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Black levels and comparison with Calman

I have investigated on my E8 (FW .55), using i1D3 for generaiung, checking and comparing 1DLUT and 3DLUT.
Here some of the comparison I have done based on 120 Nits Target:
First of all I was quite curious to compare a 13 cube (on the top - 2 hours) with a 17 one (4 hours):

I have found the results very good. Clearly a 17 cube is better, but if you don't have time also a 13 one is good.
I have compared them using Ted's pattern, and I could spot differences.
Also a comparison of the 17 Cube with a manual calibration (on the top)

shows the related improvements. Problem this manual is that red at 100% is out range (moved right - verified with Jeti) - not sure if depending from .55 sw. Anyhow fixed with a 3DLUT and quite evident comparing side to side. Harder to detect on real contents.
Then I have started comparing with an Autocal case. As time is a constraints for 3DLUT, I have generated a 5000 point 3DLUT. Here the CM result (top) compared to LS 17 cube:

Not so bad, but, when I started comparing, I have found colour banding on blu, specifically on Blue Tunnel.
But I have seen some advantages on black levels. See LS results compared to CM ones on a gray ramp and on a 16-27 squares:

Looking to Ted's Black Tunnel pattern, with Calman I can see 1%. I have also given check to the outcomes with a .20 FW, but still LS is too dark.
But blue banding? Any relation with CM 1DLUT? So I have done my last test: over a CM 1DLUT I have run LS 17 cube (on the bottom) - on the top the 17 cube all CM cube:

And, most important thing, the banding is gone. Also grey scale has improved and grey scale either.

My impressions/conclusions: I think that 1DLUT have the capability to improve black levels. I guess i1DIS is not the best instruments for measuring them and I understand @BlackJoker has gotten better results, but with a Klein.

Worthless to add that 3DLUT generation on LS is great:), but that's something of known
 

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How setting Black Level

I think there is something of unclear when setting the black level in the autocal case.
When I do manual calibration on my OLED, I eventually switch the lights, and then I set gamma, and then the best black level.
Then, I go into the dark :eek: and start my calibration.
But is the best black level ok after automatic autocalibration?
In my case not: in any case black are crunched, and I have, also in a black room, to raise brightes by 2/3 points. This implies a lower average gamma (around 0.7) and some boost at low IRE.


I have also noted that Calman, after autocal, go back in its workflow to brightess and contranst setting.

Any thought/view if a better approach might be follewed?
 

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The link is still active, the forum just cant handle white spaces, so copy the entire thing into your browsers address bar.
Sorry to dig out this old post but the download no longer seems to be available.
Does someone still have the file and could be so nice to send it to me?

Are are any news on the topic? The file was a beta version back then, is there a final version available?
And has anyone tested the i1D3 EDR with CalMAN Home for LG?
 

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The link points to file for building a LS beta. Now that EDR is in the official LS release, so, I understand, there is any reason for copying it. Anyhow you can try with its owner, Steve, through https://www.lightillusion.com/contact.html.

As far as I remember, also Calman has something of similar you can use for I1D3. The same is true for HCFR. They are EDR based, but not taken by XRITE as standard calibration, but added by sw developper.


PS: to try/verify it you need a spectrum. My tests show better accuracy.
 

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The link points to file for building a LS beta. Now that EDR is in the official LS release, so, I understand, there is any reason for copying it. Anyhow you can try with its owner, Steve, through https://www.lightillusion.com/contact.html.

As far as I remember, also Calman has something of similar you can use for I1D3. The same is true for HCFR. They are EDR based, but not taken by XRITE as standard calibration, but added by sw developper.

PS: to try/verify it you need a spectrum. My tests show better accuracy.
Thanks a lot for the info!
I was able to locate the WRGB OLED EDR file in the LightSpace installation (FSI_XM55U_23Jan19.edr)

But it seems CalMAN Home for LG doesn't support using other EDR files than the ones that come with the package.

Since you were able to verify the results with the WRGB OLED EDR file I would be really interested in how much the results are off without it. Do you have any numbers? (Yes, I'm aware the results may vary from device to device)
 

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Thanks a lot for the info!
I was able to locate the WRGB OLED EDR file in the LightSpace installation (FSI_XM55U_23Jan19.edr)

But it seems CalMAN Home for LG doesn't support using other EDR files than the ones that come with the package.

