topic Re: Actual nits in Archive

Actual nits

Unarmedberetta — Sun, 13 Feb 2022 18:47:58 GMT

Hi all.

Sorry to keep raising my findings. I just hope sky read this board and provide either a solution or a announcement as to why.

Now I do have a lux meter to measure light. With the settings I'm using I'm only getting a peak of 485 nits on a 10 percent window. This was even with video and backlight on 100 to try and get the highest rating possible. Most content ranged between 300 and - 420.

Slightly off the 620 described by sky and lower than Tom the tech chap on YouTube. However does line up with some third party reviews.

Now hear me out on this.

I feel like Tom and a few of the YouTubers got there unit earlier. Hence the higher nits and before the flicking fix. I'm thinking the flicking fix raised the black level to stop the LEDs and local dimming from working properly and also lowered the peak brightness level resulting in these lower ratings.

Where some of the bigger company's might have reviewed there versions later with the patch applied.

Don't suppose anyone managed to measure there peak brightness plus a local dimming test when the TV first came out?

Re: Actual nits

Jayboy1990 — Sun, 13 Feb 2022 19:06:39 GMT

I am planning on locating your posts with all the various findings re. Image quality and image features that don't seem to be working and posting them to sky seperately tomorrow and hope they can get back to us with some confirmation as to what's happened.

This isn't something the community has information on as it's very technical and would need investigation internally with specialised teams I imagine.

I shall try and take the fight further and report back if I hear anything. @Unarmedberetta

Re: Actual nits

joemit — Sun, 13 Feb 2022 19:33:50 GMT

Thanks @Unarmedberetta for raising this, I would be VERY interested to see an informed response to this...

Re: Actual nits

Unarmedberetta — Sun, 13 Feb 2022 19:48:56 GMT

I've attempted to raise with this sky. However I come from a technical background and have worked with TVs in the past.

It's clear local dimming isn't working to it's full extent and it needs to be looked into. I've attempted to raise this directly with sky and the agent I spoke to was very honest. Her exposer was around 16 hours and half of that was just looking at the TV. There customer service reps and not TV techs. (not there fault at all) agent even tried to see if anyone else had raised it internal and the only thing close was that local dimming toggle does nothing (it does but only on HDR content and it's really not noticeable.

Due to light leaking from the speaker zones I have predicted that there's around 62 dimming zones on the 55 inch model which should allow for decent local dimming performance. However I could have overguestimated but without local dimming doing as it should I can't use the tests to find out it's true count.

If you could raise this I would certainly hope for a explanation. I'm not trying to be a pain I just want to know what's happening. As otherwise I can only think the worse and thats they have pushed the panel to far at factory and have now lowered voltage in a attempt to rectify the issue.

Re: Actual nits

Godfrey — Sun, 13 Feb 2022 20:43:24 GMT

@tarbat made an interesting comment, way back on 11th November at 03:45 pm, with respect to the peak luminance ability of the glass panel............

"And despite their production guidelines saying that they'll conform HDR10(PQ) content to HLG at 1000cd/m2, they decide to manufacture a TV with peak luminance of around half that value. Crazy?

Maybe Sky should grade their HLG content on a Sky Glass TV to ensure optimum picture quality on Sky Glass "

Godfrey.

Re: Actual nits

Unarmedberetta — Sun, 13 Feb 2022 20:47:33 GMT

That comment isnt exactly true.

It's mentioned by people that 1000 nits is the requirement however the actual specification is much lower.

Peak Brightness: 400 cd/m², or preferably higher.

Black levels (pixel pitch): 0.40 mm, or lower.

Color depth: 10-bit (8+2-bit)

Color space: 90% DCI-P3 coverage, or greater.

Backlight local dimming.

It's a 10 bit panel which confirms to the 400 nit rating however I can imagine with the local diming as is that it's above that. I don't think it's 90 percent dci-p3 either.

Re: Actual nits

Unarmedberetta — Sun, 13 Feb 2022 21:10:11 GMT

The requirement for "true HDR" people say is 1000 nits. I believe that this is because most content is filmed at 1000 nits. Though there isn't many TVs that actually are above this. Say some high spec models (oled sit between 400 - 800.

The actual specification is

Peak Brightness: 400 cd/m², or preferably higher.Black levels (pixel pitch): 0.40 mm, or lower.Color depth: 10-bit (8+2-bit)Color space: 90% DCI-P3 coverage, or greater.Backlight local dimming.

Re: Actual nits

tarbat — Mon, 14 Feb 2022 09:10:07 GMT

@Unarmedberetta wrote:
Don't suppose anyone managed to measure there peak brightness plus a local dimming test when the TV first came out?

I tested my neighbour's Glass TV when they first received it. Peak Luminance with HLG test patterns 10% window (by R.Masciola) was 587 cd/m². They rejected the TV and sent it back, partly due to flickering FALD zones.

I have also speculated about whether Sky would be able to fix the flickering FALD zones and enable local dimming!

@tarbat wrote:
The question is, can Sky fix the flickering FALD zones and enable local dimming?

It wouldn't suprise me that with local dimming disabled, peak luminance would be lower.

EDIT: I posted about this back in early November - see https://helpforum.sky.com/t5/Sky-Glass/Awful-sky-glass-uhd-picture/m-p/3828965#M18680

Re: Actual nits

Godfrey — Mon, 14 Feb 2022 10:53:45 GMT

@Unarmedberetta wrote:
The requirement for "true HDR" people say is 1000 nits.

Godfrey.

Re: Actual nits

Unarmedberetta — Mon, 14 Feb 2022 11:11:05 GMT

I don't get what your trying to say?

