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Hi, I just ran my first calibration, results look great but am I right in assuming my white point is off?
The verification report seems to come back OK. but the profile clearly shows the white point is off mark.
I left all of the settings on default before the calibration, however I added a correction that was recommended in another post.
It seems that you did not set a target whitepoint, so it looks like DisplayCAL aimed to closest daylight nativewhite. That is “user error”.
Also there is no “mark” for calibration target. Mark in screenshot is sRGB whitepoint because you chose to compare your display profile to sRGB colorspace. If you choose a profile with D50 white it will be further from a perfectly calibrated & profiled display to D65.
Grey range is not very good, use slow calibration speed. Some greys are a litle pink others are a little green. It is usually solved or improved with slow speed (=more calibration patches, not more profiling patches, just more calibration patches).
Contrast is low for a native whitepoint IPS display. Since its a Dell UP it looks like you enabled uniformity compensation. Did you? AFAIK if you do that, which may be a very reasonable thing to do if default uniformity is bad and you plan to use it for photo, UP models lock RGB controls for white point. If you whish D65 white, like sRGB or AdobeRGB, in that display in that configuration then it needs to be corrected in GPU like greys, loosing a litle contrast. If that is your situation, don’t worry if RGB controls are locked and you cannot get color bars to the center in interactive display adjustment, DisplayCAL will correct the remaining distance with GPU calibration.
Hey Vincent, thanks for the quick response, that’s very helpful! I should clarify I’m using this monitor for video color grading.
I will run the calibration with a set white point (D65) and a slower calibration speed and see what comes out.
Yes, uniformity compensation is enabled (though the uniformity isn’t exactly terrible when its off, I’ve seen worse) but how would I go about using GPU calibration? I assume that would be done in the Nvidia Control Panel… There are options for Adjust Desktop Color Settings and Adjust Video Color Settings where the RGB gain can be adjusted.
Thanks again!
DisplayCAL, i1Profiler and all these programs that cannot write internal LUTs to monitors use “GPU calibration”.
There are 3 dedicated tables with 1DLUT in GPUs to fix grey ramp (one per channel, per output). Those tables are stored in VCGT tag in ICC profiles for displays. ICC profiles produced with HW cal tools like ColorNavigator for Eizos store a linear lut, so there is no modification in the output.White point is just the brightest of greys, so it can be corrected in such 1DLUT. If you correct whitepoint in GPU, white 255 input will not have a [255,255,255] output, it will be lower in 1 or 2 channels to fix whitepoint. That means to loose a little contrast if white is close, and more contrast if native white if far from native white.
So no need to change GPU control panel, DisplayCAL will do its stuff and store white point correction in 1DLUT.
That can be useful for sRGB preset in your monitor as expained in th other thread.If you are going to use Custom color preset with uniformity=ON to make a LUT3D for Resolve, you just need to profile display without correcting grey or white, just measuring how it behaves in an accurate way. When you make a LUT3D from Rec709 to that profile, issues in your display should be corrected. That is what a LUT3D is: input colorspace RGB coordinates in (like in Rec709) => output colorspace RGB coordinates out (like in your display)
But if you wish to use full native gamut @ D65 for Photoshop or other uses with color management then you can do as expained in previous message: calibrate to D65 in GPU (Photoshop & others), then use that profile as input for making LUT3D. GPU calibration will be carried to LUT3D if you check VCGT stuff in DisplayCAL LUT3D maker.Note: GPU calibration depends on:
-GPU LUT having more than 8bit per entry and some kind of dithering, otherwise banding is expected (but it may be more or less noticeable). Nvidia does not help here in some models, same for intel iGPUs.
-an application able to use full GPU LUT capabilities without truncation of LUT contenst to lower bitdepth, like DisplayCAL tray for Windows.
-how bad is display behavior uncalibrated. The worse it is, like severe green to pink tints in grey ramp, the more patches should be used in calibration stage (controled by “speed” slider in Calibration tab, maybe you need to enable advanced options)Thanks for the explanation Vincent, I’m sort of new to calibration so forgive me if I don’t fully follow along – but your explanations are extremely helpful.
You are correct in saying that color uniformity can ONLY be used in the monitor’s “Standard” presets, as soon as a Color Space or Custom Color is selected it turns off.
So when I get to the measurement step in DisplayCal, your saying I should just skip it? and DisplayCal will make up for it in the profile?
After I’m finished with the calibration I can then generate a 3DLUT in the LUT Maker and follow the wiki directions to use it in the Resolve Color Monitor? No reference monitor here at the moment, Desktop only.
Once again, thank you!
You are correct in saying that color uniformity can ONLY be used in the monitor’s “Standard” presets, as soon as a Color Space or Custom Color is selected it turns off.
CAL1 and CAL2 (HW cal modes) have no uniformity correction (UC), but Custom color should be able to use it. RGB controls will be locked of you enable UC in custom color, but you should be able to raise or lower brightness. All previous U and UP models with UC were able to use UC in custom color mode (although different generations locked different OSD controls with UC=ON)… so it’s weird that you cannot enable it.
Move to Custom color, then enable UC and you should be able to rise brightness but RGB gains shoudl be locked.anyway:
So when I get to the measurement step in DisplayCal, your saying I should just skip it? and DisplayCal will make up for it in the profile?
