- This topic has 35 replies, 2 voices, and was last updated 3 years, 5 months ago by
.
-
Posts
-
Sorry for the basic question but is it possible to just take a reading of a monitors current white point. I feel like my monitor is leaning in a certain direction (whites feel a bit too warm) and I’d like to be able to just take a reading of the temperature that whites are currently being displayed first without doing a full calibration.
It could well be that doesn’t even make sense. My knowledge is amateur at best so if anyone does have an answer, please explain in ‘amateur terms’
I was wondering if the attached is enough to answer my question.
Ok so I’m mostly interested in the sRGB option in the OSD of my monitor so here’s what I’ve done.
- Reset Monitor to Factory Settings
- Set OSD to sRGB
- Installed DisplayCal
- Connected i1 Display Pro
- Configured Display Cal with the relevant correction for my display (I think)
- Set Whitepoint to Chromaticity Coordinates (0.3127, 0.3290), White Level ‘As Measured’, Tone Curve Gamma 2.2
- Clicked ‘Calibrate and Profile’
- Placed i1 onto the screen
- Clicked ‘Start Measurement’
- I then noted down the current coordinates without adjusting anything (my monitor doesn’t let me adjust anything anyway – Dell Up2716D)
- Plotted those coordinates into GoCIE (Pink X)
If what I’ve done above is correct, am I right in assuming the current ‘white’ I’m seeing, is leaning towards the greens rather than what I’d call ‘True White’
If someone could clarify that would be much appreciated.
As I say I’m a complete novice, so go easy, but I do trust my eyes and I’m convinced that the white’s on my screen aren’t how I belive they should be and are displaying with a colour cast.
My main goal is to make sure I’m seeing true white, as in white white, not warm white, not cool white.
Calibrite Display Pro HL on Amazon
Disclosure: As an Amazon Associate I earn from qualifying purchases.UP2716D is a WLED PFS variant (AdobeRGB+P3) with higher “noise floor” on red channel that WLED PFS reference in DisplayCAL (HP z24x).
There are user made corrections for UP25/UP27, just make sure that they are 3nm resolution, CCSS type, and that when you plot them in displaycal red does not beem to be a linear combination of the 3 channels (sRGB/AdobeRGB emulated red):colorimetercorrections.displaycal.net
Latest version DUCCS for UP25/27 is supposed to use a simpler variant (WLED PFS P3 95%, not actual backlight) so you can make a HW calibration to sRGB gamma 2.2 (custom xy mode in DUCCS, set sRGB coordinates then 2.2 gamma). White should be “white”. if it is not “white” you can apply a GPU calibration with displayCAL on top of that CALx, white will be corrected on GPU since OSD RGB gains are locked.
Use a custom native gamut 3nm CCSS correction for colorimeter in DisplayCAL.
Hi Vincent
I was hoping you’d appear in the replies so thanks for that. However, as I said I’m a novice so please bear with me.
If I understand correctly, DisplayCAL will not allow me to calibrate to sRGB and store in the User (CAL1 CAL2) slots, so I’m forced to use DUCCS.
From previous experience DUCCS is horrible to use, so what would be the benefit of me calibrating using DUCCS at HW level compared to calibrating using DisplayCAL at GPU/OS/SYSTEM level?
Again please forgive my very basic understanding of things. I have just bought a PD2720U – I was hoping to use this as my main monitor and the UP2716D as a second monitor to use for reference images. My main line of work is CGI for property. We usually find a nice reference photo that we’d like to imitate (lighting, colours etc) in the CGI. However, after turning them both on and placing them side by side, the whitepoints were vastly different so this exercise seemed utterly pointless.
Also for clarity I use the terms GPU, OS and SYSTEM interchangably so please correct me if that’s wrong
From previous experience DUCCS is horrible to use, so what would be the benefit of me calibrating using DUCCS at HW level compared to calibrating using DisplayCAL at GPU/OS/SYSTEM level?
DisplayCAL only corrects grey, no gamut emulation (sRGB).
But, you can select Custom color OSD mode, use HCFR (Displaycal “cousin”) and with spot colors use saturation 6 axis RGBCMY controls to simulate RGB primaries to be close to Rec709.
Once RGB primaries (simulated inside monitor) are sRGB like, move to DisplayCAL and calibrate as usual with full RGB gain control to fix white (you can fix white in HFCR too).
Import/use the same CCSS 3nm fro native gamut in HCFR too.Again please forgive my very basic understanding of things. I have just bought a PD2720U – I was hoping to use this as my main monitor and the UP2716D as a second monitor to use for reference images. My main line of work is CGI for property. We usually find a nice reference photo that we’d like to imitate (lighting, colours etc) in the CGI. However, after turning them both on and placing them side by side, the whitepoints were vastly different so this exercise seemed utterly pointless.
