Pls Help Test Z9X with Oppo 203

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No not at all.

As I said earlier, it's worth you guys reading up on it - here's a good place to start:

https://professionalsupport.dolby.c...and-can-I-convert-between-them?language=en_US

And

https://professionalsupport.dolby.com/s/article/Dolby-Vision-Metadata-Levels?language=en_US

 

Nice, thanks. That is very interesting. Dolby Vision has so much that goes into it.

 

The first link talks about needing to use the correct backwards compatibility algorithm for showing v2.9 on a 4.0 (assuming I read this right). Is it possible the C9 algorithm is brightening the picture?

 

No, this is simply talking about creating CMv2.9 metadata in post if you're doing a CMv4 grade so that the deliverable is backwards compatible with CMv2.9.

 

I made a test last night and took some shots with my phone.

You can see the difference. Left is played by c9 internal player while right is by z9x pro. TV is on the dolby vision cinema home mode for both images.It looks like c9 image is brighter. Then I came up with a guess I need Mark to help confirm. Is it possible that the max nits used by LG C9 internal player is different from that in the EDID transmitted through HDMI? I saw the reviews of LG C9 on ratings.com and from some other places stating the peak brightness is around 850 nits.

I uploaded my edid file. @Markswift2003, can you edit the dv max nits to 750,800,850 for me so I can test if what I guess is really the reason behind all this.

 

Perhaps the C9 is using a lower nit tine curve, meaning that the TV is using less tone mapping and making the overall image brighter? Like a 1k nit tone curve vs a 4k nit tone curve.

Also, what if you use the normal cinema mode? Do you still see a visual differencr? Cinema home has different EOTF tracking I'm pretty sure. Maybe it's doing some sort of dynamic tone mapping. Curious to see what normal cinema mode does.

 

I turned all LG processing stuffs off including dynamic tone mapping and ai brightness when I did the test. I did try dolby vision cinema mode and the image was dimmer than in cinema home but I didn't do the compare between the c9 and z9x pro. I think I can give it a try later tonight.

 

Yea lemme know! Cinema mode (not home) is considered the most "accurate" DV picture mode.

 

I assume the internal player wouldn't need to use the EDID because it's written for the TV.

TMaxPQ which is what you're referring to is 700nits for the C9. All this means is that the panel is capable of 700nits and so any HDR signal (Dolby or otherwise) will be tone mapped down to 700 if necessary, and it's only necessary for specular highlights in content that exceeds 700nits which would be rarely seen. So the vast majority of content will never need to be tone mapped.

DV Version: 1 [short 12-byte version]
DV DM Version: reserved
DV Interface: standard and low latency 422 12bit
2160p60: supported
YUV422 12bit: not supported
Global Dimming: not supported
Backlight Control: not supported
RED Primary: 0.707, 0.293
GREEN Primary: 0.172, 0.797
BLUE Primary: 0.133, 0.047
MAX/MIN Luminance: 700 / 0.000 nits

Of course, because of the nature of PQ -Perceptual Quantiser (I hate when people abbreviate "Picture Quality" to "PQ"!!) content heading towards 700nits is rolled off so it all fits in the gamma, but that doesn't matter because that's how PQ works as opposed to Power Gamma used in SDR.

So yeah, there could be a difference, and seemingly is, in the way that PQ is handled by the internal player vs external sources but I would absolutely trust the external sources to get it right. This is borne out by comparing multiple external sources - in my experience, every external DV source I've tried from STBs, including Zidoo, to UHD BluRay players all produce pretty much the same picture. If the C9 player is different then that tells you something.

Not to say you shouldn't use it. If you think the picture looks better then who am I to tell you you're wrong. Some people like 60Hz which I find horrific, some people like motion enhancement which I find equally horrific, but if that's what they prefer, that's what they prefer.

But I believe the Zidoo gets it right within the constraints that bind it with regards to the lack of FEL.

Increasing TMaxPQ to 750, 800, 850 nits will only make things worse because the tone map would be to those values which your panel cannot reach, so you'd keep specular highlights at the top end but APL would be reduced, although in reality you probably wouldn't notice any difference at all.

You should get a brighter but less accurately tone mapped image using noticably lower values of TMaxPQ. This would lose specular highlights at the expense of brightness which is possibly what the internal player is doing.

Because the C9 Primaries are as near as dammit to BT.2020, you can try the attached EDIDs if you like, ranging from 10 to 10,000 nits. They are LLDV but will allow you to see what happens.

 

Thank you for the explanation. Although I don't quite understand those things that happen behind the scene but I believe what you said. I'll do some more test with the edid you give. Here comes the subjective part of what I am doing this for. Like B0RN like his oppo image I really like my c9 image. I kind of feel it's more popping and living. If somehow I can make Zidoo do the same thing I wouldn't have to switch back and forth any more.

EDIT: When you say "They are LLDV", do you mean I can only use them when I set Player-Led DV on my Zidoo? @Markswift2003

 

Those EDIDs only support Player Led DV and not TV Led, so if you load them into the Zidoo you won't get TV Led DV out of it - as I say, for a quick test to see the results it doesn't matter.

If by chance you hit a value you like the look of I can always change your own EDID to match it and include TV Led DV.

 

Both Cinema and Cinema Home modes are fine to use to per rtings.com - And should not make a difference when we are testing both devices on the same picture mode.
I am testing a lot of things directly on the C9 and its like a veil is lifted off of the tv set! It even leaves Oppo behind in many cases. Its a bit of a chore to convert files to TS to play on the C9 but I think that is what I am going to start doing and use C9 where I can afford to (IE, streaming content that doesn't have TrueHD audio etc.)

PS, funny enough I was also checking out Alita in DV the other day and found the same case as you, C9 pic was more vibrant and richer. If you wanna have your mind blown, check out Avatar 1 and 2 in DV on C9 (with Reset999's RPUs plugged in) I talk to him pretty much every day

 

I just tried your edid but it didn't seem to make any difference whether I use 100nit or 1000nit, Is it because the z9x pro I'm using is somehow different?

 

No not at all. It probably means the content doesn't need much tone mapping, although I would expect a difference in highlights between 100 and 1000 but often these things don't show very obviously unless you use test patterns or have something with peak content and you know what to look for.

 

I just tried the cinema mode and the difference is quite the same. Image is kind of brighter played by c9 than by z9x pro.
The screenshots I took with my phone actually doesn't mean anything except for indicating a difference.

 

You don't say which is which but from those pictures the second one looks better tone mapped - less blown in the highlights, but obviously that could easily be just the camera.

 

So I'm out of sorts now. I probably have got used to the image produced by c9 and stuck on it. Got any advice that you can think of?

 

Watch a movie instead of worrying about it

 

yea

 

How are you delivering your media to Zidoo and other devices in the long term?