I was refering to HDR10. Apart from sky I don't use HLG. Infact most of my content is streamed from a Xbox in Dolby vision for the most part.

Re: Actual nits

tarbat — Mon, 14 Feb 2022 11:29:30 GMT

@Unarmedberetta wrote:
The requirement for "true HDR" people say is 1000 nits. I believe that this is because most content is filmed at 1000 nits. Though there isn't many TVs that actually are above this. Say some high spec models (oled sit between 400 - 800.

Depends what you mean by "requirement". Any TV with a peak luminance above 203 cd/m² should be able to deliver an "adequate" picture in HDR (PQ) and Dolby Vision.

Obviously to get the true impact of the high dynamic range, you need a high contrast ratio. The TV should meet the UHD Premium specification, so either:

1,000 cd/m² peak luminance and less than 0.05 cd/m² black level (LCD TVs)
540 cd/m² peak luminance and less than 0.0005 cd/m² black level (OLED TVs).

Content isn't "filmed" at 1,000 cd/m², it will be graded to either 1,000 cd/m² (common), or 4,000 cd/m² (also common), or even 10,000 cd/m² (less common).

Re: Actual nits

tarbat — Mon, 14 Feb 2022 11:33:02 GMT

@Unarmedberetta wrote:
I don't get what your trying to say?

I was refering to HDR10. Apart from sky I don't use HLG. Infact most of my content is streamed from a Xbox in Dolby vision for the most part.

Sorry, I only looked at the calibration for HLG. The Glass TV, even with only 587 cd/m² peak luminance should be able to deliver an adequate HDR (PQ) picture. But without local dimming, the contrast ratio is unlikely to deliver a truely impressive HDR experience.

Re: Actual nits

Unarmedberetta — Mon, 14 Feb 2022 11:50:30 GMT

You are correct. The TV will provide a good experience. Certainly better than all the entry level and will compare to most of the mid range.

Once calibrated and the settings tweeked you will find the TV gives a good imagine overall however the higher the peak the better in HDR highlights. Like light sources etc.

Hence me questioning as my TV was only giving 485.

I do believe them messing with local diming has caused this.

Re: Actual nits

Jayboy1990 — Mon, 14 Feb 2022 11:54:09 GMT

My question is how can it be proven once and for all that local dimming isnt active/working? - Id there a way to work this out as a consumer?

I have zero experience/knowlege here but if you can prove once and for all surely this will result in forcing Skys hand to respond?

Re: Actual nits

Unarmedberetta — Mon, 14 Feb 2022 11:57:01 GMT

Very informative thank you.

Sorry wires crossed. I should have said graded and not filmed. As you have stated the more common to be 1000 or 4000. From my understanding no disable can even reach 10000.

I'm fully believe that it's the fact the local diming that's the issue. Since you mention the tv had flicking can you confirm that the LEDs did they shut off when displaying black?

Re: Actual nits

tarbat — Mon, 14 Feb 2022 11:59:10 GMT

@Jayboy1990 wrote:
My question is how can it be proven once and for all that local dimming isnt active/working? - Id there a way to work this out as a consumer?

I have zero experience/knowlege here but if you can prove once and for all surely this will result in forcing Skys hand to respond?

Yes, there are several test videos available on Youtube. My preference is this one:

[video]

I don't have Glass otherwise I'd do the test myself.

Re: Actual nits

Unarmedberetta — Mon, 14 Feb 2022 12:11:26 GMT

Yeah I use the same one.

Now with local dimming enabled the entire screen is lit up and the LEDs do not switch off.

Giving more a inky black affect.

With this affect you cant spot any blooming however it's clear that blacks could be better.

Below is from my TV. Camera doesn't fully capture it but as you can see the hints of blue are the backlight

That is from a u7qf. Which uses local dimming the back light is fully shut off. The camera does worsen the image as blooming was not that bad and the panel was shut off.

Re: Actual nits

M3rk — Mon, 14 Feb 2022 14:19:00 GMT

@Unarmedberetta wrote:
Yeah I use the same one.

Now with local dimming enabled the entire screen is lit up and the LEDs do not switch off.

Giving more a inky black affect.

With this affect you cant spot any blooming however it's clear that blacks could be better.

Below is from my TV. Camera doesn't fully capture it but as you can see the hints of blue are the backlight

That is from a u7qf. Which uses local dimming the back light is fully shut off. The camera does worsen the image as blooming was not that bad and the panel was shut off.

lol i might have the wrong end of the stick, are we saying that the above shows, glass looks better??

Re: Actual nits

Unarmedberetta — Mon, 14 Feb 2022 14:26:19 GMT

No infact sky looks worse due to he blacks now showing black.

The image for the hisense was taken at night hence it looks worse. In person it's better.

I'm refering to black levels. On the FALD displays to which I have experience with the LEDs would turn off. Certainly lowering the black levels to pretty much black while brighting up the parts of the screen which required it.

Imagine a cave exit. All around you is pitch black apart from the exit. A FALD tv would turn of the LEDs in the black to give a full reputation where a none FALD such a direct lit could never turn of the LEDs and would attempt to give a closer to black as it could.

Now do I think FALD has been disabled. Not fully no. I feel it's still there however due to the flickering issues that they have raised the black levels while they try and fix the issue with a patch.

Attached is a photo from a a game I was playing. As you can see the near right is black however the LEDs were still on. The camera is also picking up the blooming around the HUD. In a dark room is easy to tell that the LEDs are not switching off.

Re: Actual nits

TimmyBGood — Mon, 14 Feb 2022 14:33:58 GMT

Have to say that as a parent who's become far too familiar with the application of tea-tree conditioner and a fine-tooth comb over the years, the title of this thread is making my scalp itch ; (