OLED size correlation to brightness / OLED uniformity variances

[speancer]

Hi there,

Would someone be a darling and try and explain in simple words, why is OLED size directly in correlation with its brightness, and if there are any hopes for this to change in the future? Each time I see a new OLED line coming out, 42 and 48 inch variants are always marked as less bright than 55+ inch counterparts. Why is that the smaller OLED pixels are unable to emit enough light to match the bigger ones? I was never good at physics

Recently I've tried the LG G3 55" OLED (as a PC monitor) that my friend borrowed me for the time of his vacation, and I was blown away by the overall difference in brightness. It just makes my LG C2 42" look bad and dim! Some HDR highlights were straight out blinding me! Smaller HDR highlights poped like crazy. Big bright scenes were visibly brighter and punchier. I was actually so much impressed by G3 that now I crave to get one as my new main display. The only problem is the size. I'd have to quite dramatically re-arrange my space to make the G3 viable as a PC monitor. Thus my question about size.

I was really disappointed with LG not equipping this year's C4 series with the Micro Lens Array bright booster (but yeah, they need the selling point for the G series). LG C4 42" is still not an upgrade significant enough over my C2... About 200 cd/m2 more in peak brightness is just not enough, where G3 is about TWICE as bright as my C2, delivering even 700-800 cd/m2 more peak brightness. It's also significantly brighter in big bright scenes, making high brightness scenes' HDR highlights much more pleasant and punchy (like the sun at noon against the bright sky in Horizon: Forbidden West), whereas my C2 would start to visibly dim itself already.

I found QD-OLED monitors also disappointing, in terms of brightness they do not even exceed my C2 in 10% window peak brightness (capping at about 450 cd/m2, while C2 is capable of 700+ cd/m2 in 10% window). They are capable of exceeding 1000 cd/m2 in very small highlights (2% window), but that's not not enough difference, and also the 1000-nit modes mess up EOTF tracking, according to the reviewers, so these monitors are better of being used with DisplayHDR 400 True Black mode anyway, otherwise yeah, you can get those 1000 cd/m2 peaks in 2% window, but it causes dimming of bright larger screen size scenes.

WOLED monitors seem to do better job at brightness presentation, but even the brightest models fall much short behind the LG G3. For example, ASUS XG27AQDMG is capable of 750 cd/m2 in 10% window (barely better than my C2) and over 1100 cd/m2 in 2% window, while G3 peaks at over 1400 cd/m2 for 2% and 10% window test samples.

Overall, how long do you think it will take for smaller OLED sizes (42, 48 inch) to be able to get significantly brighter so that upgrading over my LG C2 would have enough punch to line up with the amazing picture delivery of the LG G3? I would buy the LG G3 55" immediately if it wasn't for the space re-arranging issue to use it as a monitor (since G4 is just slightly brighter and over twice as expensive where I live, as always with the newer models). Would you get the G3/G4 now, or would you wait for 2025 OLED line-ups (if money wasn't any issue, but size was).

[speancer]

Really, no one knows? I'm disappointed with this forum. Anyway, I decided to switch to LG G4 55" as my PC monitor from a proper distance, and it blew my C2 42" out of the water, amazing difference.

[jorimt]

Really, no one knows? I'm disappointed with this forum. Anyway, I decided to switch to LG G4 55" as my PC monitor from a proper distance, and it blew my C2 42" out of the water, amazing difference.

Short answer is the smaller OLED panels' pixels are too small, dense, and close together for them to match the brightness of their larger counterparts without introducing issues such as overheating and decreased life-span of the panel.

Since it's mostly a physical limitation for this panel type at these resolutions, I doubt there will be a viable solution any time soon, beyond switching to a larger OLED (which you've already done).

[speancer]

Oh, hello jorimt, thank you for your reply. I reckon you remember me? It's been a while. You helped me a lot with learning/understating about G-SYNC, and more.

