- This topic has 10 replies, 3 voices, and was last updated 4 years, 1 month ago by
.
-
Posts
-
Hi, I’ve previously used displaycal software but I was wondering: when I calibrate my screen with it I’ll get a color profile suited for my screen, but the calibration profile works in which color space exactly?
If I do not have presets on my monitor as “srgb” “Adobe RGB” or “dcip3” but the panel can display 100% for each one, can I calibrate the panel to show one of these color spaces?
If I do not have presets on my monitor as “srgb” “Adobe RGB” or “dcip3” but the panel can display 100% for each one, can I calibrate the panel to show one of these color spaces?
You can use DisplayCAL, i1Profiler, basiccolor… etc in a monitor without HW calibration to fix white point, grey neutrality and gamma (TRC) using GPU. I mean… you can correct greys, not gamut using “generic GPU calibration”. These programs compute a calibration 1DLUT that gets loaded into GPU dedicated HW for this task (and such 1DLUT is stored in display profile).
Although some GPUs have dedicated HW for gamut emulation, not just greys, AFAIK there is no common/universal way to use it in a vendor agnostic way. It would be very cool, but AFAIK no GPU calibration solution uses it (maybe some widegamut laptops with a vendor tool relying on factory calibration use it).What you can do is to use some software with LUT3D support for gamut emulation, like madVR, Resolve (and maybe reshade but I have not used it). DisplayCAL allows you to compute such LUT3D form whatever colorspace (P3) to your display colorspace (defined by your display profile).
Or if you use windows and have an AMD GPU, try sRGB to EDID gamut emulation (GPU gamut emulation), then calibrate with DisplayCAL grey ramp. Gamut boundaries in that sRGB emulation are computed from EDID data so they may not be accurate… although it would be better that native gamut if you need sRGB/Rec709 screen for using non color managed apps.So basically can I achieve the same results as in a monitor with with the same panel of mine but with embedded profiles for each color space? Or the GPU driven profiles are somewhat worse than native display embedded profiles management?
Displays do not have profiles. They CAN have some kind of gamut emulation (lut-matrix, LUT3D) to limit their colorspace to sRGB of other colorspaces.
That gamut emulation can be offered as factory calibration, user programable calibration or both.GPU calibration profiles like the ones from DisplayCAL fixes grey in a system global way (unless calibration is reset in GPU), just that, GREY (and white point too as grey 255/256). It is global because it does not depend on each app or OS support to color management.
If you have a widegamut display that covers both AdobeRGB and P3 but it DOES NOT have gamut emulation feature (factory or user made), you cannot get that display to work with a colorspace reduced/limited to sRGB/P3/etc at system level using the usual GPU calibration provided by DisplayCAL/i1Profiler/etc.
But you can:
-use color managed apps which understand ICC profiles (GIMP, Photoshop,…)
-use apps that allow software LUT3Ds (madVR, resolve,…)
-use some vendor specific feature for gamut emulation using GPU.Last one is the one that looks like a feature some new widegamut laptops have.
It is the “sRGB gamut emulation from EDID data” feature in AMDs too, and this one is system global like DisplayCAL grey calibration, limited to sRGB, limited to assumed accurate EDID data. It is under the misleading name “color temperature” (=OFF) in driver configuration for Windows.So if you have a widegamut display without gamut emulation feature, first check
-if your display is a laptop, check if it has that kind of vendor specific feature
-if your display is a desktop display, check if you have an AMD and you use windows. Then check (measure with a colorimeter/spectro) if gamut boundaries with sRGB emulation on GPU active are OK. I mean check color coordinates of emulated R, G &B against sRGB. If they are somehow “OK” for you, use DisplayCAL to fix greys like in other display and you have it.
AFAIK this sRGB emulation form EDID feature is not available in nvidia/intel Windows driver as an “user selectable feature in UI”, but underliying HW (lut-matrix-lut) should exist from them too.Maybe there is some linux distro with that GPU colorspace emulation feaure at system level, exposed to whole desktop, but if it exists I do not know about it. If such distro exists it would be cool.
Thank you Vincent for your deep explanation. I’m still getting used to some new terms.
We’re talking about a desktop PC (i’ve also got a pantone validate screen on my laptop but I run a NVIDIA and i cannot find any EDID feature)
So about the PC the screen i’ve got is a Monoprice 27″ Vivid Monitor – it has a LG LM270WR4 panel – the same panel as the Benq PD2720U.
The Benq is a certified and calibrated monitor, it has alot of switchable presets (argb, srgb, dci p3, etc)
The Monoprice has only common presents as movie-game-srgb etc etc – but of course I can tweak with colors and other parameters.