Whatever whitepoint you did not correct in interactive display will be corrected in GPU grey calibration IF you set a whitepoint target… and it looks lik you did not in your 1st post.
After I’m finished with the calibration I can then generate a 3DLUT in the LUT Maker and follow the wiki directions to use it in the Resolve Color Monitor? No reference monitor here at the moment, Desktop only.
There are two ways:
-wiki recomendations meant for Resolve
-make a D65 desktop profile for other uses, then make LUT3D with that profile. I could be more prone to user errors/missconfigurations.Hi Vincent, so I ran two calibrations and included the reports.
Both calibrations with run with the same settings with minor differences. Both target D65 white point which was successful
report 1: no measurement, only profiling
report 2: measured white point by adjusting monitor’s RGB gain and overall brightness. So no screen uniformity.
What do you think?
Native white is close to D65 so you loose just a few unique grey levels, you keep about 94%. Ok.
Grey range is not good in calibration, huge a* oscillations in grey for the two… but these issues are captured in profile info so LUT3D for Resolve may be able to fix it.
If a display has that kind of issues I’ll go for slowest calibration speed, full 12->24->48->96 iterations of ArgyllCMS. It’s about 30-40min in calibration stage with an i1displaypro and a 1000-1200:1 screen. In a low contrast display should be a little faster.
It may not be needed for Resolve, as I said grey issues are captured accurately in profile TRC info as reports show, but I can cause troubles with color managed apps that like better behaved display profiles (you may see banding and truncation errors in almost every gradient in color managed apps and color tints in non color managed apps).CS2420 (24″ 1920×1200) should be about the same price if you can/wish to return the UP27. Other low cost brand will show the same kind or even worse issues like Benq SWs (and worse HW calibration solutions by far).
Another alternative would be an sRGB display. Viewsonic has sRGB models with HW cal for grey (same kind of software as Dell) under 500euro and should be able to reepresent full or 99% Rec709. sRGB display are less prone to show color tints in screen like the green-pink tints so common in low cost widegamuts.Just giving you options if you cannot get what you desire from that display… but first of all try to make LUT3D for Resolve (your profile TRC info is accurate so it could be corrected) and test a video B&W gradient to spot banding or pink-green isuses in grey. AVSforums should have a few examples in some thread
Calibrite Display Pro HL on Amazon
Disclosure: As an Amazon Associate I earn from qualifying purchases.Thanks Vincent, definitely will consider an Eizo for my next screen, I hear they are the best way to go.
For now this will do.
One last question, will the 3D LUT for resolve also account for white point if it isnt profiled at D65? So if I were to use my first report that I thought was off, will Resolve correct it?
One last question, will the 3D LUT for resolve also account for white point if it isnt profiled at D65? So if I were to use my first report that I thought was off, will Resolve correct it?
Open LUT3D maker. Relative /perceptual intents do not modify WP. Absolute colorimetric intents should do it (I think it’s default). Check doc for full options descriptions.
Also remember to do not choose rec1886 with a 600:1 screen (or 1000:1, or 1300:1). Try to use 2.4 (like “other”, “2.4”, “relative”, but check doc)
Do you have any recommendations for ViewSonics?
Just look for sRGB models because widegamuts will the the same as your dell. I do not remember model name but they should have a VX/VP series model, sRGB-like (so it can be used in non color managed as a common monitor), IPS 1000:1, and HW (Internal) calibration with another i1Profiler clone called “Colorbration” (like Dell’s DUCCS). It should work with retail i1DisplayPro.
I remember to see a review in “prad.de” , 27″ QHD or UHD, sRGB-like.
Great, I’ll do that. Just want to give my thanks again. You really helped me better understand this.
Hey Vincent, real quick, hows this monitor? https://www.viewsonic.com/eu/products/lcd/VP2768.php
Do you think I’ll achieve more accuracy with this as compared to my Dell?
Hey Vincent, real quick, hows this monitor? https://www.viewsonic.com/eu/products/lcd/VP2768.php
That was one of the models I saw. sRGB, HW Cal (but as all monitors can be profiles with DIsplayCAL, and even make minor tweaks to grayscale)
Do you think I’ll achieve more accuracy with this as compared to my Dell?
It has more chances to have good color uniformity than yours as most sRGB-like displays.
Search review and download monitor manual, IDNK if it supports 24p or 50i/60i inputs (same for your Dell) over HDMI, IDNK if you need those features.IDNK why you get that kind of bad grey range withthe UP and DisplayCAL. I’ve seen Dells (previous gen to yours) with severe grey tints (green pink) uncalibrated but IN SLOW SPEED (12->24->48->96 patches) DisplayCAL was able to make gray scale visually neutral and with an acceptable grey range in a*b* . But I saw it connected to an AMD card that has high bidepth in luts and dithering… that helps in visual evaluation, but DisplayCAL report should show good grey range even if GPU banding is present (banding caused by calibration needs visual check).
Try a simple matrix profile (low number of profilling patches) and slow calibration speed (up to 96 patches in grey ramp while calibratind). Then run profile validation. Check a* oscillations in grey ramp in report, right side has measurements (left is reference values). It should get better greyramp… if not, IDNK what is happening to that dell.
Also IDNK if you can see visually the grey ramp issues that repot shows. Go to google, “lagom gradient”, save PNG and open it in MS paint (no color management). Callibration issues in grey should be visible in that test in MS Paint.