Since you were able to verify the results with the WRGB OLED EDR file I would be really interested in how much the results are off without it. Do you have any numbers? (Yes, I'm aware the results may vary from device to device)
Have a look here: https://www.lightillusion.com/forums/index.php?action=vthread&forum=8&topic=527#msg3280.
AFAIRemember also Calman has its own EDR, but I ahve not measured that. But, as for the one that exists also in HCFR, I expect some accuracy improvements.
 
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With the new 'Hint' based probe matching we are looking into for LightSpace/ColourSpace (posted elsewhere on this forum) the ability to better match a Tristimulus to a Spectro on any non-additive/non-linear displays (WRGB is a perfect example), should be greatly enhanced...

Steve
 

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Discussion Starter #268 (Edited)
I have also noted that Calman, after autocal, go back in its workflow to brightess and contranst setting.

Any thought/view if a better approach might be follewed?
Hi, changing Contrast/Brightness or OLED Light after profiling, with internal 1D/3D LUT loaded internally to the TV, it will undo the correction LUT its been generated and it will shift some thousand colors increasing their dE errors.


For the internal 1D LUT to work as expected; because the Contrast/Brightness controls are located before the 1D/3D LUT tables; set Contrast @ 85, Brightness @ 50 and Color @ 50 value settings.

The normal TV menu picture mode settings: Contrast, Brightness, Color and Tint should stay at default values (these are the bypass processing values) because they are positioned before the 3D/1D LUT tables.

OLED Light can be adjusted to reach the target luminance level during pre-calibration procedure but not adjust it after the profiling or when any 1D/3D correction LUT has been uploaded internally to the TV.


See there for more info: https://www.avsforum.com/forum/139-...-using-lightspace-thread-10.html#post58376960
 

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Discussion Starter #269
I guess I am doing somthing wrong: I generate by convert my 3DLUT, then I do sub-black (as done when generating my 1DLUT), I substract the 1DLUT (as previously generated and exported), I export what I have generated as 3DLUT, I upload it. My warm white becomes very cold.

PS: 3DLUT without substraction works fine. I have not generate a 1DLUT with augmented data, as it was late, and I left the system doing the characterisation during the night.
Now with the new 'Hybrid' method, it works better than the 'Peak Chroma', so the Subtraction of 1D from 3D LUT data is not required, see:

https://www.avsforum.com/forum/139-...ema-calibration-software-77.html#post58349770

https://www.avsforum.com/forum/139-...ema-calibration-software-78.html#post58371542
 

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Discussion Starter #270
Are are any news on the topic? The file was a beta version back then, is there a final version available?
And has anyone tested the i1D3 EDR with CalMAN Home for LG?
Hi,

There one version of WRGB OLED EDR table created from X-Rite for WRGB OLED's, just initially LightIllusion; to provide it quicker to its users; instead of releasing a new installer and different build, they provided details about how to add it manually to existing installation of any LightSpace folder. After some days, its been added properly with new software version release.

I was able to locate the WRGB OLED EDR file in the LightSpace installation (FSI_XM55U_23Jan19.edr)

But it seems CalMAN Home for LG doesn't support using other EDR files than the ones that come with the package.
There other EDR files to the LightSpace folder you found the ''FSI_XM55U_23Jan19.edr'', they are created from X-Rite but they are not available to CalMAN also. (Ask CalMAN why they are not available)

I have highlight these 3 EDR files to the picture below:



So for LightSpace users, to have a better idea when they will these EDR files for the following display types:

The PFS_Phosphor_Family_31Jan17.edr is for WLED display's backlight using are potassium fluorosilicate (PFS) phosphors; displays with narrow narrow band emitting white LED's with 'DCI-P3' gamut coverage.

The NEC_64_690E_PA242W_2013-02-28.edr is for NEC PAxx2 series AH-IPS GBr LED displays, its been used spectral sample from NEC PA242W.

The FSI_XM55U_23Jan19.edr is for LG OLEDs 2018 panel based models, since FSI use the same glass as C8. The spectral data used for this EDR has been generated from the FSI XM55U display (~15K$ post production monitor).

