Standard sdr  peak brightness for dark room  only need 100nits. From bright room, you can increase the brightness suit your environment.  I  use auto brightness setting to let tv automatic  adjust  brightness .

Use OFF , scale down OLED LIGHT to around 40 for SDR .
Peak luminance controls the amount of light from the white-boosting subpixel .

Typically with peak brightness ON , you should get a range of 0 to 330~400 nits from 0-100 [OLED LIGHT] in SDR .
OFF , you still get  around 0- 250 nits  , more than enough for everything in SDR .

If the peak brightness setting is on , it will typically hit 100 nits at 20-30 .

If you leave the peak brightness setting off , the range of luminance will be decreased so 100 nits will likely land at around 40-50.

100 cd/m2 is what the typical SDR TV shows are mastered at , 120 cd/m2 if you want a little bit more highlights and pops .

On = max of around 400 cd/m2
Off = max of around 250 cd/m2

Low / High = somewhere between 250-400.
Who is this " everyone " you speak of ? And how do you know which TV model they are using ?  B9 ? C8 ? C9 or CX ?

I am not saying you should definitely be using the exact same setting . Obviously you also have to consider the factor of panel variance here .
The C8 used to be able to hit 400 cd/m2 in SDR mode but a patch landed last year cutting down the peak brightness in SDR to around 300 cd/m2 .
B9 is quite a bit dimmer than C9 and CX as well. 

My C8 is calibrated to 100 cd/m2 at 32 OLED lights , I don't have a C9 but I have calibrated one at around the same number too [Peak off].
It is what it is , I don't measure peak brightness in SDR mode either .
If you are that obsessed with hitting the exact number you should be getting a colorimeter then .
Without that , the best you can do is only from estimation . Else , the range of 20-40 should be working fine for most people .
The peak brightness setting is unnecessary for SDR mode anyway , since SDR content is only using the colors within the rec.709.
The OLEDs should be more than capable of covering the color space of rec.709.

Not sure for C8, but C9 definitely on. LG had did a great job on Dynamic Tone Mapping for HDR.

I believe C8 also did great on that, it is just 2 years ago product which still pretty new.

They is two thing, one is Dynamic Contrast where i am off.
For Dynamic Tone Mapping setting I will re-check again but I am pretty sure I never face over expose the mid highlight of the image before.

So no need care on the DTM as it is disable in preset we choose.

Maybe disable is OFF,  maybe is ON, maybe is N/A. Haha!

I just check now it can, probably some changes is make after firmware update.

But in Dolby Vision mode, Dynamic Tone Mapping setting is not there.

Just use the thing best suite you, they is nothing correct or wrong, it is user preference.

I don't see any crush mid range highlight, it was the best setting for me and I already watch like that few months.

B9 had inaccurate setting by default, probably it impact the output which probably not only did by DTM but others setting as well.

From this article now I know why this feature is not there for Dolby Vision because Dolby Vision already have it owned Dynamic Tone Mapping.

I find it work perfectly, so I am going to stick to On in HDR10.
It make the HDR10 very closed to what Dolby Vision did which is much better. So far I had no complain on all movies I see.

https://www.rtings.com/tv/reviews/lg/cx-oled/settings

I read somewhere that DTM in HDR10 is equivalent to Dolby Vision. I think I just let it ON.

Most the time I watch in normal lighting condition room, but sometimes I watch in total dark room also.

I never ever facing over exposure issue at all.

Did you make some changes on the setting? suggest you reset back all to original and check again by turning on the DTM only.

Last time, someone here told me OLED Light, Contrast and Brightness cannot simply touch as this will impact the output.
I let all this in default setting and it looks just nice in Cinema Mode for all except Home Cinema Mode for Dolby Vision to me.

What does that mean? Overblown images?

This is also true. But not all models have hgig. Only 9 series and X series.

