).
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Dmitry Shijan

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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 8:58 pm

videosoul wrote:Yeah, so when would one use Rec.709-A? Only situation I can see it's a good idea is if you know the content will only ever be viewed on an Apple device, right?


Rec.709-A is for proper monitoring with enabled "Use Mac display Colour profiles for viewers"

Rec.709-A reads Rec709 gamma in bizzare Apple way
Rec.709 (Scene) reads Rec709 gamma in normal way

I guess in YRGB non color managed project it is OK to set timeline to Rec.709-A and enable "Use Mac display Colour profiles for viewers"

I guess you should NOT render to Rec.709-A and never use Rec.709-A as output gamma in CST node for render, because it is out of any common video specification.

If you don't use "Use Mac display Colour profiles for viewers" - just keep use Rec.709 (Scene)
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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 9:07 pm

That makes sense.

So, if you grade a project with Rec.709-A and "Use Mac display Colour profiles for viewers", but then output using "normal" Rec.709, should it look correct still on all devices?

No, right?

It'l still look different in QuickTime/Colour Managed software vs anything that either is strictly Rec.709 compliant, or doesn't use macOS ColourSync. Right?
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Dmitry Shijan

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Re: Final Explanation of Gamma and Color Shift Problems

PostTue May 19, 2020 9:28 pm

videosoul wrote:So, if you grade a project with Rec.709-A and "Use Mac display Colour profiles for viewers", but then output using "normal" Rec.709, should it look correct still on all devices?
It'l still look different in QuickTime/Colour Managed software vs anything that either is strictly Rec.709 compliant, or doesn't use macOS ColourSync. Right?


Rec.709-A only fix additional gamma shift problem between Resolve with enabled "Use Mac display Colour profiles for viewers" and macOS

QuickTime/Colour Managed still look different to non color managed. This is Apple's fault and there is nothing that we (or even Resolve developers) can do.
And even if Apple will fix this problem somewhere in future macOS version, there still be huge amount of people who use legacy OSes and old smartphones. So it will take another 10-20 years for complete refresh :)

I personally just always check rendered video on both Quicktime (color managed) and VLC (non color managed) players and adjust the grade of video somewhere in between (not too dark in VLC and not too bright in QuickTime).
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Re: Final Explanation of Gamma and Color Shift Problems

PostWed May 20, 2020 6:05 am

You know, the first time I saw this year's ago, I thought there was something wrong elsewhere, not in QuickTime, because Apple was projecting itself as competent. How could they stuff this up? It is really they that should not be accommodated, so that every body thinks the bad rendering on Apple products is their fault.

I've got another idea.
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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Re: Final Explanation of Gamma and Color Shift Problems

PostWed May 20, 2020 6:10 am

Is there a way to do normal workflow, than entice Apple products to re-interpret it to their environment, without having to write an extra filter program users have to install?

Actually, is there a way to script In footage to filter, realign or run a utility to correct the footage for Apple product usage?
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Re: Final Explanation of Gamma and Color Shift Problems

PostWed May 20, 2020 1:48 pm

Andrew Kolakowski wrote:It won't be the same for sure as TVs etc. expect video to be graded to 2.4 gamma or 2.2 (not sure if anything at all expects 1.96). 1.96 is an old reverse value taken from Rec.709 spec for recording devices. It even didn't exist in Resolve and it probably never should be added.
For broadcast or any more serious project you can't grade to 1.96 gamma- this is plain wrong from the start. You have proper current standards which every studio uses and you're also expected to use them for any "proper" job. Never seen a setup based on 1.96 gamma :D


Just to make it even more complicated.
I just found out that my Sony TV (Sony KDL-32WD755) when playing files internally uses 1.961 gamma (it also reports its profile to Mac as Rec.709-A with 1.961 gamma when connected over HDMI). Maybe this setting is not fully useless :)
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Re: Final Explanation of Gamma and Color Shift Problems

PostWed May 20, 2020 2:05 pm

Andrew Kolakowski wrote:
Andrew Kolakowski wrote:It won't be the same for sure as TVs etc. expect video to be graded to 2.4 gamma or 2.2 (not sure if anything at all expects 1.96). 1.96 is an old reverse value taken from Rec.709 spec for recording devices. It even didn't exist in Resolve and it probably never should be added.
For broadcast or any more serious project you can't grade to 1.96 gamma- this is plain wrong from the start. You have proper current standards which every studio uses and you're also expected to use them for any "proper" job. Never seen a setup based on 1.96 gamma :D


Just to make it even more complicated.
I just found out that my Sony TV (Sony KDL-32WD755) when playing files internally uses 1.961 gamma (it also reports its profile to Mac as Rec.709-A with 1.961 gamma when connected over HDMI). Maybe this setting is not fully useless :)


