- This topic has 18 replies, 5 voices, and was last updated 8 years, 1 month ago by
.
-
Posts
-
I own an Eizo CS240 which is calibrated internally to full native gamut and D65 and gamma 2.2 and comes with its matrix ColorNavigator ICM profile. It is connected form my computer (AMD GPU) with Displayport.
Although this computer is mostly for photo editing in Windows, I want to use it “as is” all the time (full gamut, no recalibrations involved): internet (Firefox is color managed), PDF documentation (Acrobat is color managed)… and video.Here it comes the problem, video. My setup is:
-Media player classic HC as player
-LAV codecs as video decoder (0-255 YUV->RGB conversion)
-madVR for color management, 0-255 range and LUT3D file for Rec709When configuring that setup:
-If I use your software to create LUT3D, it does it wrong, since your LUT3D is 16-235 -> 16->235. In that setup if I open a DVD/MP4 with R,G,B Rec709 primaries & gradients, AdobeRGB green is shown for Rec709 green and CS240’s native red is shown for Rec709 red… but all colors (gradients) lower than 235 show in a Rec709 gamut, I mean not oversaturated. It seems that 235-255 values go “not color managed”.
-If I use yCMS bundled in madVR, set my XYZ for RGB primaries it computed a LUT3D (madVR lut3d format), and all Rec709 test (DVD or MP4 file) shows proper “rec709 like” colors. Good
-If I use command line collink with “-en -En”, I mean full range LUT3D for madVR, all Rec709 test (DVD or MP4 file) shows proper “rec709 like” colors. Same look as with yCMS. Good.
Since your software “DisplayCAL-3DLUT-maker.exe” does not allow me to do full range… I need to to that in command line with ArgyllCMS (Path, folders… not as fast as with your GUI)
It does not matter if I use Color Navigator matrix profile to feed DisplayCAL-3DLUT-maker.exe or if I create a ICM profile with DisplayCAL configured to madVR output, measure, profile, etc, a madVR 16-235 LUT3D always gives bad colors, oversaturaed if content is near Rec709 primaries (>235 “RGB equivalent” values)So my questions/request are:
-Is this bad behaviour of DisplayCAL genetared LUT3D caused by my LAV decoder configuration to 0-255 ?
-IMHO, your DisplayCAL-3DLUT-maker.exe should allow to create full range to full range madVR LUT3D. There are computer users with widegamut monitor who will need that feature for Rec709 video play. Maybe to use 16-235 LUT3D for madVR is totally wrong for computer monitors and “full range input TV” users had not noticed it because their R & G primaries are so close to Rec709 that they did not notice that near rec709 red & green colors go “not color managed” in such 16-235 LUTs.
-What is best setup for a widegamut monitor (calibrated internally to AdobeRGB gamut or full native gamut) used for Rec709 video play?
Is there other setup better than LAV 0-255 -> madVRLUT3D 0-255->0-255 (collink -en -En) mapping Rec709 to my ICM profile-> madVR 0-255 ?Thanks in advance
MadVR 3D LUTs need to be always encoded with TV levels. If you need to adapt madVR to your display setup, you can do that in the madVR options, not via the 3D LUT encoding. The only option you have with regards to 3D LUT encoding is whether you’d like to pass or clip WTW.
To me the problem resides in your software and the blocked 16-235 configuration.
yCMS generates a 3dlut file which can be manually setup as an external LUT3D, like if it was generated with DisplayCAL. It’s full range and works like a charm. Same applies to collink -en -En (full range madVR lut). They can be validated with DispcalGUI and show low dE and rec709 gamut. I mean, they are working properly.
That does not apply to madVR LUT3D genetated with your software. An AdobeRGB green is an unmistakeable gamut error spotted by sight.
How can I configure madVR to work properly with your LUTs as you suggest? I mean, it’s just a computer, display port cable and Eizo CS240 monitor, LAV 0.68, madVR 0.90 and media player classic home cinema. If CS240 is removed, it’s a pretty basic & common configuration for a computer.
The only difference is that due to my monitor’s gamut, I can spot by sight large inacuracies in red & green caused by DisplayCAL LUT3D in 16-235, the fact that the most saturated boundaries of rec709 gamut (0-255) are left “color unmanaged” with such LUT3D . An user with a sRGB-like monitor it’s very unlikely that would have noticed such wrong behaviour.But that setup is NOT working, no matter if i set LAV to output limited RGB range, no matter if madVR display configuration is set to limited range: if I use DisplayCAL LUTs…. colors are wrong if near to REC709 primaries. I mean oversaturaed, not color managed at all. Other less saturated colors show properly for 16-235 lut.
yCMS or argyllCMS “-en -En” full range LUT3D works properly: rec709 primaries seen on my monitor.
So again: How can I configure madVR to work properly with your LUTs as you suggest?Maybe it’s madVR processing what is wrong, and with standard gamut (sRGB) monitor/TVs no one noticed it.
Do you have access to a widegamut monitor? Could you post here a LAV+madVR + limited range LUT3D that does not render an AdoeRGB Green when Rec709 pure green is sent to video player program in such widegamut monitor??Seems that my previous message is lost…
I found where the error was. It was a bad DVD ISO for testing sRGB/Rec709 primaries.
http://www.homecinema-fr.com/colorimetre/release/DVD_V2.0.0.ISO
With 16-235 LUTs, “Réglages avancés” menu, at the end of the gradiens an oversaturated square appears… IDNK why. Anyway, I downloaded some MP4 files samples to test Rec709 primaries and DisplayCAL LUT3D looks fine. I wonder why full range LUT3D looks good too….Could you test with a widegamut monitor if that ISO looks oversaturated in that menu with madVR 16-235 LUT?
Thanks for your time.
Florian,
could you tell me when I make a 3dlut for madvr from my current icm profile via the 3DLUT maker software from displaycal, should I have to check “apply calibration vcgt”, and should I check “disable gpu gamma ramps” in madvr when I manually install the 3dlut?when I make a 3dlut for madvr from my current icm profile via the 3DLUT maker software from displaycal, should I have to check “apply calibration vcgt”,
Yes.
should I check “disable gpu gamma ramps” in madvr
No, madVR is smart and automatically ensures the correct calibration state when a 3D LUT is used (which requires the vcgt to be applied), so this option should not be used.
The only option you have with regards to 3D LUT encoding is whether you’d like to pass or clip WTW.
Where is that option exactly? Is that what white point scaling refers to when setting the rendering intent?
Where is that option exactly? Is that what white point scaling refers to when setting the rendering intent?
On the 3D LUT tab, “Input encoding”: Either “TV RGB 16-235” or “TV RGB 16-235 (clip WTW)”.
Oh, that’s what you mean! Thank you. I automatically assumed that the other option would be RGB 0-255 and never even bothered to click on it.
So, what is the effect of this option, Florian? Does it mean that BTB and WTW are not even mapped to the display’s gamut, regardless of madVR output range? Would this make AVS HD 709 calibration patterns with BTB and WTW steps useless? Is there any benefit from that second input encoding option?