Yes, after some consideration I've re-arranged my room and turned it into the real dream PC Master Race gaming station, with my brand-new 55-inch LG G4 OLED being the cherry on top, powered by RTX 4090. Not gonna lie, I'm waiting for 5090 as well to re-play games like Alan Wake 2, which destroys 4090 without DLSS and FG. RTX 5090 will surely help to mitigate VRR gamma flicker issues also, as it'll allow me to lock my frames at higher numbers at steady framerate. I just took your advice and I lock my frames in RTSS at the level of them being as constant as possible, cuz as you know fps fluctuations result in OLED VRR gamma flickering.

So basically I made a good decision for my use case then? If you say waiting for smaller OLEDs to match 1500+ nits brightness is rather pointless, at least currently.

Let me add that LG tried to be smart with their newer OLEDs (this includes all models which got WebOS 23 update) and they actually locked access to the vital options in the service menu (as most OLED enthusiast know, disabling TPC and GSR in service menu is just mandatory for a PC monitor use case). Fortunately, using LGTV Companion software and writing a few commands in Windows' command prompt fixes the issue and re-opens full access to service menu vital options

Is there a "long answer" to my question?
Could it be possible to, maybe, use larger heatsinks into smaller screens to achieve the same effect?
Do you think LG C-series TV could actually achieve G-series brightness, if it was equipped with MLA gen2 tech and a heatsink?

[jorimt]

I reckon you remember me? It's been a while.

Yup.

So basically I made a good decision for my use case then?

If you want maximum possible peak HDR brightness, yeah.

The 48C4 is enough for me since it fits my space and I still mostly game in SDR. I primarily reserve HDR for offsetting the brightness loss with CRT filters/BFI via my RetroTINK 4k + retro consoles.

Don't get me wrong, HDR is great for movies, but it's all over the place in gaming, especially on PC. And then there's the whole lack of clarity in what is the actual "correct" HDR settings per display/game is (hint: there never seems to be one); hopefully it standardizes sooner than later.

Let me add that LG tried to be smart with their newer OLEDs (this includes all models which got WebOS 23 update) and they actually locked access to the vital options in the service menu (as most OLED enthusiast know, disabling TPC and GSR in service menu is just mandatory for a PC monitor use case).

Yeah. I noticed. Fortunately, I don't seem to be getting active dimming with all the care features disabled, only when the screen is idle, so it seems they tweaked it well enough, but it is too bad they made it so difficult to access the full service menu.

Is there a "long answer" to my question?
Could it be possible to, maybe, use larger heatsinks into smaller screens to achieve the same effect?

I think it's the size and closeness of the pixels that's the main issue, even if it had a heatsink, else I assume they'd make a 42" G4. I know there are sources that go into more detail, just can't recall them off-hand.

HDTVTest has more on it in some of his videos:
https://www.youtube.com/@hdtvtest/searc ... =42%20inch

Do you think LG C-series TV could actually achieve G-series brightness, if it was equipped with MLA gen2 tech and a heatsink?

Since the G-series has effectively the same panel as the C-series, just with an MLA layer and a heatsink, yeah, but then they'd be identical, so the different model tiers and price structures would become a bit of a moot point in that case.

[speancer]

Don't get me wrong, HDR is great for movies, but it's all over the place in gaming, especially on PC. And then there's the whole lack of clarity in what is the actual "correct" HDR settings per display/game is (hint: there never seems to be one); hopefully it standardizes sooner than later.

Funny, I have exactly the opposite experience and no trouble with HDR settings in games. I find a lot of movies to be mastered poorly in terms of HDR, not really making good use of HDR effects, also the black level floor is an issue with almost all movies and shows that I watch, like 9 in 10 of them have raised blacks. It really annoys me that so many filmmakers still make an "artistic choice" to have raised blacks in their work. There are some movies which look great and have incredible HDR highlights (despite the usual raised blacks), but at the same time there are many movies and shows that use HDR goodness really poorly, even when mastered in Dolby Vision. PC gaming with HDR, for the most part, is absolutely incredible in my experience, games seem to take full advantage of HDR effects, and it' much rarer to see raised blacks in games, true black OLED goodness is more common in gaming. These days it's even easier to enjoy HDR in gaming thanks to NVIDIA RTX HDR filter, which uses artificial intelligence to convert SDR to HDR in games, and it works really good, both to my eyes and in testing (I really like GamingTech channel for HDR tests in games, the author also covered RTX HDR and found out that it actually can do even better job than native HDR, especially in terms of black level floor). Many newer games work flawlessly with HDR, automatically loading HDR calibration profile and setting peak luminance accordingly. Older games (and newer games with no native HDR) can now look amazing either thanks to auto HDR function in Windows 11 or RTX HDR. I'm myself an HDR and picture quality junkie, so RTX HDR was kind of ground-breaking option for me. Now every game can be an HDR game

Yeah. I noticed. Fortunately, I don't seem to be getting active dimming with all the care features disabled, only when the screen is idle, so it seems they tweaked it well enough, but it is too bad they made it so difficult to access the full service menu.

