XL2420Z uneven brightness/contrast issue

[martinso]

I have noticed that top part of my XL2420Z screen is little darker than the bottom part. It’s not very noticeable in games, but can be seen while browsing some web pages and in desktop work.

I tried adjusting display settings in nvidia control panel and in monitor itself, but nothing helped. I don’t think it is a viewing angle issue, as I am sitting perpendicularly to the monitor.

Is this normal for these 144Hz TN screens and I am just too picky? Or is there something I can do about it? I know TN panels have their flaws, and I don’t expect perfect color accuracy, but at least even image across the screen.

[VarHyid]

Go to this page: http://www.lagom.nl/lcd-test/viewing_angle.php and make it fullscreen. What do you see? Is the top darker or is it harder to see the writing? I have the same monitor as you and the top line in this test is harder to read if you have your eyes lined up with the top bezel of the screen. It gets worse if you'd look at the middle of the screen, hence - seems like a viewing angle issue.

As another test, try this one: http://www.lagom.nl/lcd-test/clock_phase.php - here, on my XL2420Z there's no noticeable dark spot at the top (again - looking at the screen with my eyes lined up with the top bezel).

[martinso]

Go to this page: http://www.lagom.nl/lcd-test/viewing_angle.php and make it fullscreen. What do you see? Is the top darker or is it harder to see the writing? I have the same monitor as you and the top line in this test is harder to read if you have your eyes lined up with the top bezel of the screen. It gets worse if you'd look at the middle of the screen, hence - seems like a viewing angle issue.

Yes, the writing is harder to see on the top as you described.

As another test, try this one: http://www.lagom.nl/lcd-test/clock_phase.php - here, on my XL2420Z there's no noticeable dark spot at the top (again - looking at the screen with my eyes lined up with the top bezel).

It looks pretty evenly on my screen too.

I made some tests to better represent my problem. Here are two test images (better view at fullscreen):

1) Black – Dark Grey test
http://i.imgur.com/vhllC2m.png

2) White – Light Gray test
http://i.imgur.com/6rXz578.png

Try first test. Can you see gray squares on the very top of your screen or does it look all black on the top?
Now try second test. Can you see gray squares on the bottom of your screen or does it look all white on the bottom?

On my screen I can’t see both tests correctly regardless of the viewing angle. Either one test or another depending what display settings I use.

[Falkentyne]

This is by design. You're using a TN screen. And that's how they are.

Try standing at the far end of your room and looking at that test.
You will see that the top and bottom, while not 100% identical, look VERY close and you can see the entire pattern now, almost evenly.
The farther away from the screen you are, the closer the uniformity. I just stood at the far end of my room on the white pattern test and it is almost uniform at the very far of my room. But if I get close to the panel, like, sitting in a chair at normal position, then the bottom is pure white.
It's exactly the same on my 2720Z and on every TN panel. It's just how TN panels are.

You need a VA or IPS panel that doesn't have gamma/color shift from viewing angles (or a CRT) or laser projector.

[VarHyid]

Martinso, here's the thing - technically, this is indeed "normal" for a TN panel, but it also may depend on your settings/calibration and of course your viewing angle. The way I look at my screen is like on this image: http://blog.codinghorror.com/content/im ... 70c-pi.png - I find that in this position, I don't see any issues at the top, and even though it's a little bit brighter at the bottom, I don't notice it. If I'd put the monitor higher so that I look directly at the center of it - then it can get bad because all TN panels handle viewing angles "from the bottom" very badly.

That said, it's also something you may adjust with the settings (or rather - based on the settings, you may make it less noticeable for most situations). I personally like deep blacks and rich colors (duh! ) so the way I calibrated my screen is that I basically do not see ANY squares on your first image - none at all, it's a 100% black image for me. If I switch to a different profile - I see them and yes, they're bad at the top.

On the second image, however, it's almost perfect. No issues neither at the top nor bottom... unless I switch to the other profile then, just like you say, it's too bright at the bottom.

Calibrating the XL2420Z is a huge pain and the biggest gripe I have with it. The reason is that it locks certain options depending on what fixed preset you choose and you can only calibrate it by using a "preset of reference". For example, if you (and for the love of God, please don't ever do this ) go to the FPS1 profile, you will experience the worst color palette ever used on a monitor and this includes prehistoric cave drawings In fact, it is physically not possible to get yellow right... ever, in this profile.

