sRGB Test Bench

The NEC EA244UHD has a built-in sRGB mode that is used for all of these measurements. SpectraView II can only calibrate the NEC to native gamut and while CalMAN 5.3.5 can use ICC-aware patterns for doing measurements, we do not use that option. Most programs are not ICC-aware and we want to show the most real-world performance that we can.

  Pre-Calibration Post-Calibration,
200 cd/m2
Post-Calibration,
80 cd/m2
White Level ( cd/m2) 202.6 198.5 80.5
Black Level ( cd/m2) 0.2677 0.2783 0.1143
Contrast Ratio 756:01:00 713:01:00 705:01:00
Gamma (Average) 2.06 2.17 2.37
Color Temperature 6347K 6734K 6593K
Grayscale dE2000 2.48 0.46 1.3
Color Checker dE2000 2.21 0.79 0.87
Saturations dE2000 2.42 0.78 1.1

The sRGB mode has a slightly red tint to the grayscale that gets worse as you get closer to 100% white. The gamma has a larger issue with it falling below 2.0 past 70% and giving us an average gamma of 2.06. Even with this gamma issue the color checker has a very good average error of 2.21 and the saturations error is only 2.42. The largest issue we see is actually the 100% white error, and this is something that calibration can usually correct quite easily.

As expected, calibrating to 200 cd/m2 using CalMAN gives us an RGB balance that is almost perfectly flat. The gamma drops down a bit at the end, but I expect we will see this happen more as I move to 256-point readings instead of 21-point. If I drop the readings back down to 21 it looks virtually perfect, so I wouldn’t worry. The grayscale dE2000 has an average of 1.0, so it is very good.

Color saturations are not adjusted, but the luminance is adjusted because of the improved gamma after calibration. This lets the color checker error fall to 0.79 on average and the saturations error fall to 0.77. Both of these are incredibly good and it means you won’t see any flaws when using the NEC EA244UHD after calibration. The contrast ratio takes a small hit from correcting 100% white, but not a major one.

Calibrating for the sRGB gamma and 80 cd/m2 also produces results that are very good. They are not as good as at 200 cd/m2 but are still good. I included gamma using both 21-point and 256-point charts so you can see the difference it makes in reporting. I don’t see this gamma issue past 90% that the chart indicates, but I also don’t do much work with nearly-white images. Overall these results are great and only look not-great when compared to the 200 cd/m2 ones.

I wish that SpectraView II could calibrate the gamut of the EA244UHD for sRGB but it doesn’t need it. If you own the hardware that can calibrate it you can use software like CalMAN or DispCalGUI and get fantastic results.

Brightness and Contrast AdobeRGB Test Bench
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  • MrSpadge - Monday, August 11, 2014 - link

    I agree, I'd rather give 24" at 1440p or 1600p a try, maybe also 1600p at 27", than any 4k display. At this point I could probably avoid scaling and make good use of the added pixels while avoiding all the drawbacks of 4k displays.
  • know of fence - Friday, August 8, 2014 - link

    4K at 24" is not nearly enough that is needed for sharpness, what's needed for sharpness is un-discernible pixels seen from the minimum distance (~12") that an eye can still focus, famously branded "retina".
    The TV/PC market is quadrupling pixels because it is the integer multiple (9x;4x) of 720p and 1080p, thus allowing artifact free scaling of both. Mr.Heinonen, the reviewer, should have scaled dpi to 200 %, not 150 %. But at least these monitors offer the option to have really small font/symbols, for some, IMHO crazy people. The goal is to have scaled font, video but native high res pictures.
  • MrSpadge - Monday, August 11, 2014 - link

    "what's needed for sharpness is un-discernible pixels seen from the minimum distance (~12") that an eye can still focus"

    That's only needed for sharpness if you're watching your 24+" screen from 12". BTW: minimum focal distance is around 10 cm, give or take a few depending on the age of the person. That's just a few inches.
  • psonice - Thursday, August 7, 2014 - link

    I think a lot of people miss the point with these monitors. It's not to get higher resolution / screen space, but to get a much clearer screen with the same space.

    As such, I'm looking to get a 24" 4K screen specifically. I'll run it at 1920x1080, with 2x scaling. That will give me a standard 24" screen res (and 1920x1080 is big enough for my needs, and easy on my eyes) but it'll be *crisp*.

    As a coder, I'm staring at a screen full of text all day, and having worked on a retina macbook pro for a while I can say that the screen on them makes text a lot more legible - it really is a huge improvement. So I want that, but bigger :)

    (And yes, I'd like a 27" screen even more, but I'd want >4K resolution then..)
  • Stephen Barrett - Thursday, August 7, 2014 - link

    this! i do the same on my xps 15. 2x scaling works great
  • seapeople - Saturday, August 9, 2014 - link

    I'm a little confused, I thought that if you run a 4K screen at 1920x1080, then it will basically pixel double and therefore be indistinguishable from a 1920x1080 screen running at native resolution.

    So you would be completely wasting the 4x pixels on the screen, and could save a lot of money by just buying a 1920x1080 screen.

    I wonder if you are confusing this 4K screen with Apple's implementation, whereby they render text at full resolution, thus giving you high resolution and crisp fonts, but then can double scale bitmaps so they are at least not blurry.
  • MrSpadge - Monday, August 11, 2014 - link

    He's probably referring to using 200% scaling instead of setting 1080p resolution.
  • MykeM - Thursday, August 7, 2014 - link

    Too high of a DP? Not at 183ppi especially when this is the perfect display size/density if you're moving from a 24" display @ 1920*1200. With he exception of getting the more preferable 16:10 display, this is one fits the "Retina" terminology perfectly.
  • thewhat - Thursday, August 7, 2014 - link

    I thought it was common sense by now that high PPI displays should be used with scaling...
    Yes, it sucks that a lot of software still hasn't caught up, but hopefully hardware like this will help to push in that direction.

    I wouldn't want to use a monitor bigger than 24-27", because that wouldn't work well for my FOV (related to viewing distance). So I'm glad there are sub-30" 4k monitors.
  • CSMR - Thursday, August 7, 2014 - link

    The difficulties of supporting widely divergent PPI displays well are very large.

    Currently Windows has a single dpi setting per user, and that works well for most software.

    However if screens differ widely in PPI, then a single dpi setting will not do, but supporting per-screen dpi is very difficult. Imagine having two screens, perhaps a laptop screen and external monitor, one with low PPI and one with ultra-high PPI. What happens when a window crosses both screens, or is moved from one to the other? You cannot expect apps to be able to deal with this, and only by removing the ability of apps to control pixels directly can this be dealt with. So both the OS and all apps need to be rewritten, and in a way that is not convenient for many apps.

    Until then the solution is to have screens with similar dpis so that a single dpi can be set in Windows.

    That is why I would avoid ultra-high dpi screens unless I know that there will be a single computer connecting to it and that computer will not need to connect to other screens. Moderately high dpi is best because their sharpness is already excellent and you can set say 125% or 150% in Windows and still connect to normal dpi screens without much problem.

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