Identical monitors - mismatched color

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bencho

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Hello!

It's been forever since I've had multiple monitors. Just got a second LG 34UM88C and the colors are slightly off - most noticeably, the whites are perfect on my first monitor, but the new one is slightly tinted yellow.
  • I've configured the same settings in the onboard options
  • First monitor is Displayport, second monitor is HDMI
  • Color management options are default
    • Use my settings is NOT ticked
    • ICC profiles show SRGB profile with display hardware configuration data derived from calibration
  • GTX 780
Am I missing something obvious here?

Also dumb item here but Windows 10 - why can't I set individual wallpapers per screen? Google tells me there are options for independent screens and yet I don't see them..
 
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Just because they're the same model doesn't mean they're physically identical. This is why people who are interested in color accuracy calibrate their displays based on the response of the individual display rather than to the average response of a particular model. For example, differences in backlight uniformity, or the spectral properties of this backlight could contribute to this, but if the difference you're seeing is really noticeable, it might indicate something else is going on.

I just looked up your model, and it looks like it can be hardware calibrated. I take it to mean that this means that colors can be controlled directly from the monitor itself, rather than relying on lookup tables via software. If this is the case, then you can probably do this without running into the limitations of software calibration (e.g. limited precision of adjustments resulting in crushed luminance levels), so you should take advantage of that. Best to get a colorimeter to do this though.

Also, have you tried switching the monitors around the ports, to see if the problem is at the port, or the monitor?
 
Hey,

Yes I do understand they won't be 100% but it's odd that they come calibrated from factory and the baseline of white is so different. That's why I suspect something in software is my issue.

I haven't tried swapping inputs. That's a great idea!

I'm not sure what you mean by hardware calibration. I thought all monitors basically have a RGB that can be tuned and gamma and whatnot options?

I guess something like colormunki or xrite is what you're recommending?
 
Since these are not professional grade monitors the factory calibration can be half-assed at best.

This is also the reason why copying someones calibration settings and adding a copied ICC profile on top of it is a stupid idea. At best it can make some difference to positive if they are close by luck, but most likely it will make matters worse.

If you want to make them look the same, you need a colorimeter. If you want to calibrate them to be accurate and follow some standard, Colormunki Display or i1 Display Pro are what to buy.

If you just want them to measure (and look) the same, a cheap Spider 5 will do. Its not a good meter and accuracy will most likely drift more in time but for making two displays look the same it will work.
 
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OK.

I do some photowork and for sure I want them to match.
I presume Colormunki Display or i1 Display Pro will create one calibration and then once I calibrate one monitor, it can just "make" the other ones match?
 
I use a Spyder5Pro. It creates an ICC profile which, if I understand correctly, is loaded into the video card for certain aspects of Windows and other color managed programs.
I must have spent an aggregate of over 50 hrs over the last few years trying to understand why colors look different in various programs (OS, browser, Photoshop, Lightroom)...and I stili don't get it sometimes.
The difficulty for my situation is that I'm using a wide gamut Dell U2410 (covers Adobe RGB) so the saturation/desaturation can be extremely skewed depending on content.

It looks like your monitor only covers sRGB though so that makes things simpler. My secondary Dell U2415 is also sRGB (Spyder calibrated it to 100% of sRGB) and is a much better reference for online content (browsers are not color managed other than Firefox with special settings activated, but this still is less than ideal because online media is often profile-less).

The biggest problem to the whole monitor calibration fiasco for photography though, is the lack of photo/picture viewer programs that are color managed and well implemented. The idea is that it's not convenient to load photos in Photoshop (which is color managed) since it takes a few seconds to rev up. I'm using Fast Picture Viewer for the purpose of quick viewing, but it can only load one ICC profile at a time and must be selected in the options manually. This means you'll need to select the proper ICC profile whenever you move a photo to the next monitor. In addition, if you're like me and save lots of cool photos from the internet (I use Chrome), many pictures have no embedded profile, so the expected proper color space for them is sRGB (internet standard). Now when Fast Picture Viewer opens up one of these sRGB or profile-less photos, the colors desaturate on the wide gamut screen unless color management is turned off or set to sRGB. What I still can't figure out is why I can't "resaturate" these profile-less photos when viewing them in PS using an sRGB working space on the wide gamut monitor. Meanwhile, dragging them over to the sRGB monitor brings the saturation back.

Sorry if that was hard to follow. Color management has been an ongoing battle for me. Long story short, get the Spyder, you don't have wide gamut monitors to worry about.
 
bencho said:
OK.

I do some photowork and for sure I want them to match.
I presume Colormunki Display or i1 Display Pro will create one calibration and then once I calibrate one monitor, it can just "make" the other ones match?
Click to expand...

No you choose a white point color temperature and gamma (6500K and 2.2 by default) and tweak each monitor indivudally and create ICC profiles for the individually. When both of them are adjusted to the same white point, both screens will look much closer to each other. Both have the same whites with all RGB channels balanced out (no more yellow whites on other and blue whites on other or such). Greyscale color temperature may still differ, but 1-point RGB sliders common in monitors cannot fix it. However ICC profile will take care of that. Simple greyscale and gamma fix does not even need color managed software since its applied to desktop too. Provided that the software does not reset the calibrations, which unfortunately a lot of games do.
 