That said, however you'll calibrate it when you start with FPS1, it will always be bad because it will be "adjusted FPS1 mode". In other cases, you may not have access to some options so personally, I found only 2 presets that make sense to start with:
- Standard
- Photo

If you start with Standard, you will get the most "correct" image, but when I say "correct", I mean - the one in which you will see gray squares on the first image. The downside is - kiss deep blacks goodbye.

If you start with Photo, you will lose the ability to see the dark grays on the image, but in general, you'll get a quite uniform picture with quite deep blacks (note - the keyword here is quite, of course, unless you get an OLED screen, the idea of "deep blacks" is very relative).

These are the settings that I have settled for. The first is what is objectively considered "incorrect" because you'll lose dark grays, but I like it because the image is vibrant in general, I get nice blacks etc.
- Switch to "Photo" as the origin preset.
- Set brightness to 0
- Set contrast to 10
- Low Blue Light = 0
- Black eQualizer = 0
- Color temperature (User mode): R = 85, G = 75, B = 50

Again, my personal preference for my "dark room", you may want to play with brightness/contrast if you're in a bright room, but in general, with the settings above, I get the image to be closest to an IPS screen from my Xperia Z2 tablet.

The "alternative" solution that will be the "correct" one if you want some dark grays is:
- Switch to "Standard" as the origin preset.
- Set brightness to 0
- Set contrast to 5
- Low Blue Light = 0
- Color temperature (User mode): R = 100, G = 90, B = 65
- Gamma = Gamma 5

Remember to save to a custom "Gamer" profile for re-use, if you like

Oh and... I'm running it via DisplayPort at 120Hz, I find 144Hz to be the nail in the coffin of the color palette and frankly, as much as I see the difference between 60 and 120Hz, I don't see it between 120 and 144Hz, but that's a different story.

Anyway, the point is - your screen is fine, you're experiencing the regular TN properties, feel free to try my first settings to get a most uniform image for the white test. You'll see nothing on the black test, but again - it's a preference, it may not bother you "in action" (try some games), if it does... play around

-----EDIT------

PS. Disclaimer - if you start with the "Photo" mode, you won't be able to use Blur Reduction. That's one of the gripes I have with the monitor - why can't Blur Reduction be available regardless of the profile, I have to choose between a picture I like or one that I like less, but one in which can use Blur Reduction... oh BenQ

[martinso]

Thanks for your replies.

Currently I’m using display settings and ICC profile from pcmonitors.info website which looks quite nice, maybe little dark for my liking, but colors are good. I prefer to see dark greys as it helps to see more detail in games in darker areas. I really wish there was one display setting to use, cuz switching profiles for different tasks is kindof lame..

Can’t wait to see when those 120Hz IPS screens become available.

[VarHyid]

Wow, their settings are crazy over the top blueish, but... different strokes for different folks

[Deex]

Wow, their settings are crazy over the top blueish, but... different strokes for different folks

Have you tried ICC profiles? I am slightly frustrated with this panel.. its a great panel but I cant seem to get it right.. either my viewing angle sucks or my colors are off.

I see that ASUS has a MG279Q 120Hz IPS monitor coming out lol .. might just consider that.

[VarHyid]

Wow, their settings are crazy over the top blueish, but... different strokes for different folks

Have you tried ICC profiles? I am slightly frustrated with this panel.. its a great panel but I cant seem to get it right.. either my viewing angle sucks or my colors are off.

I see that ASUS has a MG279Q 120Hz IPS monitor coming out lol .. might just consider that.

I did try the profile. In the end, I figured out my "perfect" solution with a combination of monitor settings and Nvidia's panel.

I'm using the "Standard" profile in the monitor with Brightness 0, Contrast 10, Gamma 5, Red = 100, Green = 90, Blue = 65 and then in the nVidia control panel, I just put Gamma to 0.85 and Digital Vibrance to 56%. Running at 120Hz.

It looks fantastic to me when it comes to colors. As for viewing angles... well, it's a TN panel. Looking at it with my eyes aligned with the top of the screen, it's as "uniform" as I'd expect from a TN panel, but sure you can't expect perfection. It's the last TN panel I've bought, I'm keeping it until I can get a 4K OLED screen

[martinso]

Wow, their settings are crazy over the top blueish, but... different strokes for different folks

Have you tried ICC profiles? I am slightly frustrated with this panel.. its a great panel but I cant seem to get it right.. either my viewing angle sucks or my colors are off.

I see that ASUS has a MG279Q 120Hz IPS monitor coming out lol .. might just consider that.

Switching from IPS to TN panel was sure a disappointment in picture quality, but now I’m getting used to it, as there’s nothing much you can do about it.