These 3 EDR spectral correction files for i1Display PRO users has been created from X-Rite directly and its available from LightSpace (which using X-Rite SDK) and from HCFR/DisplayCAL (which using custom code programing to operate the i1Display PRO's and not X-Rite SDK)

AFAIRemember also Calman has its own EDR, but I ahve not measured that. But, as for the one that exists also in HCFR, I expect some accuracy improvements.
The EDR files for i1Display PRO's (OEM or Retail users) has been created from X-Rite. The selection you see at CalMAN for OLED is for RGB OLED, with i1Display PRO, its not useful when you want to measure an WRGB OLED.

For that reason its been suggested to CalMAN users with WRGB OLED's to not use the OLED but the RAW XYZ (its called like that the default calibration mode in CalMAN, its call as 'Generic CMF' table in LightSpace, or as 'None' Spectral Sample in HCFR)

Generic CMF/RAW XYZ, is the factory sensor calibration mode (without any added EDR spectral correction), the meter will send XYZ data values to calibration software and the software will convert them using the default CMF standard (CIE1921) to xyY readings.

When you have active an EDR spectral correction table, the Generic CMF/RAW XYZ is combined with spectral data of the EDR to provide the corrected XYZ and then its sending the data values to the software.

For the RGB OLED table of i1Display PRO (which available to CalMAN/LightSpace/HCFR/DisplayCAL), X-Rite used a Sony PVM-2541 RGB OLED Monitor to create that OLED spectral correction EDR file which can be useful when you will measure the Sony or FSI (Flanders Scientific Inc.) RGB OLED Broadcasting Monitors and not a consumer LG WRGB OLED or the following brands which are using LG's WRGB OLED panel also: Sony, Panasonic, Toshiba, Loewe, Philips, Skyworth, Metz, Grundig, Vestel, Arçelik and Bang & Olufsen.
 

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Discussion Starter #271
I think there is something of unclear when setting the black level in the autocal case.
When I do manual calibration on my OLED, I eventually switch the lights, and then I set gamma, and then the best black level.
Then, I go into the dark :eek: and start my calibration.
But is the best black level ok after automatic autocalibration?
In my case not: in any case black are crunched, and I have, also in a black room, to raise brightes by 2/3 points. This implies a lower average gamma (around 0.7) and some boost at low IRE.
As you know well, there a lot of different firmware released from LG and periodically a new firmware release can affect how the panel is responding (not all the times).

So there FW released which clip near black natively, so the 1D LUT will try to resolve that during the initial 1D LUT profiling procedure.

But there times where issues can't be completely resolved using 1D LUT + 3D LUT, probably about some internal processing. So there scenarios where correcting Near Black via Brightness slider, doing RGB-High calibration (so skipping the 1D LUT profiling) and perform directly 3D LUT (which is including 33-Point Grayscale inside) will provide better final results.

From testing, even TV's with same firmware, using exact same meters and settings, but from panels coming from different market regions, to one user the 1D LUT + 3D LUT works better, to the other user skipping 3D LUT works better.

Looks like there some differences over different electronics? (there 2 kind of main board for example if you search parts for LG, tuners have difference but who knows if there other...)

Probably periodically LG is changing some stuff to different manufacturing lines or different assembling factories.... I have no idea.
 

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Discussion Starter #272
LG 2019 Template (C9/E9/G9/W9)for DeviceControl Interface is now available for Free to LightSpace users. Its ready a lot of time ago, and a lot of users currently using it.



The page where you submit to request access has not been updated to talk for LG 2019 release yet, but its planned to be updated when complete Guide for LG OLED Profiling for LightSpace will be released. (working on it)

The procedure is exact same as for LG 2018 Template.

Current DeviceControl Interface users, if they will refresh their Cloud, they will see the LG 2019 Template available, but see how to receive the update there: How to receive the latest LG Template Update for DeviceControl Interface.

You can see very detailed instructions about how to request free access, how to setup setup and connect your LG OLED TV using LG 2018/2019 Templates for DeviceControl Interface here.

Its not easy to copy past all the info pictures/text here.

If there interest about B9, it may added instantly, but generally people prefer to invest no other LG 2018/2019 models and not to B8/B9 models.

LG C8/E8/G8/W8/C9/E9/G9/W9 OLED TV's have (33-Point Cube 3D LUT) while the LG B8/B9 has the standard version (17-Point Cube 3D LUT) of this technology.



The number of color points that can be stored is about 7.3 times greater on the LG C8/E8/G8/W8/C9/E9/G9/W9 (35937) vs B8/B9 (4913).

