Display Calibration

[Damien147]

I think I know the answers but just to confirm.

Can you calibrate HDR?

My colorimeter(colormunki display) is 1000 nits.If my display is higher than 1000 nits I need a new colorimeter?

[huhn]

i never tried such a think but i guess so.

[aufkrawall]

but you don't have a clue how white looks like without a Spectro meter.

Both 6500K and 6800K are "white", to throw some random numbers. It is impossible to guess what you actually intend to say, so I'll leave it there.


why even calibrate if the display is already better then your meter wow...

Of course the measurements are very likely wrong in this case, the chances that both office PC displays are gamma 2.4 with their default gamma setting are unrealistic.


d65 is kinda red.

:stupid: It is not.

[huhn]

you have 2 modern meters at and and they agree and you take the results of an old known to drift meter and say the other too are wrong seriously...

[aufkrawall]

Seriously, if you can't distinguish gamma 2.2 from 2.4, please don't reply to my posts.

[huhn]

smart...
so can i distinguish gamma 2.4 and 2.2. yes i can... i can make you even images of that but it has nothing todo with this.
but your absolute disregarded of calibration and understanding of it the issue here is now i can't see the difference between gammas because you have to point your finger at something when you have zero arguments.

you have 3 meters one telling it is gamma 2.2 and two tell you it is 2.4 and now you talk about seeing the difference i can't see your stuff and even if i do.
you don't have a clue which is correct if you just take the data
just read your own stuff:
-despite of the Spyder 4 failing miserably in detecting both white and black brightness, this really seems to be of little to no consequence for the actual calibration result in comparison to the newer colorimeters with typical gamma 2.2/2.4 curves
do you even know how gamma is measured at all?
by reading brightness which you confirm (based on what is yet another mystery) to be bad.

by using your magical gamma seeing eyes.

wow smart but can i see the difference between 2.2 and 2.4 calibrated from meter i don't have here on displays i don't have here?
no i obviously can't.

you are claiming a spider x and a i1d3 can't do a gamma ramp at all because the objectively worse meter looks better to you in a calibration thread...

[aufkrawall]

you are claiming a spider x and a i1d3 can't do a gamma ramp at all because the objectively worse meter looks better to you in a calibration thread...
No, I said this is what happens exclusively with those particular two VA panel monitors. You read what your confirmation bias wants you to read. The old Spyder 4 correctly measures gamma as 2.2 with OLED devices (no difference in this case vs. the two newer colorimeters), so don't make up even more bullsh*t you want to be true to fit your point.

[huhn]

getting a wrong gamma means your meter reads brightness wrong depending on the level.

do you know what happens when your black/white is read to high/low? this changes your effective measured gamma. you sad your spyder reads brightness for black and white wrong this literally means it is reading the gamma for these wrong. how you confirmed that i don't know. why would it do a better job at the other brightness level then the other meter sorry that's hard to understand.
yes the spyder x and i1d3 could be wrong here i have no clue how old they are but that's not my point my point is you can not properly proof that like this.
you could also show the gamma reading?

btw. feel free to read how long the life expectancy of a spyder 4 is about 3 years that's it.
i have to sadly replace my i1d3 because it could have drifted too. some people will tell you they are not like old meter that life about 3 years which is true.. that doesn't mean they will live forever or even close to.

i was not in the boat of the spyder is useless because the spyder x is a fine meter.

there are also test done compared to spectrometer:
https://www.chromapure.com/newgear_i1%20Display%20Pro%20Accuracy.asp
https://www.chromapure.com/newgear-new.asp

[aufkrawall]

getting a wrong gamma means your meter reads brightness wrong depending on the level.

do you know what happens when your black/white is read to high/low? this changes your effective measured gamma.

Doesn't make sense. The x-rite measured contrast of 1100:1 for my IPS device and reports gamma 2.2. The Spyder 4 measures 770:1 and reports gamma 2.2 too...

I suspect you are greatly exaggerating brightness measurements as a factor for pure power gamma 2.2/2.4 curves. Even BT.1886 still is similarly bright for dark shades with the x-rite/spyderx compared to spyder 4 and I dare to say hardly anybody would notice the difference in a double blind test...

[huhn]

i don't have your number.
black offset is unlikely to change it but can. it highly depends on the formula and how cleaver it ignores close to black numbers or if you did it yourself.
if you try to measure stimilus 10 % but your device can't read the difference between it and stimulus 5% you would get odd gamma values.
stimulus 10% for gamma 2.2 is 0.63 % for 2.4 it is 0.40 %.
depending on how deep your screen can go it could produce values the spyder 4 can't read and it will see a very low gamma.

white will be drastic.
for 90% stimulus the difference between gamma 2.2 and gamma 2.4 is ~1.6 % brightness(77.66% and 79.31). just assume what 5 or 10 % would do to the calculated gamma.
if the device is actually 100 nits but it reports 110 nits i leave the rest up to your math.
without accurate white you can't even calculate correct gamma numbers it's pretty much end here. even if all other stimulus are read correctly the calculated gamma is just plain wrong.
but i don't know how off your spyder reported white is by 5% 20% no clue. 1% shouldn't matter to do a gamma difference of 0.2 but i didn't calculated it.

but i will do the math for 100 nits 2.4 read as 2.2 it is:
97.9 nits that's not much...
for stimulus 90% an error of 2.1 nits stimulus 100% is a gamma difference of 0.2... assuming stimulus 90% is read correctly.

in the end you just had to compare the stimulus that it can read accurately to see where they disagree and where they agree.

and if you think i'm exaggerating the important of brightness gamma is calculated from the peak white. looks like i was heavily underestimating it feel free to check the math it's not like it do this every day.