Equal or worse than Dell UP. No HW cal at all, no SDK.
If you wish a good sRGB monitor (your work points to that IMHO) you can choose other sRGB like PD from Benq, not that one (widegamut). Even a NEC EA 27″ UHD (sRGB like) at the same price.Regarding white point match you’ll need very accurate spectral corrections to get a visual match by matching color coordinates, otherwise they won’t match because color coordinates read are not real. Also there is a small chance of observer metameric failure (you and standard observer do not match), so even with a perfect device visually they mat not match TO YOU.
It’s easier to match them numerically “with a good correction” and then match the visually worst by visual approach (DisplayCAL has a visual witepoint editor to do this)Also you’ll have the same issues with PD. It’s a widegamut with an unknown backlight to me. Maybe “photo” WLED PFS (HP Z24x), maybe one of those low quality QLEDs from AUO that Benq uses in other low quality monitors (SW line)… Unless you use proper correction white may look not white because colorimeter readings are wrong.
Look in colorimeter database correction. Same warnings, you want CCSS + native gamut (no simulated primaries) + 3nm or better.BTW, check PD manual. If sRGB mode is locked (typical) you can try to simulate sRGB in the same way as Dell UP, check if there are manual saturation controls, try to get RGB primaries to sRGB/Rec709 on HCFR.
You’ll need to find proper spectral correction for that widegamut PD. If you have no luck finding one, try WLED PFS AdobeRGB+P3 (HP z24x) if not visually white try one from SW2700PT. SInce it’s guessing it’s not sure you’ll get good results .You’re right. Wide gamut is not necessary for me …. Currently. The main piece of software I use is 3DS Max, which isn’t colour managed. This is the only software I use that isn’t colour managed. Frustrating.
But … The biggest problem is I Think it soon will be in the next few releases. So if I’m going to spend significant money on a monitor would it not be better to make sure it’s future proofed?
If not, assuming budget wasn’t so much an issue, which monitor would you suggest?
I can.probably stretch between £1500 and £2000 on a monitor but at that cost I need to make sure it’s perfect. The BenQ is going back. Admittedly I was drawn in by the marketing. I’ve now got my eye on the CS2740 but it’s wide gamut if I remember rightly? 27 is the minimum size requirement, the images I work with are often 6k pixels and above.
I’d love to buy a monitor that’s perfect and won’t need replacing in a few years time.
This has always been an annoyance of mine and to date I’ve just accepted things and learnt to compensate for any inaccuracies but I’d love for that to change. I also appreciate I can’t control the viewing environment of the client and most likely they’re viewing on out if the box phones and Mac screens (creative agencies) but as long as I know that what I’m seeing is as intended then thats fine by me. But of course I need to do that in the correct conditions at my end. No point in me making a white ‘look’ white on my screen if if the reality is I’ve compensated for a dodgy colour cast on the screen I’m using. That would just make matters worse on a correct screen right? Say I’ve compensated for a green cast on my screen, it would look more pink on a correct screen. Or am I misunderstanding?
Also something that would improve my knowledge of calibration and monitors quite significantly. If I calibrate a monitor it’s default state (say Standard/Native) on a wide gamut monitor with no onboard LUT Storage. What happens if I then change the OSD to sRGB after calibration?
What would change beyond the colour gamut that the monitor will then display?
I’m trying to figure out what characteristic of a display are stored where?
What information do the OSD modes contain? For example, assuming I was happy with whites looking white after calibrating to native gamut, would the whites remain and just the colour gets limited if I change to the OSD to sRGB mode?
I’ve now got my eye on the CS2740 but it’s wide gamut if I remember rightly?
Yes. good model, just 200-300 euro more than bad quality models from BenqSW
This has always been an annoyance of mine and to date I’ve just accepted things and learnt to compensate for any inaccuracies but I’d love for that to change. I also appreciate I can’t control the viewing environment of the client and most likely they’re viewing on out if the box phones and Mac screens (creative agencies) but as long as I know that what I’m seeing is as intended then thats fine by me. But of course I need to do that in the correct conditions at my end. No point in me making a white ‘look’ white on my screen if if the reality is I’ve compensated for a dodgy colour cast on the screen I’m using. That would just make matters worse on a correct screen right? Say I’ve compensated for a green cast on my screen, it would look more pink on a correct screen. Or am I misunderstanding?