Oh, it's not difficult at all. It's really easy, that was my point. Like I said, all you need is LGTV Companion software installed on your PC and then you literally copy-paste four lines of commands in command prompt and it's fully unlocked again! I had to disable TPC and GSR for my G4, static dimming was way too invasive for a PC monitor use.

I think it's the size and closeness of the pixels that's the main issue, even if it had a heatsink, else I assume they'd make a 42" G4. I know there are sources that go into more detail, just can't recall them off-hand.

So I assume the cause is simply just that it's harder to dissipate heat accumulated on a smaller surface.

Since the G-series has effectively the same panel as the C-series, just with an MLA layer and a heatsink, yeah, but then they'd be identical, so the different model tiers and price structures would become a bit of a moot point in that case.

Of course I understand that. The reason why I asked is that LG could, possibly, release something like C5 that would be bright enough to match, or at least be close to catching up in performance with current G series, despite its smaller size. So you say it's possible and the smaller size (42, 48) wouldn't be a problem then? Or even then the hypothetical LG 42C5 would not be as bright as previous gen G series?

[jorimt]

Funny, I have exactly the opposite experience and no trouble with HDR settings in games.

I'm an artistic intent/accuracy nut to an extent (I still calibrate SDR to 100 nits, for instance), so if the black floor is intended to be raised in certain HDR movies, I take it as it is, but yeah, there are certainly many poor HDR movie conversions.

Even so, I still find HDR in the gaming space infuriatingly inconsistent where a set standard is concerned; labeling the setting things like "Paper white," and then internally changing the offsets and definitions of the parameters per game instead of just making it clear which the peak nit and black floor sliders are makes it difficult to confirm if and when you're getting the optimal balance of highlight detail and brightness output per title, and even when you rely on the community to tell you (be it forums or YouTube videos), beyond using HGIG, what to set the sliders to per games (especially on PC) ultimately boils down to subjective opinions and/or is very display model dependent.

But yes, if all you're looking for is maximum brightness output, I'm sure HDR gaming is a lot easier to deal with.

Oh, it's not difficult at all. It's really easy, that was my point. Like I said, all you need is LGTV Companion software installed on your PC and then you literally copy-paste four lines of commands in command prompt and it's fully unlocked again! I had to disable TPC and GSR for my G4, static dimming was way too invasive for a PC monitor use.

I mean difficult for the layman who has acquired a service remote after reading a reddit thread, but yeah, good to know. I'll attempt that method if I ever feel like I need to access those setting though (have yet to even formally calibrate mine; waiting for more hours on it).

So I assume the cause is simply just that it's harder to dissipate heat accumulated on a smaller surface.

Essentially. Again, the pixel pitch is a lot smaller on the 42" especially.

So you say it's possible and the smaller size (42, 48) wouldn't be a problem then? Or even then the hypothetical LG 42C5 would not be as bright as previous gen G series?

Oh, no, I was referring to the 55"+ C-series. I still think it would be an issues for the 48" and under. Again, if they could easily release a 42" G4, I have no doubt they would have by now, since there's certainly enough demand for it.

[speancer]

I'm an artistic intent/accuracy nut to an extent (I still calibrate SDR to 100 nits, for instance), so if the black floor is intended to be raised in certain HDR movies, I take it as it is, but yeah, there are certainly many poor HDR movie conversions.

