Why 24fps is not enough for HDR movies

[lors]

Yeah it is HDMI VRR. It's a TV, no Gsync-module, but Gsync-compatible via HDMI VRR.

[Ben Ong]

Hi,

I saw that you are saying Dolby Vision IQ was implemented in C9, may i know which function is that? does c9 has ambient light sensor?

We don't have access to an LG C9 at this time but as far as I recall it's part of the "AI Brightness" system.

Most mid-range and high-end TV from the past 10-15 years has a built-in ambient light sensor. In the past, it's been used for SDR. The new development is that it's now used for HDR, too. The next step (for future TVs) will be more advanced sensors (and multiple sensors) that can also determine ambient "color temperature" and more.

i see, i was worried that this AI Brightness will screw up the Picture Quality so i leave it off. But i dont think in Dolby Vision mode, we are able to switch on the AI Brightness.

[Rasmus Larsen]

Yeah it is HDMI VRR. It's a TV, no Gsync-module, but Gsync-compatible via HDMI VRR.

Thanks. I will clarify the paragraph on VRR in the review.

[Rasmus Larsen]

i see, i was worried that this AI Brightness will screw up the Picture Quality so i leave it off. But i dont think in Dolby Vision mode, we are able to switch on the AI Brightness.

Perhaps just the ambient sensor then.

LG's engineers talked about the implementation back in the spring of 2019. Like the 2020 models, the 2019 models use an LG-developed system for SDR, PQ and HLG whereas Dolby Vision relies on Dolby's system. So I asked them about what has changed in the 2020 models and they confirmed that it's the same implementation - now with an official name.

[Rasmus Larsen]

Also worth noting that we got LG CX to decode an AV1 video clip - although a low-res version since that was all we had available at this time.

LG has confirmed AV1 hardware decoding support for the 8K models only but it would appear that the 4K models also have some level of support (at least CX).

[RGNY]

I just received the LG CX 65" and I'd like to calibrate it for optimal viewing. I've never done this before. What do you recommend?

[Icaras]

Sorry if this has been answered elsewhere, but when is the 48” scheduled to come out in the US?

[Rasmus Larsen]

RGBY: See our suggested calibration settings in the measurement section of the review. Remember that picture settings can be set individually for each input/source (HDMI1, HDMI2 etc.).

Icaras: It’s scheduled for late May but I think June is more plausible due to the coronavirus situation.

[LauraGómezLópez]

I made the decision of getting a CX instead of a C9 for 600 dollars more, based on this review and its statement about the eARC issues being solved out of the box without the need of updates.

The CX does NOT pass uncompressed, multichannel LPCM (5.1 nor 7.1 PCM) through eARC.

The following statement is misleading and almost deceiving, seeing as the CX model is still limited to 2.0 channels of PCM: "LG has also promised to fix the eARC issue (PCM being limited to 2.0 channels) affecting 2019 models. 2020 models come with the fix at launch while 2019 models will receive a firmware update sometime this year."

I kindly request that your review is updated.

[LauraGómezLópez]

Could you confirm whether the TV does or doesn't support 4K @ 120Hz over HDMI 2.0 by using 4:2:0 chroma subsampling on the PC, like Samsung does? An LG representative (Neil Robinson, senior director, strategic projects, LG USA) said in an interview, that the CX would support 4K@120Hz over HDMI 2.0, while the C9 would only ever support it over HDMI 2.1.

4k120 does work. The HDMI 4 input is the only input that allows 4k 120 fps over HDMI 2.0 though. And like you stated, it is limited to 4:2:0 or RGB limited, but it does work.

It's probably worth noting something strange that happens while using 4k120 though: there is a couple of pixels on all four sides of the image that don't make it into the frame; this is NOT an overscan issue (it's not about making sure that the "just scan" option in the aspect ratio setting of the image config is turned on): it's only maybe 3 to 4 pixels on every side of the screen. It's barely noticeable, but it is consistent.

[pierre2592]

Hello to you all, thanks for your review.
I'd like to know if the static content dimming issue is still present on this model?
I mean by that, does it still dim the whole picture when there's a static content such as game HUD or sport score board even when the Logo Luminance Adjustment is switched to "off" ?
Thank you !

[Tepii]

Just wanting a comformation that it is like I think the matter is of not beeing full bandwith hdmi 2.1 in CX than it was in C9. There is lot of information in the internet media about this, and yes LG has confirmed that it is true. But i feel it has been overly thought problem, because you only need 48 Gbit full bandwith for 12-bit, panels are 10-bit so it is irrelevant. There is no need for the full bandwith with these tv:s, nor the C9 or the CX. Someone even said it might be issue for pc gaming with powerful hardware, but i feel hdmi is standard so is 4k120HZ and chroma subsampling etc.. no matter how powerfull your system is it does not produce anything more than the standard allows. Yeah it is weird they limited that, cant think any cost save for limiting that bandwith, that would only real reason to that kind of move, despite it not making any real world meaning if it is 40 or 48 Gbit/s

[FreddellMeister]

Thanks for reviewing the Panasonic HZ1000 OLED. In terms of comparison with CX, which TV is better "calibrated" out of the box or after your published tweeks?
Is motion and near black detail any different?

[Vraman]

Great review, but there was no detail on the omission of DTS(Any format of DTS including DTS-X) in LG CX. Many of us who have ripped their 4K Blu-ray collections and play it through our NAS or separate hard drives connected to the TV's usb port will have an impact I guess. I don't have an AV receiver but Samsung's Ambeo soundbar and Sony's HW700DS for night time play. I'm sure like myself many prefer only DTS output over Dolby. If DTS isn't supported by LG CX but we want to play the DTS track from our ripped blurays, is there a solution ? Or do I have to get a C9 or a Panasonic/Sony ?

[Rachon34]

Hi there, it looks like the CX brightness is a bit down compared to the C9, would it affect the movie hdr experience? Thanks