The LG C8/E8/G8/W8/C9/E9/G9/W9 OLED TV's advantage of having more color data points in the 3D LUT is that there are then fewer interpolated points between adjacent calibrated points compared to LG B8/B9.

This allows more accurate interpolation, fewer quantization errors, and better output value continuity at the calibrated data points, which yields fewer image artifacts and smoother color gradients in the rendered image.

Additionally, LG C8/E8/G8/W8/C9/E9/G9/W9 OLED TV's users will be able use larger patchsets from the 'standard' 17-Point Cube (4913 color points), like 21-Point Cube (9261 color points) which can provide better final results.
 

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Discussion Starter #273
LG 2018/2019 OLED's feature 10-bit (1024 entries) 1D LUT tables with 15-bit precision values and 33-Point Cube 3D LUT tables (35937 individual colors) for C8/E8/G8/W8/C9/E9/G9 or 17-Point Cube 3D LUT tables (4913 individual colors) for B8/B9 with 12bit precision values.

Internal LUT's are 0-1023 with the video black '64' mapped to '0' of the LUT's.

LG TV Black setting will remap black to '64' with Low (limited range) or to '0' with High (full range).

LightSpace's color engine will calculate the colorspace conversion LUT correction data with 16-bit precision and then export to DeviceControl Interface 1D/3D LUT file format.

LightSpace will not connect directly with the LG OLED TV's for DDC or LUT management, a FREE external user utility; DeviceControl Interface using LG 2018/2019 Template; will be used for that job.



Using LG OLED 2018/2019 Template for DeviceControl Interface you can perform basic DDC (Direct Display Control) required for initial pre-calibration adjustments but also direct upload/management of 1D/3D SDR LUT correction tables generated from LightSpace to the 5 available Picture Modes: Cinema, Technicolor Expert, ISF Expert Bright, ISF Expert Dark and Game (with low latency).

LG OLED 2018/2019 Template combined with LightSpace features a complete 1D/3D LUT backup solution.

Another advantage of 1D LUT upload capability using LG OLED 2018/2019 Template combined with LightSpace is that from one measurement run of 33-Point Grayscale (Quick Profile -> Gray Only Large), you can generate 1D LUT tables with different gamma exponent value (2.4 / 2.35 / 2.2 etc.) or using custom White Point coordinates to upload for different picture modes without taking new measurements, since you will have collected Grayscale measurement profiling data from native gamma based panel response (10000K color temperature) of the TV.
 

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Discussion Starter #274 (Edited)
LG OLED Profiling - Calibration Notes

The following calibration notes, setting or procedure recommendations can be followed by any LG 2018/2019 OLED TV user when it will be performed a display profiling using internal SDR LUT capabilities with LightSpace or CalMAN software, when DisplayCAL/ArgyllCMS with madVR Renderer will be used as 3D LUT software loader, when any external hardware 3D LUT Box (eeColor LUT Box or Lumagen Processors) will be used as LUT holder device, or when only a manual SDR calibration will be performed using the available TV calibration controls by the users.

Disable Image Enhancement features

The purpose of a TV is to display the video input signal as it is, and it shall not attempt to 'enhance' or otherwise alter the image.

These TV functions below should be turned off before taking any measurement because they will affect calibration. Some can be enabled only after calibration.

1) Energy Saving:

Adjusts screen brightness automatically to reduce energy consumption. Turn it 'OFF'.

2) OLED Panel Settings -> Screen Shift:

Shifts the entire image on screen by a small number of pixels periodically. You can enable it only after calibration.

3) OLED Panel Settings -> Logo Luminance Adjustment:

Technology to recognize static logos, reduces the luminance of logos and surrounding areas. Turn it 'OFF'.

4) Expert Settings > Dynamic Contrast:


Corrects the difference between the bright and dark areas of the screen for optimal results depending on the brightness of the picture. Turn it 'OFF'.

5) Expert Settings > Super Resolution:

Adjusts the resolution to make dim and blurred images clearer. Turn it 'OFF'. You can enable it after calibration.

6) Additional Settings - Eye Comfort Mode:

The color temperature will be adjusted to reduce eye fatigue. Turn it 'OFF'.

7) Picture Options > Noise Reduction:

Removes small dots that stand out so as to make the image clean. Turn it 'OFF'. You can enable it after calibration.

8) Picture Options > MPEG Noise Reduction


Reduces the noise produced during the creation of digital video signals. Turn it 'OFF'. You can enable it only after calibration.

