How to get Color Space Gamut on TVs

Home Forums Help and Support How to get Color Space Gamut on TVs

Viewing 15 posts - 1 through 15 (of 42 total)
  • Author
    Posts
  • #35894

    Lenk83
    Participant
    • Offline

    Hi there

    i want to test some aspects of TVs and Displays OLED and LCD as well. For me it is about how good is a TV/Screen calibrated with all its modes by factory default. I want a easy to use solution and used HCFR so far. But it lacks of measuring the color space gamut.

    Color Space Gamut for rec 709 and rec 2020 / p3 in percentage
    Color Accuracy for rec 709 and rec 2020 in Delta E
    Contrast Ratio for OLED and LCD Displays (On/Off and Ansi)
    Maximum Brightness of SDR and HDR Content

    I use x-Rite One Studio and have a Spyder X Pro as well.
    Can you tell me, if there is a possibility to get a percentage of the targeted color space gamut with DisplayCAL, for example rec.709?

    How I would use it:

    • Choose the display, Instrument, Mode is LCD generic, no correction
    • Go to verification and choose a pattern, simulated profile, and actual settings, Tone curve unmodified and then start with measurement report.

    SpyderX Pro on Amazon  
    Disclosure: As an Amazon Associate I earn from qualifying purchases.

    #35902

    Vincent
    Participant
    • Offline

    I use x-Rite One Studio and have a Spyder X Pro as well.
    Can you tell me, if there is a possibility to get a percentage of the targeted color space gamut with DisplayCAL, for example rec.709?

    Set all “calibration tab” settings to native/as measured, then make a profile (which won’t store GPU grey calibration)

    After calibration profile will report 3 typical coverages (sRGB/AdobeRGB/P3), for arbitrary colorspace comparison check iccgamut & viewgam:

    Reply To: Gamut Display Error or Scam ?

    How I would use it:

    • Choose the display, Instrument, Mode is LCD generic, no correction

    Then all measurements will be wrong and your tasks pointless. Guess correction by primaries or labeled backlight tech or check community database

    https://colorimetercorrections.displaycal.net/

    • Go to verification and choose a pattern, simulated profile, and actual settings, Tone curve unmodified and then start with measurement report.

    You’ll need to add “use simulate profile as display profile” for factory calibration validation, otherwise you’ll testing behavior un der color managed apps.

    #35920

    Lenk83
    Participant
    • Offline

    Allright

    But sorry for being a little unexperienced, but I have no clue which correction to make. For example I have here a LCD LED Panasonic. The website you posted (thanks for that) showed up several Panasonic, and I have no idea which is the right one.

    https://colorimetercorrections.displaycal.net/?get&type=ccmx&manufacturer_id=MEI&display=Panasonic-TV&instrument=i1%20DisplayPro%2C%20ColorMunki%20Display&html=1

    Automatic corrections won’t make it better I guess?

    Second question:  On “Validate” which Tone Curve do I have to pick? Unchanged, Offset or the right Gamma Setting fitting the TV settings in order to fit my purpose?

    #35921

    Vincent
    Participant
    • Offline

    Allright

    For example I have here a LCD LED Panasonic.

    Manufacturer name  is useless, it’s the model.

    The website you posted (thanks for that) showed up several Panasonic, and I have no idea which is the right one.

    https://colorimetercorrections.displaycal.net/?get&type=ccmx&manufacturer_id=MEI&display=Panasonic-TV&instrument=i1%20DisplayPro%2C%20ColorMunki%20Display&html=1

    The same model as the device you are measuring. If not present guess by native primaries, review, spec… or rent an spectrophotometer

    Automatic corrections won’t make it better I guess?

    No

    Second question:  On “Validate” which Tone Curve do I have to pick? Unchanged, Offset or the right Gamma Setting fitting the TV settings in order to fit my purpose?

    Whatever that display (or an OSD preset with a factory calibration)  is meant to be

    #35930

    Lenk83
    Participant
    • Offline

    It’s a LXW944, Panasonic calls it Core LED. No reviews yet, it’s too new. Guess by presets? I have to google what you mean by that …

    second thing: I get bad contrast ratio with about 980:1. No matter which settings I put on the TV. Can that have something to do with failing the correction?

    #35931

    Vincent
    Participant
    • Offline

    It’s a LXW944, Panasonic calls it Core LED. No reviews yet, it’s too new. Guess by presets? I have to google what you mean by that …

    Guess by primaries in native setting (or biggest gamut setting)

    Example: if primaries are P3 or close to that… it cannot be a White LED which are sRGB-like

    Sicne it’s a new TV, very likely to be P3-like and have some of these backlights:

    -WLED PFS 9x % P3 => WLED PFS correction
    -QLED or nano IPS variants => QLED correction
    which one… I cannot tell unless you read its spectral power distribution with an spectrophotometer, or find a review that has done that and plot it on an image.

    Make sure to disable ambient light corrections in TV for measurement.

    second thing: I get bad contrast ratio with about 980:1. No matter which settings I put on the TV. Can that have something to do with failing the correction?

    No, correction cannot change such things. In the end it’s a constant matrix (3×3) multiplying measured coordinates (vector 3, variable)

    If you want an easier explanation, correction changes a little, minimal primaries and changes whitepoint. that’s all. no contrast, gamma or grey balance variations.