Since the Monoprice screen costs about the half of the Benq, I’m thinking to go with it, but I’m worried I cannot get the same results in color management.
Do you think losing the calibrated presets would be a bigger handicap?
I enjoy an extended color space – i’m not too much intrested in adobe rgb performance (i’ll be developing some pictures in adobe space, but not exclusively) but I’m pretty intrested in switching permanently from sRGB to DCI-P3 as it’s mostly an extension of its range and I work alot with graphic design and colors. We can say I’m looking for a similar gamut and visual performance as a Mac 2017 screen.
So realistically I would not be intrested in having too much presets to switch between but at least I want to gain the best gamut possibile overall. What do you think?
[…]So about the PC the screen i’ve got is a Monoprice 27″ Vivid Monitor – it has a LG LM270WR4 panel – the same panel as the Benq PD2720U.
The Benq is a certified and calibrated monitor, it has alot of switchable presets (argb, srgb, dci p3, etc)
Those “certification” are pretty useless. Unless you validate it with your measurement device (and appropiate correction if needed)… just advertisement.
Same goes for factory calibration, its requirements & contraints are so low that it means nothing and the “paper” they bundle with those low cost widegamut usually measures not relevant data (with the exception of RGBCMY primaries & secondaries for gamut emulation modes).
For example, let’s say it has Technicolor certifcation. ¿Do you know what it is? Constraints are mostly useless. Same goes for “paper” grayscale tracking based on Correlated Color Temperature (CCT) in kelvins. 6500K CCT is not a color, is a set of infinite colors, one of them is D65 (sRGB/AdobeRGB white) and the others are pinkish or greenish.The Monoprice has only common presents as movie-game-srgb etc etc – but of course I can tweak with colors and other parameters.
Since the Monoprice screen costs about the half of the Benq, I’m thinking to go with it, but I’m worried I cannot get the same results in color management.
It’s actually the opposite, as long as content in those color managed apps falls into that sRGB-like monitor gamut.
Do you think losing the calibrated presets would be a bigger handicap?
Which monitor? The widegamut? For color managed apps you can use full native gamut. As explained before in those color managed apps as long as content is sRGB-like and the two monitors have been individually profiled…they should match although you may need some visual white point match between them.
If you do not own or have at your disposal a measurement device you should not have bought a widegamut. If your widegamut is an AdobeRGB Benq widegamut it is likely to have some kind of HW calibration, although Benq software is one of the worst out there, so if you do not own a measurement device my recomendation is an i1displaypro. Colormunkis display or i1display studios won’t work with Benq HW cal software (same applies for Eizo, NEC, Dell…). If you want HW cal and an i1d3 colorimeter you should get the “pro”.
I enjoy an extended color space – i’m not too much intrested in adobe rgb performance (i’ll be developing some pictures in adobe space, but not exclusively) but I’m pretty intrested in switching permanently from sRGB to DCI-P3 as it’s mostly an extension of its range and I work alot with graphic design and colors. We can say I’m looking for a similar gamut and visual performance as a Mac 2017 screen.
If you use color managed apps, use full native gamut always, no need to change OSD modes. Also always tag (embed profiles, like sRGB.icm) in your image deliverables.
MacOS desktop is (poorly) color managed, so Safari webs should look like Firefox web once you enable Firefox full color mamagement (some banding may appear).If you do/can not use color managed apps in that widegamut, like some video editors then you are forced to switch to one of those limited gamut OSD modes to work with them. Again, if it is an AdobeRGB-like Benq widegamut, it may have some kind of HW calibration, so buy an i1displaypro and calibrate with is poor software* a CAL1…CAL3 slot with typical video content colorspace: Rec709 gamut, D65 white, 2.4 gamma (or 2.2). Just an example.
So realistically I would not be intrested in having too much presets to switch between but at least I want to gain the best gamut possibile overall. What do you think?
Native gamut => profile display, use color managed apps.
No color managed apps => Limit gamut to content colorspace via preset or better use that Benq HW cal and an i1displayPro.
*) Benq HW cal software never cared about accuracy with i1d3 family of colorimeters. It uses a spectral correction which is not suitable for any of benq widegamut screens. For QLED ones you can use Florian cooked native CCSS (recent threads, take a look), for WLED PFS AdobeRGB you can use DisplayCAL bundled corrections for i1d3 family, for GB-LEDs same (U2413 correction), for those P3-like Benq screens without HW cal like EW series use WLED PFS 95% P3 correction (Panasonic VVX or somethong like that).