For LG 2018 C8/E8/G8/W8 OLED TV's it will perform a quad-step MPEG Noise Reduction (with a 2-pass smooth gradation) while with LG 2018 B8 OLED TV it will perform a dual-step MPEG Noise Reduction (with a single pass smooth gradation).

This leads to a more effective banding removal on part of the LG C8/E8/G8/W8 vs B8 but given that the decontouring filters are used together with the noise reduction ones, the LG C8/E8/G8/W8 are more likely to exhibit loss of fine detail (particularly with high quality content) than the LG B8.

The MPEG Noise reduction setting, however, is granular so it's possible to find the right balance between minimizing banding artifacts that are present in the content, and keeping fine-detail largely intact.

Since the native bit-depth of the WRGB OLED panel used in LG 2018 OLED TV's is 10-bit, you'll only need to use the MPEG Noise Reduction (which controls Smooth Gradation filters) only in case the posterization is in the content (due to inadequate bitrate, for example) because otherwise all LG 2018 OLED TV's are natively capable of delivering smooth gradation (due to their 10-bit panels).

9) Picture Options >Real Cinema:

LG OLED's are using 120 Hz panels, they will do 5:5 pulldown to the 24p input signals from external sources or internal apps with Real Cinema On; for judder-free native 24p playback.

For 24fps content it will display each frame 5 times. 24 * 5 = 120, the exact refresh rate of the panel in Hz.

With Real Cinema 'OFF', the TV converts 24p input as 60p internally, this will add a 3:2 pulldown judder, even on 24p sources. Turn it 'ON'.

10) Picture Options > Motion Eye Care:

Automatically adjusts brightness and reduces image blur based on image data which reduces eyestrain. Turn it 'OFF'.

11) Picture Options >TruMotion:


Frame interpolation and insertion to increase motion sharpness, smoothness, and reduce judder. Turn it 'OFF'.

When it's 'OFF', it will keep the 'original' signal processing without motion compensation.
 

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Discussion Starter #275
Calibration Notes for LG 2018/2019 Profiling

Grade-1 SDR Reference Monitor/TV Calibration Targets

The viewing of accurate images depends on an accurate calibration of the display, control over the viewing environment (lightning and room decor), as well as the appropriate placement of the observer relative to the screen.

The Reference Viewing Environment can be considered one where color critical decisions are made, while the Home Viewing Environment is where finalized deliverables are viewed, with the intent to best match the original artistic intent, as defined by the director and colorist within the Reference Viewing Environment.



The goad of home TV calibration is the Home Viewing Environment to match the Reference Viewing Environment image.

Within the professional industries reference monitors (Grade-1) are the standard for color critical work.



EBU TECH 3320 (Version 4.1 - September 2019) - User Requirements for Video Monitors in Television Production, defines the technical characteristics for video broadcast monitors used in a professional TV production environment for evaluation and control of the images being produced.

Its describing the definition of Grade-1 SDR Reference Monitor with Standard Dynamic Range capabilities.

Grade-1 Monitors are devices for high-grade technical quality evaluation of images at key points in a color grading production workflow.

They are used for critical evaluation during post-production.

As a minimum requirement, these monitors shall have the quality properties of the image system they are used to evaluate.

It is expected that all applied technologies are state-of-the-art at this level as the Grade 1 monitor is a 'measuring instrument' for visual evaluation of image quality.

Grade-1 SDR Reference Monitor should be been calibrated and capable to produce a reference luminance level of 100 cd/m2 (nits) for 100% White (235 level @ 8-bit) patch on the screen.

Automatic Brightness Limiter (ABL) functions shall not be used for Grade-1 SDR Reference Monitors, this means that the monitor need to be capable to display 100 cd/m2 with a full field 100% Reference White pattern also.

100% luminance on the screen corresponds to a 10-bit luma signal of digital level 940, and the black level corresponds to a 10-bit luma signal of digital level 64.

100% luminance on the screen is defined as the luminance of a luma signal of digital level 940, but levels 941 through 1019 should also be correctly displayed.

The highest value of 10-bit luma signal is digital level 1019. The luma level 1019 is called 'Super-White' or '109% White'.

For the luminance gamma characteristic (Electro-Optical Transfer Function) of the screen, its recommended that a nominal value of 2.4 gamma to be used.