Even so, I still find HDR in the gaming space infuriatingly inconsistent where a set standard is concerned; labeling the setting things like "Paper white," and then internally changing the offsets and definitions of the parameters per game instead of just making it clear which the peak nit and black floor sliders are makes it difficult to confirm if and when you're getting the optimal balance of highlight detail and brightness output per title, and even when you rely on the community to tell you (be it forums or YouTube videos), beyond using HGIG, what to set the sliders to per games (especially on PC) ultimately boils down to subjective opinions and/or is very display model dependent.

Ah, I see what you mean. Yes, with that I agree and I have stumbled upon misleading in-game HDR calibration settings. Anyway, I don't think the state of HDR gaming on PC is that bad and it seems to be improving. Like I said, for me it's games that actually do better job at displaying amazing HDR effects across the screen, while movies quite often tend to disappoint.

I mean difficult for the layman who has acquired a service remote after reading a reddit thread, but yeah, good to know. I'll attempt that method if I ever feel like I need to access those setting though (have yet to even formally calibrate mine; waiting for more hours on it).

If you decide to do this, or whoever interested who reads this wants to do this, here's how:

1. Download LGTV Companion software and install it on your PC (and either use the scanning option or add your TV data manually)
2. Make sure your LG OLED TV is in the same network as your computer
3. Agree when TV prompt asks for connection (which LGTV Companion will attempt)
4. Open command prompt as administrator and use the following lines (sometimes you have to do the first two lines a few times before it works, you'll know when you see a confirmation of successful action):

cd /d c:\Program Files\LGTV Companion
lgtvcli.exe -settings_other "{\"svcMenuFlag\": false}"

cd /d c:\Program Files\LGTV Companion
"LGTV Companion.exe" -button IN_START

Now use your service remote (or any other way to access service menu) by pressing InStart button, enter 0413 pass code, and voilà, full access service menu will appear. To reverse the process, simply use the same command but put "true" instead of "false" or perform a full TV reset (note that changes you've made in the service menu persist even after resetting or disabling full access to service menu).

Oh, no, I was referring to the 55"+ C-series. I still think it would be an issues for the 48" and under. Again, if they could easily release a 42" G4, I have no doubt they would have by now, since there's certainly enough demand for it.

I see, makes sense. I really wanted LG to deliver a 42-inch G series specimen, but after using my 55-inch G4 I don't even wanna go smaller anymore, it's awesome for the real immersion and movie watching. Then I am confident to say I made the right choice upgrading to G series. I'll probably just stick to G series, just like I'm sticking to RTX X90 graphics cards.

[jorimt]

If you decide to do this, or whoever interested who reads this wants to do this, here's how:

1. Download LGTV Companion software and install it on your PC (and either use the scanning option or add your TV data manually)
2. Make sure your LG OLED TV is in the same network as your computer
3. Agree when TV prompt asks for connection (which LGTV Companion will attempt)
4. Open command prompt as administrator and use the following lines (sometimes you have to do the first two lines a few times before it works, you'll know when you see a confirmation of successful action):

cd /d c:\Program Files\LGTV Companion
lgtvcli.exe -settings_other "{\"svcMenuFlag\": false}"

cd /d c:\Program Files\LGTV Companion
"LGTV Companion.exe" -button IN_START

Now use your service remote (or any other way to access service menu) by pressing InStart button, enter 0413 pass code, and voilà, full access service menu will appear. To reverse the process, simply use the same command but put "true" instead of "false" or perform a full TV reset (note that changes you've made in the service menu persist even after resetting or disabling full access to service menu).

Good to know.

[speancer]

I mean difficult for the layman who has acquired a service remote after reading a reddit thread, but yeah, good to know. I'll attempt that method if I ever feel like I need to access those setting though (have yet to even formally calibrate mine; waiting for more hours on it).

I've heard that OLEDs need to "break in". Is that really a thing?

I've been considering taking some action against my G4. I am quite unhappy with full white and grey scale uniformity... I don't know if that's something that could improve overtime or not. There were some lines visible on grey, but they went away after a pixel refresh cycle (it was the same with my C2).

Discoloration on full grey persists. It's like it's brighter and lighter grey from the bottom left corner to upper left corner, and on the other side it's darker and reddish.

Discoloration on full white field is slightly reddish on the sides, and slightly bluish in the centre.

Did I get a bad panel? I mean, G4 is expensive and the top model, I'd expect perfection from a high-end LG display.