    • This reply was modified 1 month, 1 week ago by Vincent.
    #35933

    Lenk83
    Participant
    • Offline

    For color accuracy this is what I did now:

    • Set to Cinema Pro Modus on TV
    • Set to Gamme Rec1886 on TV
    • Set Color Gamut on Rec2020 on TV
    • Display Cal: Correction LCD PFS LED, advanced testform 51 patches, simulationprofil DCI P3, simulation as display profile, gamma rechts 1886.

    Result is averge dE 3,49 . Do you think it is a plausible result?

    Attached the report for problem analyses.

    Attachments:
    You must be logged in to view attached files.
    #35935

    Vincent
    Participant
    • Offline

    Rec1886 gamma vs input plot depends on contrast by definition. You do not want that on a low contrast display like a typical IPS.

    Display looks like gamma 2.2 from measurements. Also that profile you chose as target is not meant for home displays (WP), you can choose its D65 variant.

    All other settings seem a sensible guess without spectral data to confirm colorimeter correction. Maybe your TV is too dim but IDNK the ambient light in your room, usually for a LED (non OLED) displays on a bright room with windows they are pushed over 200cd/m2 but it depends on ambient light and your personal taste, it’s not set on stone.

    #35936

    Lenk83
    Participant
    • Offline

    Ok im getting desperate.

    I tested a very cheap LCD TV versus expensive LG OLED too.

    Both get nearly same results (1,7-1,8 average deltaE). Tried different corrections, different gamma settings, nothing helped. Corrections have a slight impact of 0,5 dE it seems. This just can’t be. Looking at the cheap TV the colors has to be dE 10 or something, really pale, no intensity, no accuracy at all.

    What do I miss?

    #35937

    Lenk83
    Participant
    • Offline

    Auto Brightness, Auto Backlight etc is disabled. If you mean that.

    #35938

    Vincent
    Participant
    • Offline

    We do not know all the mistakes you made/may have made…

    #35939

    Vincent
    Participant
    • Offline

    Corrections have a slight impact of 0,5 dE it seems. This just can’t be.

    It can be if your colorimeter firmware says that your unit is a very good match to CIE 1931 2degree.

    CCSS auto correct device measurements in sofware, if needed where (wavelength) needed, although in a compact way (a 3×3 matrix) since device cannot output spectral data.

    • This reply was modified 1 month, 1 week ago by Vincent.
    #35946

    Lenk83
    Participant
    • Offline

    I mean, the results overall can’t be. dE of a real bad TV compared to a high end OLED are to similar , see above.

    To see my eventual mistakes I described what i did. and posted report. Is there any detailed Manuel for my purpose, I mean, step by step?

    #35947

    Raj S
    Participant
    • Offline

    Use this guide for TV calibration: https://www.lightillusion.com/colourspace_zro_guide.html

    It’s for a paid software called LightSpace. Just ignore it and use HCFR instead. It explains the general concepts, what to do, in what order etc. Like for example which TV settings to change and what to measure.

    In HCFR go to Advanced > Preferences > References. Make sure Rec709 is selected. For gamma select BT.1886 and put “Effective @50%” as 2.2 and “% input offset” at 0%. Now go to Advanced tab and put “Color Difference Formula” to CIE2000 and “Gray Scale dE handling” to “Absolute Y w/ gamma”.

    We will do SDR mode first. Put into Movie mode. Reset your settings. Then turn all dynamic processing off. Set the Gamma slider to closest to 2.2 (“Measure gray scale” in HCFR to see it on the chart). Now calibrate 2 point White Balance and then 10 point White Balance. After that you can either leave Color Space on Auto or calibrate it manually to Rec709.

    Also, I recommend NOT doing HDR. If you want to, only calibrate the HDR 2 point White Balance and Gamma slider. Make sure all image processing is off for HDR. That’s the easiest solution.

    Remember, check the guide!! It explains what I said but in a easy way!

    #35948

    Lenk83
    Participant
    • Offline

    Thank you for the reply. The guide you mentioned is for calibration. I want to measure without calibration.

    But basically what I did is, what you said:

    • Ref rec709
    • gamma BT1886, Effective 50%, 2.2 and %input offset at 0%
    • Color Formula CIE2000
    • Gray Scale dE Handling Absolute Y w/gamma

    That worked most of the time. But by now, I want to measure the gamut. For that I switched to display cal, which is capable of, what hcfr is not.

    The results on red.709 with similar settings are pretty similar. Only DCI P3 is pretty bad, UHDA P3 even worse!

    I come to the conclusion, that the Laptop which is connected to the TV does not activate the HDR mode on the TV, so UHDA or DCI P3 or whatever HDR color I set, will be measured with rechtzeitig 709. So that would explain, why every TV, no matter if an wide gamut TV or a cheap 400 Euro TV, is getting similar results on this one.

    Anyone knows about these issues, putting display cal, Laptop and TV together? Even tried to put Windows to HDR mode which did not seem to make it better…

Viewing 15 posts - 1 through 15 (of 42 total)

You must be logged in to reply to this topic.

Log in or Register

Display Calibration and Characterization powered by ArgyllCMS