 

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Discussion Starter #276
Color Matching Functions & Metamerism

The CIE 1931 color matching functions (CMFs) are the basis of all colorimetric measurement systems.

Earlier studies intended to correct historical imperfections in the original data used as the basis of the CIE 1931 CMFs, but like the CIE 1964 Supplementary Standard Observer, have never found widespread favor, because they result in different numbers across the whole colorspace.

Color scientists attempted to define a more accurate CMF but they resulted in a set of CMFs which can solve the metamerism issue for discrete populations of individuals but this would probably not be practical in an operational environment.

These inaccuracies were not a problem when all display devices were CRTs with color reproduction based on very similar phosphors.

With the introduction of LCD displays with LED backlights, and now OLED displays, it has become apparent that these errors result in displays where the white points match when measured may look different, and when matched visually may measure differently.

For Matching Displays that use Different Illumination Technologies, the Perceptual White Point Matching method can be used.

Using a custom coordinate White Point, it may be a practical compromise such that the display may meet both the requirements of written standards, and enable the visual match that is so important in the television production environment.

LG Electronics with Dolby Laboratories have published an article during SID's Display Week 2018, its available inside to SID Symposium Digest of Technical Papers - Volume 49, Issue 1 (May 2018) issue.

For that study, 'Correcting Metameric Failure of Wide Color Gamut Displays', using 13 reliable observers they performed a visual color matching method trying to match a Reference Grade-1 CRT with the LG OLED and they found that to perceptual match the Reference White of CRT, a custom White Point with x: 0.308 y: 0.313 coordinates has to be used for the LG OLED.

Also LG has worked closely with Technicolor to incorporate Technicolor's in-house D65 perceptual match White Point target, by adding a custom target white point with co-ordinates of x: 0.300 y: 0.327.

But these coordinates are not really working, because Technicolor tried to match a Xenon DCI Cinema Projector as reference (with DCI primaries and D65 White Point), so these coordinates are only helpful for those which are working in post-production and use LG OLED's as client view monitors, for the commercial cinema release of the movie.

For home video release of a movie, a projector as reference is never being used, only with monitors its been performed the mastering of SDR home release of the movies, so there no point for anyone to use a Technicolor custom White Point (for home viewing).

As usual with that recommendation, LG has confused once again the consumer world, it has done it at past many times, with various PDF's with calibration notes for HDR calibration which never worked (even the digital values where incorrect to these PDF, digital bits of PQ % levels).

Each colorspace (REC.709 for home release or DCI-P3 for commercial cinema release) while they use exact the same xy coordinates to create the D65 White Point, each colorspace is using different mixture of primary colors luminance to archive that, while both have 6504K color temperature.

When you use the RGB Balance Chart of a calibration software and see the three (R/G/B) Channels Bars at exact 100% = 0 dE; doesn't mean that it has been used equal percentage of luminance per each color channel.

The calibration software it's doing the normalizing the luminance ratio per primary color internally according to the selected colorspace target options to provide to the user interface a more calibration friendly chart.



REC.709 Colorspace D65 White Point (x: 0.3127 y: 0.329, 6504K) is using Red 21.27%, Green 71.52% and Blue 7.22% luminance per each color channel.

DCI-P3 Colorspace D65 White Point (x: 0.3127 y: 0.329, 6504K) is using Red 22.9%, Green 69.17% and Blue 7.93% luminance per each color channel.

REC.2020 Colorspace D65 White Point (x: 0.3127 y: 0.329, 6504K) is using 26.27%, Green 67.80% and Blue 5.93% luminance per each color channel.
 

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Discussion Starter #277
Calibration Notes for LG OLED

HDMI Ultra HD Deep Color



That setting name can confuse users because it's not clearly describing what is actually doing.

Historically, outputting a 'Deep Color' video signal from HDMI is one of the specifications found in the HDMI 1.3 format.

HDMI 1.3 supports 10-bit, 12-bit and 16-bit (RGB or YCbCr) color depths, up from the 8-bit depths in previous versions of the HDMI specification.

Deep Color support will allow to use additionally the xvYCC expanded colorspace, named also as Extended-gamut YCC or x.v.Color. (IEC 61966-2-4:2006)

Using xvYCC-encoded movie titles like Sony's 'Mastered in 4K' SDR Blu-Ray Discs, it will allow to travel through existing digital YCC data paths of YCC values that, while within the encoding range of YCC, have chroma values outside the range 16-240, or that correspond to negative RGB values, and hence would not have previously been valid.