Not sure if this is related, but I've hooked up my Mac to a couple of broadcast monitors as a second OS display, but both looked ridiculously dark and lacking in saturation, despite being recognised in Display preferences with their own preset.
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Re: Final Explanation of Gamma and Color Shift Problems

PostWed May 20, 2020 2:27 pm

When you do it look at their profiles and inside you can see what gamma are they based.
Strange- they should not.
My TV is fine and matches Mac very well (my Mac is just set (by eye) to be warmer and TV is set to Film mode with all processing off). They are so close in look. I'm actually surprised how close.
I'm juts surprised TV is reporting 1.961 gamma, but this is probably same profile as Apple is using in OSX color engine.
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 21, 2020 5:07 am

Andrew Kolakowski wrote:Just to make it even more complicated.
I just found out that my Sony TV (Sony KDL-32WD755) when playing files internally uses 1.961 gamma (it also reports its profile to Mac as Rec.709-A with 1.961 gamma when connected over HDMI). Maybe this setting is not fully useless :)


I guess it just means that some TVs use same color management engine as macOS. Apple probably just attempt to distribute it's color management to other brands because wide gamut HDR TVs somehow should be color managed.

In color management systems Monitor ICC profile just designed to work in pair with color management engine. Monitor ICC profile is not related to video file profile.

By the way, HD 709-A.icc profile was distributed by Apple somewhere from 2010-2012. It is located at /System/Library/CoreServices/Resources/Profiles/HD 709-A.icc Here is example if someone want to check it.
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 21, 2020 12:46 pm

Dmitry Shijan wrote:I guess it just means that some TVs use same color management engine as macOS. Apple probably just attempt to distribute it's color management to other brands because wide gamut HDR TVs somehow should be color managed.


Doesn't it just mean the colour settings are being shared with the device via HDMI?
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 21, 2020 5:19 pm

Typically this is stored in TV.
It looks like even when I connect TV through BM card HDMI it still seems to use 1.961 gamma which is strange. At this point it has nothing to do with OSX anymore, so I would expect 2.2 or 2.4 gamma
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Re: Final Explanation of Gamma and Color Shift Problems

PostThu May 21, 2020 6:50 pm

Andrew Kolakowski wrote:Typically this is stored in TV.
It looks like even when I connect TV through BM card HDMI it still seems to use 1.961 gamma which is strange. At this point it has nothing to do with OSX anymore, so I would expect 2.2 or 2.4 gamma


Hmm, that is strange!
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri May 22, 2020 1:31 am

Andrew Kolakowski wrote:Typically this is stored in TV.
It looks like even when I connect TV through BM card HDMI it still seems to use 1.961 gamma which is strange. At this point it has nothing to do with OSX anymore, so I would expect 2.2 or 2.4 gamma


I remember someone telling me that, quote: “every TV has 2.2 gamma at the panel level”.
While this will be in te direction you see, it make non sense.
Even if the panel is “only” 1.96 or 2.2, that should not matter: a correct flagged broadcast signal can be simply converted from 2.4 to 2.2 (1.96) and still displayed correctly.

In other words, if a similar transform does not happen, you will not be able to map HDR PQ/HLG to a 2.2 (1.96) gamma panel... It’s math to me.

Now, Andrew, when you say 1.96 gamma, is that a measured with th probe profile giving the patches/grayscale?
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Re: Final Explanation of Gamma and Color Shift Problems

PostFri May 22, 2020 9:39 pm

I assume TVs were 2.2 based. Currently default is in more cases 2.4 (as you can find by reading those reviews: http://www.hdtvtest.co.uk/news/category/reviews)
All done by eye. I can see difference between 2.4 and 1.96 for 100%. Maybe TV was as 2.1 and then I may not necessarily would see difference that easily. It was done very quickly. What I was surprised though is how close preview was between TV and Mac (which I made bit warmer for my liking by eye). TV is basically default with Film setting. If we had all devices so close matching I would be quite happy as home user.

1.961 is what Apple uses in their color engine for 1-1-1 tag and also what TV reported to Mac in its profile. Other way of proving this is flagging files as 1-2-1 with 1.96 gamma tag. It will look 100% identical to one tagged as 1-1-1 (of course if you change gamma from 1.96 then it doesn't match anymore).
I wonder if I would get the same when connected to a PC.
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun May 24, 2020 4:04 pm

Sorry, no, that is not the way to do science!...(LOL)...

Send a proper 10/20 patches Via decklink to the TV and measure them and see the gamma curve. That is the right way....
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Re: Final Explanation of Gamma and Color Shift Problems

PostSun May 24, 2020 4:29 pm

I don't care much about what this TVs is using as I don't use it for anything.
Can't even watch todays TV either as in 90% it's pure crap (at least in Poland, but UK wasn't much better either with Love Island etc. )
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