Spears & Munsil 4K UHD HDR Benchmark (Test Discs) May 15, 2023

[DisplayCalNoob]

Originally Posted by Stacey Spears

I believe it is chroma ringing and it stands out more in HDR because it is HDR. Here are some full images that I convert to RGB (8-bit) using bicubic and bilinear upsampling. This is an HDR image, but you will most likely be viewing it in gamma, so it is not as obvious. If you zoom in very far using nearest neighbor, to avoid any interpolation or smoothing, you will see it.

You will see the same chroma ringing in bicubic but not in bilinear.

Bicubic


Bilinear


Bilinear - 709 instead of 2020 upsampling / color conversion


It is probably best to save it to your local machine and zoom in.

This is the new version where I mentioned the added color bars in the color space conversion section.

Now I have to recheck for chroma ringing when I get home, now that I fully understand what I'm looking for and at. Then go through the different modes that don't have it.

[5150z]

Originally Posted by wxman2003

I would like to hear what you think of image quality with DV when you switch that port to PC. I don't notice any difference when I labeled the port PC. I noticed when set to PC, Black level in the picture setting switches from Auto to Low and is greyed out.

Will do! Likely tonight. Frankly, I'm not expecting much, if any, change either. I'll update soon.

**Update** I see no difference when changing to PC mode with DoVi content, as stated by Chros in a post above. And, as with wxman2003, I have a 6 Series LG too (B6 to be specific), and TV-led is the only option. Thank you to all of you for the help.

[Deciazulado]

Originally Posted by chros

(My other reply is still pending - not visible - for whatever reason)

made it visible. (Balling & you being newly minted members triggers that)

[Balling]

BTW, I forgot to mention but DCI-P3 info is available in CTA‐861‐G (version from November 28, 2017), that coasts 0.00$ on official site. There you can read about all DCI-P3 stuff and how to use Additional Colorimetry Extension. On page 60 you can understand that DCI-P3 R’G’B’ (theater) and DCI-P3 R’G’B’ (D65) are only RGB as on page 61, where YCC formats are described, DCI-P3 is not mentioned. There is also a very nice Note on page 105 that "Note that sink shall understand two types of DCI-P3 colorimetry in [51] and [52] when this flag is set to one", i.e. if Colorimetry block DCI-P3 flag is set to 1, sink must understand both types of DCI-P3 that is done in Gamut metadata packets.

ICtCp digital format will only be in CTA‐861‐H (also free), which was just finalized. I rechecked it: ICtCp is actually YCC format. Pixel Data with ICTCP colorimetry shall use the following component mapping: The I component shall be carried in the Y Color Component Sample, CT shall be carried in the CB Color Component Sample, and CP shall be carried in the CR Color Component Sample.
@chros Links are not allowed yet, I suppose.

[SeeMoreDigital]

Originally Posted by wxman2003

I would like to hear what you think of image quality with DV when you switch that port to PC....

When playing Dolby Vision content via my OPPO, if I select the 'PC' icon on my 2016 LG television (which is fitted with an 8-bit panel), I see feint horizontal banding...

[chros]

Originally Posted by Deciazulado

made it visible. (Balling & you being newly minted members triggers that)

Cheers, no worries (I just didn't know what happened, because the post request took really long time as well, and the message disappered quickly in the end.)

Originally Posted by Balling

@chros Links are not allowed yet, I suppose.

Ah, it makes sense, thanks.

Then I'll do a separate post now with links again

[chros]

@Stacey Spears, so here is my previous post, you should also be able to reproduce it (according to other CX owners).

And since we are at it, LG's HDR10 processing has another big issue with 2018 sets (B8 and C8 as well). this one happens in non-PC mode as well: cyan/magenta issue with low APL HDR10 scenes (SDR and DoVi modes are fine).
I'm not sure how previous models behave and not sure about C9, but CX owners said that they can't replicate the issue on their sets, so I thought it's finally fixed until Vincent's recent

DV streaming vs HDR10 Bluray review

: he mentions blue issue with the Lion King scene

We assume that LG's BT.2020 gamut mapping is the culprit, because there's no issue when madvr tonemaps to SDR and the display uses it's native DCI-P3 gamut. Unfortunately we don't know any way to disable bt.2020 processing with HDR10 on 2018 sets (I know that CX has the secret gamut mapping setting), so we couldn't verify this theory.

To try to replicate this issue easily:
- here is a 1 minute sample of The Witcher S01E04 in HDR10 from around 53:20
- playback the sample in HDR10, take a look at the cyan-ish light through the window at the back of the small chamber where 2 of them are talking
- pause the playback, then look at the same scene on Netflix using DV: this is how it should look like (switch between the two source to notice the difference, if it's not that visible at first)
- if you also see difference then: switch the gamut mode of your CX to DCI-P3 with the HDR10 sample to see whether it solves this issue

[Balling]

Oopsie, ICtCp is actually YCC format. Rechecked CTA-861-H ;(

[Stacey Spears]

Originally Posted by SeeMoreDigital

When playing Dolby Vision content via my OPPO, if I select the 'PC' icon on my 2016 LG television (which is fitted with an 8-bit panel), I see feint horizontal banding...

If you see additional banding, then I would not use PC mode. We could not detect any on Don's panel with HDR10.

I know the 7 and above all use 10-bit panels, don't recall on the 6.

[Stacey Spears]

Originally Posted by 5150z

Will do! Likely tonight. Frankly, I'm not expecting much, if any, change either. I'll update soon.