[aufkrawall]

~0 difference in measured gamma between 81nits (as reported by Spyder 4) and 125nits:
https://abload.de/thumb/81nitsrqk7l.png (https://abload.de/image.php?img=81nitsrqk7l.png) https://abload.de/thumb/125nitst2jre.png (https://abload.de/image.php?img=125nitst2jre.png)

I could of course also verify the gamma correction on basis of Spyder 4 measurements with SpyderX validation. But do I feel like it? Nope, because result would be as "surprising" as the one above and thus waste of time.

[huhn]

sorry i need far more context.
i just see to measurements that are very similar that's all.

one is supposed to be 81 the other 125.
why would the gamma look massively different?
it also the same meter isn't it?

[aufkrawall]

Plot twist: Looks like the previous i1 DisplayPro I had access to before was just broken. Got hands on a "new" one (packaging was still sealed) and calibrations with it don't cause yellowish white tint.
Switching between VCGTs of the Spyder 4 and i1 DisplayPro with gamma 2.4 98% black output offset hardly changes the image at all. BT.1886 is a bit brighter with the Spyder 4. So, gamma behaves as expected.

However, there is another issue, which actually is a significant one: Since the Spyder 4 detects much wider native gamuts with every display vs. both the SpyderX and i1 DisplayPro (the latter the narrowest), gamut mapping results with the Spyder 4 are much more desaturated. This seems to get worse the bigger the display gamut is, which in return means gamut mapping with the Spyder 4 is completely unusable with wide gamut displays (well, but ofc still better than extremely oversaturated rec709 without any clamp at all). I've seen such results also with the Spyder 5 on the internet (e.g. for my very display, somebody on YT scores the exactly same DCI-P3 coverage with a Spyder 5 as I do with the allegedly even much older Spyder 4 unit).

When it comes to SpyderX vs. i1 DisplayPro, the latter also seems to be the much better choice due to the vast amount of spectral correction profiles for that sensor. It saved the day when calibrating a Dell G3223Q, which was impossible to calibrate with the SpyderX (factory "calibration" of its white point is a sick joke).

[Damien147]

The last time I calibrated after calibrating whitepoint I noticed that the TV dropped from the 100 nits target and had to adjust backlight again supposedly but I think I've read that you don't touch it after whitepoint and left it like that.Is it true that you leave backlight like that after whitepoint calibration or it's ok to readjust backlight to target nits?

[Damien147]

Or maybe I could calibrate backlight to 110 nits intentionally to drop by itself to the 100 nits target after whitepoint calibration.Is it a good idea?

[Damien147]

I got confused and calibrated my TV by setting the GPU to YCbCr 4:2:0.After the calibration I changed the GPU to full RGB and 0-255 for the rest of the chain.Am I fine or do I need to calibrate again for full RGB?

[huhn]

just run a verification

[Damien147]

I tried to run a verification but I didn't know how to do it and I ended calibrating again.There was something wrong with the picture and now it's better.Thanks for the answer.

[Damien147]

GPU:full RGB with Madvr and TV set at 0-255.The TV runs at 4:2:2 because I am trying to get rid of PC mode(4:4:4).Is there any problem running with this configuration by having madvr playback in mind?

[huhn]

yes it not as good but is not a problem in general.

[Damien147]

Ok,thank you.

[Damien147]

I want to create a 3dlut to calibrate my picture to bt.709,6500k and bt.1886.I opened displaycal and put the Video 3D Lut for MadVR setting.I run it with default settings and then I created a verification report with also default settings.I get this (https://ibb.co/QcfSWm5)result.Am I doing something wrong?If yes what do I need to change?

In displaycal's display & instrument tab I only chose my TV where it was saying Madvr and left correction at auto.

[Damien147]

I found the proper correction for my TV and loaded it.Now I am running the calibration again with default settings.Am I doing it right?


edit: Again these (https://ibb.co/Ns7DdHq)''not ok'' results.What do they mean?What do I have to do?

[huhn]

o wow...

there are multiply reasons this could happen one would be vivid mode.
the device is simply not stable so it can not be calibrated as it is now.

or you are just not verifying the new 3d lut where 3d LUT is simply not loaded.
if that's the case you should really fix your white point before calibration.

edit: btw. the KU6300 can't do 23p at all(it will accept it but will do a 3:2 which is liberally the same as send 60 in the first place). if you want 23p as the creator intents 60 +SM is the best you can do on this TV.

