[fafrd]

We keep hearing promises from LG that it will ‘fix’ the luminance overshoot issue, and yet for over three generations and 3 years now, the issue persists.

Overshoot from 0% seems to be intrinsic to WOLED and Rtings.com has been posting measurements since the first WOLED generation which clearly shows the overshoot: https://www.rtings.com/tv/reviews/lg/cx-oled

Looking at the 0-20% measurement, the overshoot looks to be about 2.85% luminance (~20% / 7), while looking at the 0-100% measurement, the overshoot looks to be about 2.5% luminance (~1/5th x 100%/8), so the overshoot appears to be a fixed luminance % in the best case and increasing in absolute value at lower luminance steps out of 0% in the worst case.

A 2.85% overshoot to 20% luminance is probably not going to be visible, since it’s less than 15% of the luminance increase / step, but assuming that same overshoot of 2.85% remains at a luminance step from 0% to 10% or even 5%, we’re talking about an overshoot of 28.5% to 57% of target luminance, so a luminance overshoot flash lasting 10ms in a dark scene will be visible, at least if several pixels in the same area overshoot at the same time.

From what I can tell, aside from ongoing panel-lottery issues associated with uniformity and near-black DSE, this luminance overshoot issue is WOLED’s biggest Picture Quality bugaboo.

Hopefully with LG now focusing more attention on the issue, they’ll find an acceptable workaround.

One idea that would probably work would be to break up the correlation - since they have some latitude on what luminance level to activate the white subpixel (which seems to be the primary culprit), breaking a thing up so every 10th pixel (or whatever) turns on it’s white subpixel at a different time / luminance threshold would go a long way to avoiding entire flashing / overshooting areas / lines / contours which are large enough to draw attention.

I hope LG finds an acceptable fix for this issue since a dark junkie like me considers any black-level anomalies a showstopper when selecting a new TV...

 

[lganz316]

Get a Panasonic GZ or HZ OLED if you can. LG is yet to fix this and near black detail.

Sent from my Moto G (5S) Plus using Tapatalk

 

[fafrd]

Get a Panasonic GZ or HZ OLED if you can. LG is yet to fix this and near black detail.

Sent from my Moto G (5S) Plus using Tapatalk

If Panasonic has found a solution, hopefully LG can as well (no Panasonic option here in the US).

But I thought I understood that even Panasonic suffered from similar luminance overshoot (but less noticable because they elected to only activate the white supixel at higher levels luminance levels).

 

[D-Nice]

If Panasonic has found a solution, hopefully LG can as well (no Panasonic option here in the US).

But I thought I understood that even Panasonic suffered from similar luminance overshoot (but less noticable because they elected to only activate the white supixel at higher levels luminance levels).

Correct and the new Sonys have the same scheme and consequences.

 

[fafrd]

Correct and the new Sonys have the same scheme and consequences.

D-Nice, greatly value your insight on these PQ issues and would appreciate your view on the following question:

If the Worst WOLED luminance overshoot you’ve ever seen is a ‘10’ and the issue being fully addressed to the point of never being noticable on actual content is a ‘0’ (not counting test patterns and video games), where would you say that Panasonic has gotten to on that 0-10 scale of addressing the issue?

And on that same scale, would you say Sony with the A90J is now at the same level as Panasonic or 1/2 or 1 step behind?

And finally, same question for LGE with the G1.

I’m just trying up get a sense of your view as to how far along the various brands are as to making luminance overshoot a non-issue when viewing actual content on WOLED...

Thanks for your insight.

 

[lganz316]

If Panasonic has found a solution, hopefully LG can as well (no Panasonic option here in the US).

But I thought I understood that even Panasonic suffered from similar luminance overshoot (but less noticable because they elected to only activate the white supixel at higher levels luminance levels).

Whatever it is, it is not that easily noticeable. My Panasonic GZ OLED handles compressed sources reasonably well then any of the TVs I have owned but where it falls apart is motion handling

Sent from my Moto G (5S) Plus using Tapatalk

 

[jk82]

Panasonic has absolutely not fixed the luminance overshoot.
They shifted it to a higher range but that just makes it behave different and affect other scenes compared to LG.

