White uniformity issues - do you have them too, did you check?

VarHyid

I recently went through five ASUS PG279Q monitors, every single one of them had massive white uniformity issues. Basically there were yellow-tinted patches on the screen which you could easily spot, as shown on this image: https://imgur.com/nYcpLQa

People said that this is a known issue of the AU Optronics panels, but apparently Acer (who uses the same panels) has better quality control so you're less likely to get a defective unit... so I bought the XB271HU and... it's the same issue. Granted, it's to a lesser extent, the discolored patch is in the upper-right quadrant, but it's still there. When I scroll a page with bright backgrounds and follow one spot with my eyes, I can see how it changes from brighter warmer tint in the upper area compared to the lower area and the whole far right side has a much cooler/darker tint. Here's how it looks like: https://imgur.com/xdyoIaX

My question is - do you have these issues too? It looks like everybody keeps focusing on the backlight bleed, yet none of those 5 ASUS monitors or this Acer had any bleed, but all were non-uniform. Did you check for uniformity? I know it's a "gaming" screen and you may not notice it in gaming, but when you open a website with white or gray background or scroll through your mails in Gmail, do you see the change in color temperature either left-to-right or top-to-bottom? I wonder whether a uniform high-speed IPS panel even exists.

RidingTheFlow

Not everybody have uniformity issues - but its simply because some panels are ok(ish) while others are atrocious. Hence its possible to find one which looks better - e.g. I was able to after ~3 replacements.
This is simply because they don't really include uniformity tests in the QC - or, actually, they rather relaxed (simple 9-point measurement +-20% I believe, at least from datasheets I've seen).

For these market segments (gaming, home consumer) its considered that majority of customer base does not care about solid colour uniformity anyway - because they mostly watch movies, play games or display some picture on it when you don't notice it.

If you want monitor with panel graded for uniformity, you need to go into pro or high-end business segment (just don't go for ASUS or Acer since their "pro" models are simple re badge and no sane professional would consider them).

VarHyid

If you want monitor with panel graded for uniformity, you need to go into pro or high-end business segment.

Well, here's the problem. Those pro panels are all 60Hz and ever since I experienced 120Hz there's simply no going back and I'm not just talking about gaming, even using the cursor on the desktop or scrolling websites feels choppy at 60Hz.

Besides, when did looking at a website or watching a movie became a "pro" usage? Yes, movies are also ruined by this - I look at a scene with a bright-blue sky and on one side the sky it much brighter, almost white with a yellowish tint. I wonder if that's because the sun is closer to this side in this scene and then when the camera rotates I see this white/yellow patch follow the scene so it's not in the movie, it's the monitor's fault. How is that in any shape of form considered acceptable even for media/entertainment?

Also, when did we get here? Every single "home consumer" screen I've ever owned (two Samsung monitors, one BenQ monitor, one Sony TV, two laptops - one even from ASUS, 3 tablets, phones etc.) is actually perfectly uniform, or at least uniform enough that when I look at a white screen, it's the same brightness and color temperature across the screen.

Anyway, congrats that you've managed to get what I'd consider a "non defective" monitor after 3 replacements. This alone sums up the problem, you shouldn't have to replace it at all or maybe just once if you get very unlucky. This is like buying loot boxes where there's a 10% (or less) chance of getting a good monitor in them

RidingTheFlow

Ultimately for high refresh rate in particular you will have to compromise, I haven't seen a high refresh panel which provides same contrast & gamut as 60Hz one. I've asked people familiar with LCD tech and was told this is mainly due to need to make LCD shutter "thinner" to allow for it to react/switch faster - so you get more IPS glow (and corner bleed due to this). 

Generally, larger the screen, more chance to get one with uniformity problems. Does not mean you will get one - as you've mentioned you had lot of screens before that were just fine. 

I am simply stating the fact that ultimately what is a "defect" is what was not as promised. You can't say that panel is defective if 100% perfect uniformity (or even 90% uniformity) wasn't specced in first place.

The unfortunate realities of modern monitor & panel market, sadly. Throwing away panels with uniformity issues is expensive and monitor manufacturers are not doing it simply because they prefer to accept some returns (later finding less picky buyers for refurbs).

VarHyid

Good point.

Reg. defects - technically that's true and frankly, I'm not expecting absolute perfection. Backlight bleed doesn't bother me much if it's not super extreme, IPS glow - no problem. Dead pixels - had 3 in the past, also no problem since they weren't in the center of the screen. Basically my rule of thumb is - if I can't notice a problem (or it's not bothering me), then it's not a problem for me.

That said, I consider something a "defect" if it is a very clearly noticeable problem that's different from the "reasonable expectation" one may have about a certain product. If you buy a toaster where the handle doesn't stay down and you have to manually hold it down for the entire duration of toasting the bread, then technically it's not something that was explicitly promised and the toaster still does the job of toasting the bread, but such flaw is not what you'd expect. Similarly, those monitors were still "showing picture", but it was "distorted" by the very noticeable and rather significant discoloration. That's why I'd call it a defect as I did not expect this from a screen.

You're right, though, if most people either aren't bothered by this or use those monitors JUST for gaming and may not notice it, there's no reason the manufacturer should change anything. Sad, but true

Ksi01

I had 3 replacements and everyone had uniformity issues (yellow to bluish tint). Not sure if i should just keep this one (only left side is yellow)

VarHyid

Meanwhile I've got a second screen and it's pretty much perfect in terms of uniformity so... case closed for me

Acrook

1. Dead pixel

A dead pixel is a picture element (on the display screen) in which all the colors RGB (red, green, and blue) are permanently turned off/ damaged; this creates a black spot in the display. The damaged pixel does not receive any power; hence the pixel turns black.

Dead pixels are black, and no matter how much your screen changes, these pixels remain fixed in one spot and won't change their color.

What are the reasons that cause dead pixels?

Dead pixels can result from manufacturing defects, physical damage, strong direct rays or light sources, etc.

Not even one dead pixel is acceptable as it is quite visible on the screen and causes disruption of the image quality. Dead pixels do not spread, but if there's more than one dead pixel visible on a screen, then there's a chance of some unread pressure.

What are the reasons that cause dead pixels?

Dead pixels are permanently damaged and cannot be fixed. Stuck and warm pixels can be fixed if proper measures are taken on time.