Artifacts in dark scenes?

DAOWAce

DAOWAce

Limp Gawd
Joined
Apr 8, 2007
Messages
139
Owner of a PB298Q. Former owner of a FG2421.

In scenes that transition into blackness there's this horrible, blotchy/blocky artifacting at the edges of the transition, almost like the display mode changes to 8bit or something. Edit2: Better words from a friend: "it looks like an oil slick"

0% brightness: http://i.imgur.com/PgW8nIp.jpg
100% brightness: http://i.imgur.com/N61qOu9.jpg

Old monitor:

0%: http://i.imgur.com/x8SxOuv.jpg
100%: http://i.imgur.com/Gb0TrpB.jpg

Image taken from War for the Overworld. Raw image for comparison on your monitor, please let me know if yours exhibits it too: http://i.imgur.com/uLaeMRK.jpg

Notice how on the old monitor (HP f2304; 10 years old too) it transitions perfectly to black whereas on the new monitor it discolors and artifacts before reaching pure black. This makes gaming in dark scenes problematic and disgusting to boot. This also happened on the FG2421 (returned it), which was even worse because of the high contrast ratio VA panels have, not to mention it had temporal dithering.

I can't seem to find any information about this on the internet. Not from user comments, user reviews or professional reviews. Nobody seems to even know this issue exists.

I've done all forms of monitor tests and everything checks out fine, but when looking at images, videos or playing games, the problem is present.

Does anyone know what this could possibly be from, or what it's called? Is it something to do with the bit depth? The color gamut? I am clueless.

Edit: More info in my later post. Seems to change in severity when the contrast goes over/under 60. Sometimes it's 59->60 that it changes, sometimes it's 60->61. I don't understand this. I've still yet to find any remedy after a year.

That picture is only one case of it. I was trying to setup a Diablo 3 light radius shot too, but my ISP decided to have an outage, and we all know D3 isn't playable offline! The light radius ring showed a pretty horrible artifacting in a very different way, wish I could get it, but hopefully this is enough for diagnosis.

Here's 2 more raw images that exhibit the problem greatly to test with, mainly blocky artifacting: http://i.imgur.com/bKzfgy8.png and http://i.imgur.com/RXp8kfI.png
 
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Search "LCD clouding" - do an image search also, are your symptoms different in any way?
 
The results I'm finding seem to be either about dust buildup behind the screen or some weird backlight uniformity issue across the display (which makes it look like clouds). This does have backlight bleeding issues (bottom sides have a bit of bleed, apparently because of the 21:9 format), but does not have that clouding issue. (like this, or this)

The issue looks something like low color depth and banding put together. It's only in the transition to pure black. Lit images look completely fine and pure black images also look completely fine.

I'm going to try and get a camera from my family so I can take a few shots between both my monitors. My old one (HP f2304) doesn't have the issue (just worse black levels due to being so old and using a CCFL backlight).
 
yea, post some photos - may help.

You mentioned monitor tests - what kind of test patterns have you used to assess your display?

For example, have you loaded up a full screen grayscale ramp?
 
Everest (now AIDA) tests, http://www.lagom.nl/lcd-test, http://www.testufo.com, maybe a few misc other ones I can't remember.

I see no real issues in anything, unless you count greyish blacks in dark scenes (IPS + W-LED backlighting, yay) and minor backlight bleed (or at least, a glowing effect from the corners).

This only seems to be an issue in some images, all videos and all games.
 
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blocky transitions could simply indicate compression artifacts that are visible due to too low a gamma. In games, perhaps shadow detail is being lifted too fast, causing visible contouring. Does turning down the brightness help at all?
 
Lunas said:
like this? http://psvitaforum.com/threads/how-sony-could-fix-the-oled-black-spot-problem.5266/
Click to expand...
Not a spot problem, no.

spacediver said:
blocky transitions could simply indicate compression artifacts that are visible due to too low a gamma. In games, perhaps shadow detail is being lifted too fast, causing visible contouring. Does turning down the brightness help at all?
Click to expand...
Brightness at 0% or 100%, doesn't change anything. (I run 0% on this monitor, 5% on old one).


Managed to get some pictures, adding them to OP:

0% brightness: http://i.imgur.com/PgW8nIp.jpg
100% brightness: http://i.imgur.com/N61qOu9.jpg

Old monitor:

0%: http://i.imgur.com/x8SxOuv.jpg
100%: http://i.imgur.com/Gb0TrpB.jpg

Not sure why there appears to be a light source on the old monitor pics; room was pitch black and it didn't look like that in person.

Here's the test shot I used so you can see how it looks on your monitor: http://i.imgur.com/uLaeMRK.jpg

Edit: Thanks to a friend, I've now got a more accurate description: oil spill, or oil slick. Managed to get a google result about it, but that's all I can find, everything else is completely unrelated to monitors: http://hardforum.com/showthread.php?t=1783370
 
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those oil slick patches aren't an added artifact - they're part of the image. The reason they stick out so much is because the luminance of those pixels are too high, relative to the background.

This could be because of backlight bleed, or because the gamma is too low on your display (either because the display is defective, sucks, or is calibrated incorrectly, or because the video LUT has been tampered with).

Turning the brightness down did reduce the problem according to your photos.
 
What display mode is the monitor in? Standard, theater, game, sRGB? Also, what is your gamma, contrast, and brightness set to? And what were the default values?
 
Lunas said:
contact asus for warranty replacement.
Click to expand...
Is it really a defect with the monitor, or is it a design issue with the panel being used?

spacediver said:
those oil slick patches aren't an added artifact - they're part of the image. The reason they stick out so much is because the luminance of those pixels are too high, relative to the background.

Turning the brightness down did reduce the problem according to your photos.
Click to expand...

I've never seen anything like it before in my life though. Both my CRTs, my old (2004 H-IPS) LCD and now my new LCD; this only shows on the new LCD.

Checking the lagom gamma test, it's about 2.25 (varies based on display mode, only gamma option in settings is changing it between 1.8 or 2.2)

I normally use 0% brightness (and even that's a bit too bright for my taste). The picture with 0% brightness looks far reduced, but only in the pictures. It's very noticeable in person, whereas 100% completely washes it (and the whole image) out, and makes the monitor look like it's glowing from how bright the LED backlight is.

John721 said:
What display mode is the monitor in? Standard, theater, game, sRGB? Also, what is your gamma, contrast, and brightness set to? And what were the default values?
Click to expand...
Standard display mode. 2.2, 63 and 0. Don't know the default values (and really don't want to reset it), but they were probably 2.2, 80 and 80, considering the other modes all have brightness/contrast maxed/near maxed.

I've cycled through all the various modes and the problem doesn't quite disappear, but lessens or gets worse depending on the mode.



However, while playing around with the settings, I noticed this issue shows severely above 60% contrast. Once it goes from 60 to 61, the issue really shows up. That boggles my mind; how could it shift so bad in one step?

I've now lowered my contrast to 60% (from 63%, so no big deal), and it's heavily reduced.. but still not perfect.

This is, aside from the not so good black levels, my main gripe with the monitor (other being not letting me select color temperature). I'm not too knowledgeable about the in-depth stuff relating to monitors, so I'm not sure where to go from here, short of trying to see if a replacement monitor would fix it, or get in contact with someone knowledgeable from ASUS and have them look into it.
 
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OP, are you using in game or driver gamma/brightness settings?
 
Monitor?

I only ever adjust ingame brightness if I need to see something better for ease of playing, which is fairly rare.

I don't touch any driver color stuff.
 
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might be worth hooking up the display to another PC just to make sure it's not on the PC end.
 
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