LG 2018 OLED TV's are equipped with 4 HDMI 2.0b (HDCP 2.2) input ports while LG 2019 TV's are equipped with 4 HDMI 2.1 (HDCP 2.3).

For each HDMI Input, the LG UltraHD Deep Color setting will provide the capability to swap between two different pixel clock rates of video signal transfer, which will affect the supported resolutions/bit-depth per colorspace also.

With LG 2018 UltraHD Deep Color 'ON', the HDMI Input will be clocked @ 600 MHz and capable for up to 18 Gbps data rate.

With LG 2019 UltraHD Deep Color 'ON', the HDMI Input will be clocked @ 1.2 GHz and capable for up to 48 Gbps data rate.

With LG 2018/1029 UltraHD Deep Color 'OFF', the HDMI Input will be clocked @ 300 MHz and capable for up to 10.2 Gbps data rate.

As Deep Color defined the capability to transfer higher from 8-bit per color channel video signal, you can actually send UltraHD with 'Deep Color' with that setting disabled, if you will send SDR or HDR10 2160p24 YCbCr 4:2:2 10-bit as it requires only 8.91 Gbit data rate.

If you have an UHD capable player (or SDR with 2160p upscalling) then set LG's UltraHD Deep Color to 'ON' while if you have an SDR capable player then set it to 'OFF'.
 

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Discussion Starter #278
Calibration Notes for LG OLED


LG OLED Panel Auto Brightness Limiting (ABL)

The Peak Luminance of all LG 2018/2019 OLED TV's models is identical.

But there is an ABL (Auto Brightness Limiter) active at all these LG OLED TV's for the purpose of preventing them to consume too much power when displaying content with preponderance of bright elements, and protecting internal components from overheating.

The impact of the ABL, however, is limited to high-APL content such as hockey and winter sports during which can be observed a brightness reduction as the APL increases.

APL is the average level brightness (Luma) of the total numbers of pixel of an video image frame; defined as a percentage of the range between blanking and reference white level.



The LG 2018/2019 OLED TV's are able to reach about 150 cd/m2 on 100% APL using when you will take measurement using an 100% White full field pattern, so there is still some brightness headroom even for high-APL scenes because SDR content is mastered to a 100 cd/m2.

For reference level SDR movie home playback; for being considered as 'Grade-1'; the TV should be capable to display calibrated colors using the color primaries (REC.709 color gamut) and reference white (D65), as specified in the relevant SDR video standard ITU-R BT.709-6 (Parameter values for the HDTV standards for production and international programme exchange - June 2015).
 

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Discussion Starter #279 (Edited)
LG OLED Panel Automatic Static Brightness Limiter (ASBL)

LG OLED TV's have a function which we call it in calibration world as ASBL (Automatic Static Brightness Limiter).

This function is enabled by default to all OLED's and it will automatically dim the picture when OLED TV will detect that you are displaying static images (like patterns windows during measurements/profiling) after some period of time.

ASBL works by detecting APL changes.

This function needs to be disabled before taking any measurement because it will affect calibration and panel response. If you like; you can enable it after the end of the calibration, or leave it disabled forever.



To disable that ASBL function ('TCP' is called in Service Menu), you will need to enter to IN-START LG OLED TV Service Menu.

There several methods to access the Service Menu here, or you can buy the LG Service Menu Remote Control from eBay; search for 'MKJ39170828' Remote.

It can be used also the AnyMote App from any smartphone equipped with build-in IR transmitter.



Use the IN-START button to access the LG OLED TV Service Menu, it will ask for a password, type '0413', navigate to '13. OLED', and set the TCP to Off '0'.

Its recommended to check if the TCP setting will stay at '0' (Off) after you will install a newer LG OLED TV Firmware Update or when you will perform reset to factory default settings (Reset to Initial Settings).
 

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Discussion Starter #280
LG Video Signal Processing Pipeline Info

LG 2018/2019 OLED image processing chain seems to be:



HDMI Input Signal -> Contrast / Brightness -> 3D LUT -> 1D LUT -> 3x3 Matrix - 1D LUT -> 1D LUT -> OLED Light -> Display Panel.