I got PMs from Panasonic HZ owners who asked me about the luminance overshoot because they have the exact same issue. So 2020 Panasonic models presumably behave the same and 2021 models aren't out yet but I somehow doubt that anything regarding the luminance overshoot will improve.

I would go as far as to say I prefer the LG C8 for SDR content compared to the GZ2000 I had because of this nasty issue.
Some content was imho unwatchable and that includes blu-rays and games, so you can't blame compression. I basically had to dither to 5-bit with madVR when watching SDR on the Panasonic to make it bearable. MadVR's dithering is way better than LG's but unfortunatley you can't solely dither the lower range.

Can't really say much about Sony as I've never had one but if they indeed 'fixed' it in a similar way as Panasonic then I sure as hell don't want a Sony.

I don't know exactly why but on my C8 when calibrating the 1D + 3D LUT and uploading it to the TV this somehow almost gets rid of the luminance overshoot. I don't even remember when I've seen it the last time in content. Uploading the 1DLUT with aiopylgtv or DeviceControl has the side effect of causing the TV to revert back to the original weak dithering method but surprisingly the overshoot doesn't return as bad as it originally was. Not sure if this also happens when using calman, does anybody know?

 

[fafrd]

Panasonic has absolutely not fixed the luminance overshoot.
They shifted it to a higher range but that just makes it behave different and affect other scenes compared to LG.

I got PMs from Panasonic HZ owners who asked me about the luminance overshoot because they have the exact same issue. So 2020 Panasonic models presumably behave the same and 2021 models aren't out yet but I somehow doubt that anything regarding the luminance overshoot will improve.

I would go as far as to say I prefer the LG C8 for SDR content compared to the GZ2000 I had because of this nasty issue.
Some content was imho unwatchable and that includes blu-rays and games, so you can't blame compression. I basically had to dither to 5-bit with madVR when watching SDR on the Panasonic to make it bearable. MadVR's dithering is way better than LG's but unfortunatley you can't solely dither the lower range.

Can't really say much about Sony as I've never had one but if they indeed 'fixed' it in a similar way as Panasonic then I sure as hell don't want a Sony.

I don't know exactly why but on my C8 when calibrating the 1D + 3D LUT and uploading it to the TV this somehow almost gets rid of the luminance overshoot. I don't even remember when I've seen it the last time in content. Uploading the 1DLUT with aiopylgtv or DeviceControl has the side effect of causing the TV to revert back to the original weak dithering method but surprisingly the overshoot doesn't return as bad as it originally was. Not sure if this also happens when using calman, does anybody know?

Appreciate your perspective on this issue.

I’ve got a C6 that suffers from reduced bit-depth near-black, but never exhibits overshoot that I’ve noticed on content.

From what you’ve stated, I’d probably consider a Panasonic GZ2000 or possibly also the new Sony Flagship a step backwards in that department.

Interesting that your C8 calibration almost completely eliminates the issue and I hope you get a chance to calibrate a G1 or C1 to understand whether that same fix is available.

Have you calibrated C9 or CX and did the calibration address luminance overshoot as effectively or is that ‘fix’ limited to C8 (in your experience)?

I pretty much never notice my C6 as a TV. Once-in-a-blue-moon near-black pans can expose done DSE and make me aware of the screen, but for the most part it’s invisible.

I’ve never experienced these luminance overshoots on content myself, but from the videos I’ve seen, I’m pretty concerned it’s the kind of screen anomaly I’m going to find very distracting and annoying (especially after your comments regarding viewing SDR on a GZ2000).

So I’m going to sit tight with my C6 until I get the all-clear on Luminance Overshoot from pros on the Forum like you...

(having to set up MadVR to perform custom dithering just so I can move up from 65” to a 77” screen seems almost worth it, but not quite...).

 

[dotnotbot]

Here's a good example to test for overshoot. Unfortunately no one answered me. I'm very curious how A90J performs.

2021 Sony Master Series A90J OLED Owner's Thread...

Anyone else near that 100hr mark with same or better results? So far it's like 3/3 !

www.avsforum.com

 

[jk82]

I’ve got a C6 that suffers from reduced bit-depth near-black, but never exhibits overshoot that I’ve noticed on content.