Just put your screen to your desired target. Only if all customers used the same alt calibration target (like a mobile app testing against typical whitepoint of iPads) it will make sense to use that target
Also something that would improve my knowledge of calibration and monitors quite significantly. If I calibrate a monitor it’s default state (say Standard/Native) on a wide gamut monitor with no onboard LUT Storage. What happens if I then change the OSD to sRGB after calibration?
What would change beyond the colour gamut that the monitor will then display?
I’m trying to figure out what characteristic of a display are stored where?
What information do the OSD modes contain? For example, assuming I was happy with whites looking white after calibrating to native gamut, would the whites remain and just the colour gets limited if I change to the OSD to sRGB mode?
Whatever vendor wants, so since you cannot know if you change some OSD parameter => recalibrate, full recalibration of grayscale in DisplayCAL and a separate/spefici profile for that new setting.
Typical gamut emulation is made through a prelut-matrix-prelut. Prelut 1D LUT undo gamma encoding to linear. matrix mixes channels (now linear encoded) to emulate less saturated primaries, postlut re-encode gamma. Grey & white can be stored in one of these luts, like postlut. These 1D Luts are like GPU LUTs,
3 x 1024 entry x 12-16bit preLUT,
3 x 3 x 12-16 bit matrix for gamut emulation,
3 x 1024 entry x 12-16bit postLUT,
There are other more complex alternatives like a LUT3D, but typical low cost low quality widegamuts and even good quality widegamuts (CS) use this appoach.Ok there are a few things I think I’m missing basic knowledge of here.
It’s so difficult to ask questions when I don’t really know the correct way to ask it, however.
When you say “Recalibrate Grayscale” is this fixing the whites?
Do all the different display modes have different ‘whites’.
Life would be much easier if the different display modes weren’t ‘locked’ and you could just calibrate over the top of them, assuming the primaries were correct in the sRGB mode, it would just be as simple as setting to that mode and fixing the whites, right? Because these modes are locked, I either have to do it manually as you’ve described or use DUCCS to store to the onboard LUT. Am I right in thinking that anything other than these two methods would result in the Wide Gamut issues I seem to be having and colour casts in the whites?
Are you able to elaborate on this sentence – “Whatever vendor wants, so since you cannot know if you change some OSD parameter => recalibrate, full recalibration of grayscale in DisplayCAL and a separate/spefici profile for that new setting.” that last bit confuses me a little.
Again you have to bear with me, it’s my first genuine attempt at trying to understand this stuff.
I’ve also just installed HCFR – it seems I need to spend time reading a manual for it.
I also don’t understand this sentence fully nor how to execute this in HCFR
“Import/use the same CCSS 3nm fro native gamut in HCFR too.”
Ok there are a few things I think I’m missing basic knowledge of here.
It’s so difficult to ask questions when I don’t really know the correct way to ask it, however.
When you say “Recalibrate Grayscale” is this fixing the whites?
If OSD is locked for RGB gains like in CAL1/CAL2 modes, yes. Whit eis another grey. White correction wil be the values at 255 input in GPU LUT.
It may cause banding on some gPUs.Are you able to elaborate on this sentence – “Whatever vendor wants, so since you cannot know if you change some OSD parameter => recalibrate, full recalibration of grayscale in DisplayCAL and a separate/spefici profile for that new setting.” that last bit confuses me a little.
You do not know what electronics are used. I put an example of a common prelut-matrix-postlut.
If you change someting in contrast, gains or internal LUTs, you’ll need a new profile. If you wish to correct greyscale (including white) by GPU calibration on top of an OSD mode (Standard/Cal1/CAL2…) you’ll need a new profile for each OSD mode.
I’ve also just installed HCFR – it seems I need to spend time reading a manual for it.
Dell UP > Custom color mode, set gains to 100, Set brightness to a reasonable value, set contrast to factory defualt if you modify it.
Go to custom color > saturation. yu’ll have 6 axis controls, RGBCMY.
Choose on HCFR proper spectral correction for your Dell.
Choose rec709 as target (it should be this way by default, you may want to change target gamma)
Measure 255 reg, green, blue… etc. There is a icon button to that. Red & green will be off from sRGB ones… it’s a widegamut. Use 6axis controls to get Rec709’s ones lowring saturation, measure again, lower them, measure again..I also don’t understand this sentence fully nor how to execute this in HCFR
“Import/use the same CCSS 3nm fro native gamut in HCFR too.”
There should be an ArgyllCMS folder in your own user AppLocal or Roaming folder on windows. Check that the comunity made CCSS ypu are going to use is there. It should. If not copy it from where you downloaded it