There 3x1D LUTs (1024-Point) one for each Red, Green and Blue channel. (Red 1D LUT Box of the video chain diagram)

After the 3D LUT (we can upload), there is a De-Gamma 1D LUT (un-does the default gamma by applying reverse gamma values) followed by a 3x3 Matrix (for color transform) followed by a Re-Gamma 1D LUT (it will re-apply the default gamma) followed by the 1D LUT (we can upload).

The 3x3 Matrix can be used for linear scale color transformation between different colorspaces. Its a simple mathematical formula that can reposition, rotate, and scale, so describing the global size/position of the gamut, but not manage the internal (volumetric) content in a non-linear fashion.

De-Gamma LUT, 3x3 Matrix and Re-Gamma LUT are disabled by loading UNITY values during the Reset LUT procedure of LG Template with DeviceControl.

Also OLED Light is an OLED Panel gain control and is separate from the video signal path.

The TV's Video Signal Pipeline needs to minimize image artifacts due to rounding errors and image gradation errors; from colorspace conversions/processing etc.

For that reason, the bit-depth of the 3D and 1D LUT's in the signal pipeline should be at least 2 bits greater than the video input, and the bit depth of the signal processing should be at least 2 bits greater than that of the LUT's.

Because the diagram above designed without having access to the exact video pipeline diagram from any LG Engineer, some additional processing steps are missing from the diagram picture.

For example, the 3x3 matrix conversion of YCbCr to RGB before data will enter the LUT's stages, the Input Range Mapping (LG TV Black Level Control), the RGB to YCbCr 3x3 matrix for internal calibration controls adjustments.

For some internal calibration controls; like CMS adjustments of Hue/Saturation/Luminance; the video processing operations must be performed in a linear luminance domain, in a YCbCr colorspace with one luminance and two color difference channels.

According to that way the 1D LUT is implemented in the LG OLED TV, you must do the 1D LUT first, and then the 3D LUT profiling. If you change the 1D LUT you must re-do the 3D LUT. But if you change the 3D LUT only, you don't need to re-do the 1D LUT.

As the 3D LUT is placed before other LUT's and other adjustment stages (like White Balance when internal 1D LUT capability will not be used), this means that 3D LUT can be properly calibrated only after the calibration of all other stage adjustments (Internal 1D LUT or White Balance when internal 1D LUT will not be used) has been completed.

For the internal 1D LUT to work as expected; because the Contrast/Brightness controls are located before the 1D/3D LUT tables; set Contrast @ 85*, Brightness @ 50 and Color @ 50 value settings. (* additionally, it will be described a profiling method which will work by setting Contrast @ 100 also, but it will clip 'headroom').

When Internal 1D+3D LUT capabilities are used, normal menu settings (White Balance, Color Temperature, Gamma, Color Gamut and Color Management System) are disabled, even service menu calibration values are bypassed, the panel will have native 10000K color temperature and ~2.2 Gamma response.

The normal TV menu picture mode settings: Contrast, Brightness, Color and Tint should stay at default values (these are the bypass processing values) because they are positioned before the 3D/1D LUT tables.

OLED Light can be adjusted to reach the target luminance level during pre-calibration procedure but not adjust it after the profiling or when any 1D/3D correction LUT has been uploaded internally to the TV.

The LG 2018 C8/E8/G8/W8 OLED TV's use the Alpha 9 processor while the LG B8 is equipped with the Alpha 7 processor. (LG 2017 models had Alpha 7)

Both processors (α7/α9) have quad cores (CPU) running at 1.008 GHz frequency. The graphics processor has dual cores (GPU) running at 700 MHz frequency. Each processor has the same built-in 8 GB DDR4 ROM eMMC flash memory. But α9 has 3 GB DDR4 RAM while α7 has 2GB DDR4 RAM.

In terms of their technical characteristics, the processors are almost the same and use the same cores of the main and graphics processor. Of course, it may be that in α9 cores of a newer generation are used. But most likely, the difference between processors in the amount of RAM.

As different image processor used, this also affects some other processing techniques such as Sharpness and Depth Enhancements. The LG 2018 C8/E8/G8/W8 have a Frequency-based Sharpness Enhancer, in addition to Object-based Depth Enhancer while the LG B8 utilizes a standard Sharpness Enhancer, and Edge-based Depth Enhancer. These picture enhancements do not need to be used when watching high quality content, so the advantage of LG C8/E8/G8/W8 have over the LG B8 is limited only to low resolution/quality sources.
 
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