[Damien147]

I returned to PC mode and there I have standard and dynamic mode,I have the TV at standard mode.I have calibrated 2 point grayscale and set whitepoint to warm 2 which is supposedly closest to 6500k.Then I run the 3dlut for Madvr and when the 3dlut was created I cancelled the installation.I do it like that and move the 3dlut only to a folder in madvr,then I load it in madvr.I suppose I did it right but did wrong the verification.I also asked in displaycal forum and got this answer:
You are not validating with LUT3D applied. You are validating if your display without profile VCGT calibration, only with OSD settings yiu changed, matches Rec709Â… and it does not, which is expected.

You need to apply LUT3D and measure pacthes in madVR TPG like in HCFR tool, or you can validate in DisplayCAL with ICC equivalent of a LUT3D (device link).

I can't understand sh*t.


If I did the procedure fine as it seems I don't care how to properly verify the 3dlut because if I understand well there's not much I can do.Am I right?

About the 23p you said I tried to experiment these days but I returned to 60 +SM as I was now.

[huhn]

hm
https://abload.de/img/3dlutt5i17.png

well i don't know i mean a delta of over 4 for white point should not be there if you calibrated it before may it is the correction and the old calibration is for no correction so it has to be redone?
or it may not find it.

sorry i don't use a 3D LUT currently my OLED is not stable enough to get a calibration through.

[Damien147]

I don't know what else to do if I did the procedure right beyond my mistake with the verification.In pc mode I have only 2 point White Balance,10 point is disabled.My settings and what I did with the 3dlut for madvr if I want my TV calibrated to bt.709,6500K and bt.1886 are right supposedly,correct?

[huhn]

do you have a tint option?

[Damien147]

No,it's grayed out in PC mode.The most accurate picture mode is the movie mode on my TV from reading reviews around but I have to deal with standard mode because of PC mode.I have option only for standard and dynamic mode.As it seems standard mode is not that accurate but that's the only option I have and have to deal with that as I said.Supposedly a 3dlut for madvr fixes these inaccuracies and lack of some options because they are greyed out.

To conclude I want my TV calibrated to bt709,6500k with bt.1886(for Madvr only) in PC mode where I am forced to use the not so accurate standard mode with the limited options.

I've set the TV to warm 2 which is the closest to 6500k and adjusted backlight to 100 nits.Then I've calibrated 2 point and moved to displaycal for the 3dlut.

I chose Video 3dlut for Madvr in displaycal settings and loaded the correction for my TV.Then I run it with default settings and when the 3dlut finished I chose cancel.

I moved the 3dlut only that was made in a Madvr folder and loaded it in Madvr.

Is the procedure I did correct?

[Damien147]

In displaycal forum they told me to use the device link profile in the verification tab.I just ticked it and run it as it has a LUT3D equivalent “device link” ICC file.These (https://ibb.co/St42GFK)are the results and everything seems good!!!!

Thank you very much huhn for helping me out.

[Siso]

@chros what black output offset should I use with a monitor with 902:1 contrast, and black level 0.1116 cd/m²? The gamma will be 2.4 relative or absolute? I wrote in the SDR Display EOTF (Gamma 2.2/2.4 or BT.1886) tread but no one replied me.

[Damien147]

By adjusting TV's backlight and creating a 3dlut for Madvr is all you need to have a calibrated picture,am I right?

[Damien147]

When I calibrate I create a 3dlut for madvr for my TV but for my monitor I just use an icc profile that I created for general usage.Am I losing something picture quality wise compared to a 3dlut by using an icc profile with madvr for my monitor?

[huhn]

yes.
a 3D LUT is created an icc and the is a good reason this takes minutes.
for an icc file it now has less than an ms.

you are also not defining a target gamma and such in the same way.

[Damien147]

Ok,next time I will create a 3dlut for my monitor too.Thank you.

[Damien147]

I have a maybe silly question but I wanna make sure.
I calibrate once a year as I know as recommended and now it's been almost a year since calibrating my monitor and TV.I am thinking about skipping calibration this time because I am lazy and calibrate next year again.
My question is does picture calibration drift by usage or by time?I mean my TV was off for almost 6 months and I was using my monitor only for 1-2 hours daily during the summer.Does it matter?
Can I get away without calibrating this time and do it again in a year if I am not missing much?Or I am missing?Just for movies with Madvr,no photo work or whatever.
Picture looks fine to me.

[huhn]

just run a vertification.
depends on the hardware and they usual age by use.

[Damien147]

Of course I can run a verification but if I put myself in the procedure to move my TV and blah blah blah I will end up calibrating the TV.
If they age by usage usually it means that calibration drifts with usage usually and by having in mind that TV was off for almost 6 months I think I can get away with it as a conclusion.
I mean TV is calibrated for almost a year but because it was off for the half time it probably means that calibration drifted less.It's just for movies.
I created the 3dlut for my monitor in August with my previous question by the way.

Thank you very much huhn,you are always very helpful.