Quote:
Originally Posted by mclingo
Hi, this isnt strictly true. I have a first gen LG oled and I can tell you that if you put a good signal into it you'll get a good one out.
Being bad a near blacks seemed to be the mantra I LCD owners and reviewers pedalled a lot to the point where i believed it myself and spent what seemed to be hours trying to find out if I had a good or bad example of my TV as something else that was suggested was that some were better than others.
The issue with OLED is not that they are poor at near blacks, its that near blacks tend to house macroblocking and compression artefacts which aren’t masked like on an LCD.
This isn’t because LCD’s are good at near blacks per sey, its because it cant show pure black so where you would see a blocky black mess in a shadow on an OLED you would just see a smooth dark grey none black area on LCD. If you turn up the brightness on an OLED and lose pure black the blocks disappear. I have both an OLED and a fairly decent LCD so I know this to be the case.
This is most apparent on highly compressed streamed material, some of it is completely unwatchable but this is not the fault of OLED, it’s the source.
Later gen units have deployed some processing to deal with this but these source problems but I’ve heard that some stuff still looks pretty bad.
This is why I use MADVR, this really helps with compression artefacts and macroblocking to the point where some material is watchable again.
I good example of this is Snowpiercer, this was completely unwatchable some early OLEDs, you could crush some problems away but that would just make something else pop. With MADVR you can pretty much deal with all the problems by deploying reduce banding artefacts on high.
One thing new OLEDs are better at is quantisation errors at near black. Brightness on early units was quite notchy in that there would be a large jump between brightness 49-50 but then nothing again until 53. This could cause quantisation problems where you could get raised blacks but again only on poorly compressed material.
The latest SOLO movie is full of near blacks and greys, I have ZERO issues on my OLED.
|
Quote:
Originally Posted by SamuriHL
This is quite true. I come from a Panny plasma screen and I can honestly say the OLED is quite a leap forward. But you're 100% correct that it will emphasize poor source quality. Last night watching Mayans on my cable system where they compress everything to 720p59 at around 3mbps the night scenes were attrocious on my OLED. But that's not the OLED's fault! The source was highly compressed and the OLED didn't mask it. Nor do I think it should IMO. Black levels on this thing has been extremely impressive. Like you, I found Solo to be excellent on the OLED.
|
Ah, the good old "It's not the Oleds fault when compressed content looks bad" theory, that gets posted whenever someone complains about near-black artifacting issues on forums...
Not true, at least not when it comes to LG Oleds.
My 2016 C6 had very poor near black gradation and came out of black way to fast and there was no way to really fix this.
Now my 2018 C8 is very different. Near-blacks have smoother gradation and it doesn't come out of black so fast. Test pattern usually look pretty good.
But then why does this thing show terrible macroblocking/artifacting/flashing near-blacks in certain scenes??
Here is what's happening on 2018 LG Oleds (2017 probably too but I never owned one):
The way they implemented the better near-blacks seems to be a comrpomise. On a still image that is not moving everything looks fine, also test pattern usually look fine.
If I play such a scene that shows ugly macroblocking or flashing near-blacks and pause it, all the macroblocks and ugliness suddenly vanishes. If I hit play it appears again...
Now lets pause the scene (picture looking good) and use mpc-hc's pan&scan move function bound to keyboard keys to shift the picture around. What's happening now is that every time the picture shifts some of the near-blacks including macroblocks that were barely visible before flash up for like a split second, making it look really ugly. If I display the picture in a borderless window and move it around with my mouse parts of it begin to glow.
This effect doesn't show up in every near-black scene, far from it. Neutral gray is fine, it seems only certain colored near-blacks are affected, some more than others and that's why the flashing near-blacks effect doesn't show up in every scene. This issue is also present with high quality content like UHD Blu-ray but much more subtle. The reason for that I think is that on high quality content there usually aren't any rapidly changing larger areas of the same color like macroblocks. Though on scene changes and fade to blacks I can sometimes see it flash up and also during camera pans the edges of objects sometimes start glowing or some parts of the picture are flickering.
It's really weird as it seems like this effect only shows up when specific near-black colored pixels change to other specific colors and that's why only certain scenes are affected. It's kinda like the pixels are getting too much voltage to get them started and then they calm down.
Increasing the brightness on the TV to a certain point completely fixes this problem but it induces black glow and also makes the near-black gradation worse. I guess a lot of people who don't watch in a dark room do that anyway, as they don't care about black no longer being true black. Since there is such a big panel to panel variance on Oleds, some might even have some panel glow at default brightness and those will probably never experience this problem. Setting color on the TV to 0 also fixes this, which makes sense as from my observations only certain colored near-blacks are causing this.
When I first noticed this I thought it must be a defective TV but on the other hand I've found quite a few posts on forums where people reported similar issues but no one ever seems to really investigate this and then people jump in and tell the "Oled is so good it shows every flaw in content" myth...
So I requested a panel replacement from LG, not only for the here explained issue but also due to vertical banding and they agreed to it. When the technician arrived I showed him the flashing near-blacks issue and he immediately said that he has seen this problem on a lot of Oleds and he doesn't think a new panel would fix this and he also couldn't really explain why this is happening. He still agreed to install the new panel though.
It didn't fix the problem, it still showed during the exact same scenes as with the old panel, though the vertical banding is a bit better. What I also noticed is there seems to be a huge panel variance regarding the low end. The new panel is much darker on everything below 10% and has some heavy black crush. So comparing settings on Oled seems to be really pointless with such a variance from panel to panel.
Here are 3 screenshots if anybody wants to test this on their 2017 or 2018 oled. 2016s didn't have this problem, they had poor near-blacks from the get go even without the picture moving.
https://drive.google.com/drive/folde...tx?usp=sharing
To test this you need to shift the pictures around. Mpc-hc has controls for that (set them to keyboard shortcuts), or display it in a borderless window on a completely black desktop and move it around with the mouse or use the TVs live zoom to zoom in and pan the picture around.
Best to do this in a dark room at default TV brightness, technicolor default preset. Just make sure to have set the correct video levels. Also disable any madVR picture enhancements for testing.
As there is quite a big panel to panel variance I'm not sure if this test will even show the problem on every 2017+ Oled because slight changes in settings can make it better or even fix it in one scene but then make it worse in another.
Also some panels might be more prone to this than others, or might require different colored near-blacks to cause the issue.
The only thing that really seemed to fix it on both of my panels was to turn color to 0 or to increase brightness, making near-blacks brighter but this also results in black glow and worse gradation, so not really a good option.