I've had a C6 too before the C8. I'm certain this luminance overshoot issue caused by the white sub-pixel didn't exist on 2016 models otherwise I would have noticed.
What I did notice though was the very poor near-black gradation which I sometimes even noticed on uhd blu-rays.

Interesting that your C8 calibration almost completely eliminates the issue and I hope you get a chance to calibrate a G1 or C1 to understand whether that same fix is available.
Have you calibrated C9 or CX and did the calibration address luminance overshoot as effectively or is that ‘fix’ limited to C8 (in your experience)?

I just have a i1Display Pro , not even a spectro. So I'm really only a hobby calibrator.
The near-black gamma curve of my C8 replacement panel is a complete mess. The 1DLUT requires heavy adjustments to get it right, I don't really know but maybe that has something to do with improving the overshoot issue...

I barely know anything about the C9 but when I skimmed through the CX threads I found some good video examples that look just as bad as it was on the C8 originally, before the dithering firmware fix. This playlist has some good examples:

https://www.youtube.com/playlist?list=PL2WYt1Qnmcq9BeCZrwGYgi5NVc49-R5RH

Also there's this article from John Archer:

LG Promises A Resolution For Latest OLED TV Luminance Overshoot Issue

Affected users may have to wait a while for this one, though

www.forbes.com

I find this whole situation a bit funny as it feels like 2018 is repeating.

So I’m going to sit tight with my C6 until I get the all-clear on Luminance Overshoot from pros on the Forum like you...

That's a diffcult decision, wait it out or take the risk.

These newer oled TV's have immensely better near-black handling which would be a major upgrade for you. The Panasonic GZ2000 was also better in that regard than my C8 but I just couldn't bear the overshoot and also some uniformity issues, so in the end I'm glad I got rid of it even though I miss the better near-black color accuracy and HDR performance...

Then there's also this new 'grid in bright scenes' issue that people keep talking about. I haven't seen this with my own eyes yet but I'm sure this would bother me a lot.

 

[Wizziwig]

I’ve got a C6 that suffers from reduced bit-depth near-black, but never exhibits overshoot that I’ve noticed on content.

I’ve never experienced these luminance overshoots on content myself, but from the videos I’ve seen, I’m pretty concerned it’s the kind of screen anomaly I’m going to find very distracting and annoying (especially after your comments regarding viewing SDR on a GZ2000).

So I’m going to sit tight with my C6 until I get the all-clear on Luminance Overshoot from pros on the Forum like you...

(having to set up MadVR to perform custom dithering just so I can move up from 65” to a 77” screen seems almost worth it, but not quite...).

The older OLEDs like your C6 were not immune to the issue. I first saw it on a C6 or E6. It's been so long I don't recall the exact model and content. Like you, I didn't see it under normal content watching. I discovered it when I paused some very dark content and then panned the image left/right. Very dark pixels on a black background left a brighter trail behind them. Sort of like you see in this video but on a much darker scene.

Anyone who thinks this only happens in games or low quality SDR, see this playlist (including Gemini Man 4K HDR samples). Edit: I see jk82 beat me to it.
Gamers just happen to be the most vocal complainers because their content focuses on constant camera panning - see the many posts and videos starting on page 499 of this thread.

 

[fafrd]

I've had a C6 too before the C8. I'm certain this luminance overshoot issue caused by the white sub-pixel didn't exist on 2016 models otherwise I would have noticed.
What I did notice though was the very poor near-black gradation which I sometimes even noticed on uhd blu-rays.

Yes, near-black gradation and linearity on the C6 was a mess. I got it dialed-in to a level I’m reasonably happy with doing unnatural acts...

I just have a i1Display Pro , not even a spectro. So I'm really only a hobby calibrator.

Me too (though I did pick up a used i1 Spectro).

The near-black gamma curve of my C8 replacement panel is a complete mess. The 1DLUT requires heavy adjustments to get it right, I don't really know but maybe that has something to do with improving the overshoot issue...

I’ve not had the joy of performing LUT-based calibration yet...

I barely know anything about the C9 but when I skimmed through the CX threads I found some good video examples that look just as bad as it was on the C8 originally, before the dithering firmware fix. This playlist has some good examples:

https://www.youtube.com/playlist?list=PL2WYt1Qnmcq9BeCZrwGYgi5NVc49-R5RH

Also there's this article from John Archer:

LG Promises A Resolution For Latest OLED TV Luminance Overshoot Issue

Affected users may have to wait a while for this one, though

www.forbes.com

I find this whole situation a bit funny as it feels like 2018 is repeating.