**Update** I see no difference when changing to PC mode with DoVi content, as stated by Chros in a post above. And, as with wxman2003, I have a 6 Series LG too (B6 to be specific), and TV-led is the only option. Thank you to all of you for the help.

On the 6 series I know the B and C series use different parts for video processing, unlike later models. All of my testing is on the C6.

[SeeMoreDigital]

Originally Posted by Stacey Spears

If you see additional banding, then I would not use PC mode.

Agreed... I don't

I first noticed the effect after plugging the OPPO and the PC's HDMI inputs the wrong way around on the back of the TV.

If you play Forrest Gump and navigate to 00:10:22, where Sally Field is looking for young Forrest you should see it...

[Stacey Spears]

Originally Posted by DisplayCalNoob

Now I have to recheck for chroma ringing when I get home, now that I fully understand what I'm looking for and at. Then go through the different modes that don't have it.

Ringing stands out a lot more on test patterns due to their hard edge transitions than they do in real-world material. If you see them on non-test patterns, it may be 2D animation.

MadVR Envy has some great up sampling algorithms that don't ring and maintain detail. The AI upsampling works really well. I am getting Envy for myself to use.

[Penton-Man]

Originally Posted by Balling

available in CTA‐861‐G ....Links are not allowed yet, I suppose.

https://forum.blu-ray.com/showthread...a#post12923238

eh, I notice the link from the post in 2016 ^ is no longer viable, so here - https://shop.cta.tech/products/a-dtv...760.1615481965
and for H - https://shop.cta.tech/products/a-dtv...760.1615481965

[wxman2003]

Originally Posted by Stacey Spears

If you see additional banding, then I would not use PC mode. We could not detect any on Don's panel with HDR10.

I know the 7 and above all use 10-bit panels, don't recall on the 6.

6 series have 10 bit panels, but only capable of tv-led DV. Whereas 7 and above can do both player led and tv led.

[Stacey Spears]

Would everyone mind providing their top 5 list of patterns they would like to see a video explaining? I am sure in the end, it is all of them, but for now, trying to figure out which videos we should make first.

The plan is to launch the videos this fall. We will have one video per week, at least that is our goal. We will have both interviews and instructional videos. Maybe one interview per month with three instructional videos. e.g. the first video will be an interview with Don and myself. it will be the Spears & Munsil origin story. And one of the first instructional videos will be Luminance Loading.

The interview videos will not be live. I am hoping that those videos will be published as UHD HDR. As with anything, there are the aspirational goals and then reality.

So please, top five test patterns you would like to see videos for.

[Stacey Spears]

Here are the latest menu mock-ups:
Disc 1
Disc 2
Disc 3

Here is a doc that provides a high level overview of each section. It also has some basic notes on our patterns accuracy and levels. We will be merging this with the beginners guide to make the printed manual for the disc.

At least one montage will be cut from disc 3 as its over the 87 GB of HTR. HTR allows you to go over 100 Mbps for combined audio and video. You can only use HTR on a portion of the disc. With a 100GB disc, that limit is ~87 GB.

Feel free to ask questions about any of the patterns mentioned in the mock-ups.

Disc 1 is currently in authoring while Disc 2 is currently encoding. Disc 3 is mostly encoded, but not QCd yet. There are 3 montages left to encode. This week the motion and motion HFR patterns on disc 2 are encoding. This is the slowest section to encode. The only thing left, after the motion section, is Analysis, which are all of the static window patterns.

[nathan_h]

These selections could go at least two different directions.

1. Focus on the core patterns that a newbie should be introduced to.
2. Focus on some of the more esoteric but unique and powerful patterns that a more experienced hobbyist should learn about.

However, since the goal is to cover everything AND they don't necessarily have to be tied to individual patterns, it occured to me when looking through the menus for ideas about which patterns to focus on: Why not a video discussion ALL the patterns on a given menu, such as:

http://spearsandmunsil.com/wp-conten...5740357110.png

What you would say about individual patterns here is often going to be redundant among the different patterns accessible from this particular menu....so instead of repetitive videos, why not one video that explains the overall use/intent, and then mentions why the different patterns are useful?

(EDIT: I was looking at the wrong list but the concept applies.)

[rickardl]

What is "Optical Comparator"? Patterns for visual (by eye) comparisons?

[Stacey Spears]

Originally Posted by rickardl

What is "Optical Comparator"? Patterns for visual (by eye) comparisons?

An optical comparator is old school grayscale calibration hardware. Here is an example of one that the ISF used to sale 20 years ago.

Back in the day, these were much cheaper than a colorimeter. Really old school would be a Kodak gray card with a D65 light source to use as reference. In fact, our new color temp pattern is also designed to use an optical comparator.

You might pull your hair out trying to use one, but for those that can't afford a colorimeter, it is an option.

There used to be a popular one that Joe Kane recommended back in the day. It was ~$1000 (TVS Pro), which was much cheaper than a colorimeter back then. Now you can get a colorimeter for under $300. There is a thread from 2002 on AVS on how to make one for $60 in parts. Guy Kuo has a post on the subject as well.

[Stacey Spears]

Originally Posted by nathan_h

What you would say about individual patterns here is often going to be redundant among the different patterns accessible from this particular menu....so instead of repetitive videos, why not one video that explains the overall use/intent, and then mentions why the different patterns are useful?

Thank you for the feedback.