There was a time when the 7 or 8 series GAME HDR mode was so dim its unplayable on dark scenes. DTM helps to elevate this issue abit. Some even resort to dynamic contrast.

It also depends on game, as some game doesn't have control for white point, hgig can't help without it. But most of the newer games has it so its a moot point. The game on my head right is God of War and HZD, hgig might clip details on this 2 games.

I think the first game to implement this was COD modern warfare.
I haven't try ghost yet, but I'm glad they are implementing hgig.
And yes, alot of ps4 games didnt implement HDR correctly. Think alot of dev is still experimenting on HDR since it still quite new and haven't reach mainstream yet.
The worst I came across was monster hunter world before expansion.

Let's hope HGIG or HDR gaming as a whole mature in coming time for Ps5

Ok, I had listen to you guy and did some changes to my LG C9 setting with some reference from rtings.com Haha!

Actually previously I on the Dynamic Tone Mapping due to I find HDR is too dark.

Now I did some changes and yes it is better than before.

• Color Temperature - Warm 2
  
• Dynamic Contrast - Medium (this is recommended setting by rtings if you find HDR too dark), for SDR, this setting remain off.
  
• Dynamic Tone Mapping - Off
  

So actually Dynamic contrast is better than DTM?

I read comment from Internet, the auto was actually call Normal previously, LG should not change to call auto as it is misleading, it won't change the color gamut even different source of BT. 709 or BT. 2020 is detect, it remain same. For wide one is using back the native panel color gamut and ignore the preset. As for extended, I find the output a bit like increasing color.

I believe this is due to changing format in between SDR and HDR,  it had nothing to do with color gamut setting.

You put auto, extended or wide will give you same result also.

I think you misunderstand me. I never said Extended or Wide is correct color gamut but goes above is correct as this two color gamut had much wider color coverage.

I mean the Auto Color Gamut label is misleading as it didn't auto switch to different color gamut, it remain the same normal color gamut nonmatter what format it detect, either SDR or HDR.

sifu ssjben kena banned 30days i think

I already found what I want for HDR but the SDR still very wrong.
I find the SDR - isf Expert (Bright Room) is very wrong, the color is totally over blown.

So I decide to experiment again. Haha!

This time I also tune down a bit of sharpness from 25 to 22 as I am over did last time. Also De-Judder reduce to 3.
Finally I am sticking to Warm2, Color Gamut as Auto for SDR, HDR10 & HLG HDR. For Dolby Vision the value is Wide and cannot be change.

Dynamic Tone Mapping wise I decide left default On for HDR and Default Off for Dynamic Contrast as this give me black crush issue. 
Dynamic Tone Mapping make HDR brighter and frank speak I keep comparing On and Off, this value On never have over exposure issue at all.

Now I believe this is my Final Setting, I am complete experiment and decide on what SDR and HDR setting on my LG C9.

Hi,  To me 10 is way too soft in my distance viewing.
I don't find any issue as you mentioned in value 22 but it do happened after 22 especially on the value 25 I set previously.

They is two default value. 20 is default value for Cinema Home and Standard.

I don't insist of default value? Just getting the one suite.

I am testing the value one by one last few days until I satisfied, that why you see my color for SDR is 57, not 55, 60 and so on.

Also my Sharpness is 22 not 20, 25 and so on.

If you can find it alot cheaper than c9 then yes. But if diff is around 1k I would go for c9.

I have a b6, tried a b9 before changing it to c9.

I can tell that the b9 has been cut down alot compare to my old b6. The brightness is lower than my b6 by a margin. The color accuracy by default is way off too.

The older B series doesn't feel like it's a water down oled, in fact it feel premium, but b9 felt to me like more of a mid range TV.

Still it's an oled and it's good. Just that the pricing is too near to c9 now. It use to have a big gap on the price thou.

Just want to update. Im getting proper signal using ugreen 8k cable.
This is C9 + ugreen 2.1 cable ya.
@SSJBen