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Just to add, the Spyder5Pro can take ambient room light measurements into account and you can specify your own color temperature and gamma. The default recommended white point is far too bright for me so I just set the brightness/contrast I like on the monitor and let Spyder do its thing. If you're considering another vendor, make sure their product supports multimonitors with their own ICC profiles. I remember the older Spyders did not have this feature.
 
MaZa - I'm beginning to understand a bit... I went and got a colormunki display. Playing with it now.

Thanks so far guys!
 
So I'm running the tests with Colormunki and the After is EXTREMELY more yellow to my eyes than compared with the Before. Is this normal? Or have my eyes just been more acclimated to a more cool tone??
:(
 
Are the both screens equally yellow? Thats just your eyes having a shellshock. 6500K is pure white but if your eyes are used to colder image it may seem bit yellow at first. Give it time and if you go back to the old color temperature it may seem very blue. :)

Ironically it seems that out of your two screens the yellow one was the one thats better factory calibrated. :p
 
bencho said:
I'm not sure what you mean by hardware calibration. I thought all monitors basically have a RGB that can be tuned and gamma and whatnot options?
Click to expand...

Yes, most monitors can be hardware calibrated to an extent (brightness is a parameter, for example, that virtually all displays have). But some have finer controls than others. The more you can do on the hardware level (i.e. through monitor controls) and the less on the software level, the better.

bencho said:
I guess something like colormunki or xrite is what you're recommending?
Click to expand...

You'd definitely need a color measuring device to perform calibration, whether or not you're calibrating through hardware or software, or both.

btw, you might find the intro to the WinDAS white point balance guide useful for some basic background into color theory and calibration.
 
bencho said:
I'm not sure anymore >_<

Primary one is still cooler than the other.
Click to expand...

Thats odd. You follow the instructions correctly? Adjusted the RGB sliders in your monitor until the calibration software showed that all channels are correct? On both screens? Then white point should be the same for both and neither should look noticeably cooler than the other as far as the color of white is concerned.
 
Not related to the yellow tone, but don't forget that your eyes are biased to contrast and saturation in relation to your room lighting conditions so calibration is not necessarily an end all.

If you calibrate in dark conditions right up against the screen for example (or are lucky enough to have a decently factory calibrated monitor out of the box) - then actually use a monitor in different lighting conditions or in variable lighting conditions, you aren't going see the same results to your eyes and brain as your calibration goal. That's why some people, myself included, keep 3 or more sets of settings on their tv's for different lighting and usage scenarios. Perhaps if there was some optical device setup similar to the tripod microphone setup for home theater surround receiver setups that could tweak the settings, but again unless your lighting conditions are static you'd have to leave the sensor(s) out and active all the time. I think it's easier just keeping a handful of saved tweaked settings for daylight, night, reading, movie, gaming.

Beyond that, you can also get direct light pollution washing out parts of a screen slightly even when it's an anti-glare screen, more of a fog like effect rather than a direct reflection but still an undesired result. So the best scenario is usually keeping all direct light sources behind the backs of the monitors. This makes keeping a desk against a wall like a bookshelf a poor setup since it is set up like a catcher's mitt for direct light pollution. Overheads or window lighting refracting directly off of the monitors are also a really bad setup.

Regarding the wallpaper question, you might want to look into displayfusion or displayfusion pro for wallpaper management. You can also make sure that desktop sync is turned off in windows 10, otherwise all of your windows logins will have the same wallpaper on different machines.
Settings -> Accounts -> Sync
Without displayfusion/pro which I highly recommend, apparently you can still access the old windows applet/UI

From a Run or CMD prompt:

control /name Microsoft.Personalization /page pageWallpaper
 
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So I rebooted last night and now both displays are MUCH more in sync in colour. This reinforces the adage of "reboot it" haha.

Last question here should help finalize this thread - the new screen is still a tad bit more yellow. To make a yellow screen more cool, am I supposed to INCREASE the blues only? I feel like it doesn't quite work out.
 
Best thing to do might be to use HCFR in free measure mode. That way you can adjust the monitor controls and see the effect on chromaticity in real time. My guide has the link to the latest HCFR and instructions on how to use HCFR in free measure mode. You should probably be targeting D65 chromaticity.

You can use the RGB bars in HCFR to see whether red, blue, or green needs adjusting.
 
I have 3x U3011s. Considered professional grade and pre configured to be RGB great for photographers and all that jazz (At the time).

They don't display "White" the same.

If you really want to get perfect calibration, invest in a Spyder. I haven't done it yet because I just don't care too much :p
 
Even in displays of the same model and make, it's very very hard to get a 100% match on whites and greys. I've tried this multiple times on my 27" NEC screens hardware calibrated with X-rite i1 and while they are quite close, it's never ever going to be a 100% visual match. A more accurate test than whites and greys is how photos look on both screens, properly calibrated screens with mostly identical gamut and backlight should be almost the same.
 
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