That's a diffcult decision, wait it out or take the risk.

These newer oled TV's have immensely better near-black handling which would be a major upgrade for you. The Panasonic GZ2000 was also better in that regard than my C8 but I just couldn't bear the overshoot and also some uniformity issues, so in the end I'm glad I got rid of it even though I miss the better near-black color accuracy and HDR performance...

As I said, I performed unnatural acts with my 21-point and got near-black to where I don’t think I’m leaving much but video-level 17 on the table. My near-black is essentially rotating between the colors so I end up with pretty good shadow detail and at those low luminance levels, you only notice luminance, so the changes in chrominance are essentially invisible.

I certainly wouldn’t trade my current near-black for anything that ever resulted in visible flashes on content.

So I’ll wait until LGD gets this sorted out...

Then there's also this new 'grid in bright scenes' issue that people keep talking about. I haven't seen this with my own eyes yet but I'm sure this would bother me a lot.

Yes, I’ve seen references to that. Great - one more thing to worry about.

If you ever gain any insight as to how the 1-D LUT calibration is reducing luminance overshoot in your C9, please report back.

 

[fafrd]

The older OLEDs like your C6 were not immune to the issue. I first saw it on a C6 or E6. It's been so long I don't recall the exact model and content. Like you, I didn't see it under normal content watching. I discovered it when I paused some very dark content and then panned the image left/right. Very dark pixels on a black background left a brighter trail behind them. Sort of like you see in this video but on a much darker scene.

Anyone who thinks this only happens in games or low quality SDR, see this playlist (including Gemini Man 4K HDR samples). Edit: I see jk82 beat me to it.
Gamers just happen to be the most vocal complainers because their content focuses on constant camera panning - see the many posts and videos starting on page 499 of this thread.

Now you’re putting me in a tough spot. I’m happy with my C6 and don’t want to go looking for an overshoot issue I haven’t noticed up to now - I won’t be able to Unser it.

But if my hunch is correct and those Rtings measurements are showing the same overshoot that underlies the luminance artifact people are seeing, you can go back to the C6, the EF9500, and even the EC9300 and see exactly the same waveforms - it appears to have been an intrinsic part of LGD’s WOLED since Day1:LG EC9300 OLED Review (55EC9300)

 

[jk82]

The older OLEDs like your C6 were not immune to the issue. I first saw it on a C6 or E6. It's been so long I don't recall the exact model and content. Like you, I didn't see it under normal content watching. I discovered it when I paused some very dark content and then panned the image left/right. Very dark pixels on a black background left a brighter trail behind them. Sort of like you see in this video but on a much darker scene.

I had the LG C6 for more than a year and I don't remember ever seeing anything like the overshoot that the newer oleds produce and I messed around with near-black scenes a lot, trying to improve shadow detail.... I think when I got the C8 I already noticed this the first day or so while playing with the brightness slider while looking at paused near-black scenes. Back then I thought this was just an anomaly with the brightness processing.
So if the 2016 oleds really already suffered from this, it must've been way less severe.

 

[Wizziwig]

I think it was definitely less severe. As I said, I never noticed it while just watching content. I stumbled upon it by accident while messing with the remote. Somehow got into LG's "Live Zoom" feature which allows you to freeze and then zoom and pan over any video. This was a very, very dark scene. Practically all black with only a few brighter just-above-black pixels that left brighter trails when panning. I didn't think much of it at the time. I thought maybe it was some bug with the Zoom feature itself. Only when the overshoot topic got all the press a few years back, did it occur to me that it was probably a related issue. If anyone with a 2016 or 2017 OLED really wants to investigate the history of this issue, I'm sure I can located the scene again. I have a flash drive full of movie and tv clips that I have used to test TVs for many years - it's bound to be on there. It's probably best left unseen if you're happy with your TV.

 

[hamad138]

Panasonic solution is the best and u barely see it. Apparently Sony copyd Panasonic .

The worst one is LG implementation since it causes noise and black crush

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