Also you may get some warning about “profile whitepoint” vs “measured whiteppoint” in ICC v2 profiles made with that software because that software’s fault, it is not a problem your common usage (GIMP, Photoshop,etc) but do not use that ICC profiles as LUT3D making input with absolute intents.Calibrite Display Pro HL on Amazon
Disclosure: As an Amazon Associate I earn from qualifying purchases.Thanks again, I’m thinking I’m starting to understand deeply the concept. I’m sorry for my unproper terminology – anyway can we assume this is right?
Every panel has it’s own gamut – maybe exceeding or lacking 100% of adobe rgb / srgb / dci p3 / rec etc
A) If I set an embedded profile in my monitor via OSD I’m just applying a filter that’s limiting the colors to the speciefied selected profile (adobe, rgb etc) before windows / GPU modifications, right? So I don’t need to change the settings in windows or inside the apps because I’m displaying more or less the factory calibrated profile.
B) If I don’t set an embedded profile via OSD (or having the default one – we can say uncalibrated) I’ll have the full and free gamut, matching or exceding at the same time all of the color profiles. If I want to set a color profile for working in a specified color space I have to set it manually in windows or inside a specified app (like photoshop). So I’m just applying a “color filter” after the monitor, in the windows space. Right?
C) In the end, calibrating manually the screen with a probe is going to create a video profile to enhace at it’s maximum the panel color features and balances the other parameters – but this is still not precise because it still falls out a precise color space and could be satisfying only for ourself (because the others are 90% not going to see what I am seeing). So I cannot “calibrate” an adobe RGB or DCI space with a probe, I just can calibrate my screen for my own pleasure on its own color space.
So If I want to set, for example, a DCI-P3 or an ADOBE RGB color space limitation I just need to use a universal ICC Profile for Adobe or DCI that will cut everything outside of it, is this right? I say universal because I think its a color space already defined – but my monitor will display less or more of it without “cutting it” with the profile “mask”.
I was intrested specifically in DCI P3 space because I work with graphics and photography and it seems the extension of sRGB space (srgb falls completely into DCI P3 triangle) and I’ts also actually supported, maybe not ever at his 100% by some high end phones , tvs and other video display. At the same I’m not really much intrested in adobe RGB since it suits only for high end photography and printing – and I’m not doing this.
Not exactly that. Every panel has a colorspace that when intersected with another colosrace gives you a % of intersection covering, you got that. But,
Displays HAVE NOT embeded profiles, some of them have gamut emulations, limiting their colorspace to “something”.
If you set that monitor to use full colorspace, you need a file “display profile”, ICC/ICM, that describes how it behaves. You register that profile in OS so OS knows how their displays behave.
If you do that, you can use color managed apps: for example open adobe PS create a sRGB image… no need to change things inside PS. It just works as long as each image has an asociated profile (like sRGB/AdobeRGB). No need to set “display profile” in Photoshop, OS knows “display profile”.
If you set OSD to a gamut emulation from factory (AdobeRGB), you need to do the same thing at OS level so OS knows how display behaves. Trusting a factory calibration is a bad advice, so it is to buy a widegamut without a measurement device. But if you want to do that, asociate in OS that display and generic colorspace profile, like AdobeRGB1998.icm. Display profile won’t limit gamut, it’s internal gamut emulation which does that. Profile just says to OS “I behave in ABCDEDF way”.Color managed apps use that info, profile info (ICC/ICM file info, provided by OS usually upon app request), to render images properly. It works in native gamut, or AdobeRGB or sRGB modes as long as OS known (via profile) of a display behaves each time. If OS display profile and display behavior (OSD mode) do not match, you get wrong colors.
Apps without color management, like most video Rec709 editors, do not care at all about display profiles. This is the reason you have to rely on colospace emulations INSIDE monitor (=NOT profiles). In those apps display should match content colorspace.
For example AFAIK Sony Vegas is not color managed. So if you have a widegamut, you need to use some Rec709 gamut emulation (2.4 gamma or less likely 2.2). You switch OSD mode to that kind of preset (not recommended) or better use HW calibration in that monitor (if present) to emulate that colospace. Once you do that, you can use Vegas and work in your Rec709 HDTV videos.
HDR videos with P3 encoded in Rec2020 is more complicated. Having a P3 display is not enough, you are likely to need another steps if display doe snot provide them. There are other therads about it.Summary:
-displays have not embeded profiles
-some displays have gamut emulated modes (limited) or user can made that custom emulated modes.
For color managed apps:
-OS (and apps through OS) knows how a display behaves by using/associating ICM profiles to that display.
-OS display profile and current display behaviour (OSD mode) should match
For non color managed apps:
-display should match contentPS. in Diplaycal what is the exact difference between “Gamut Coverage” and “Gamut Volume”?
Intersection (first) vs size (2nd). Size can be twice the other but intersection be 10%.
