REC 709 calibration

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This topic contains 21 replies, has 2 voices, and was last updated by  Florian Höch (@fhoech) 4 months ago.

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  • #15680

    darklight (@darklight)
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    Hi guys. im really new to this. Im currently working on an indy film and hoping i could setup a small color grading suite in my home.  Its my first time to calibrate and i just recently purchases a spyder 5 elite and hve tried using the spyder software using  rec 709 calibration setting. Somehow the colors feel way off.I already downloaded displaycal, and have tried calibrating more than 5 times with it and just recently i found out i needed to uninstall my spyder software first. I now uninstalled it and currently doing another calibration w a newly re-install displaycal again.

    Anyway so far from all the 5 installations, theyve been giving me similar results.

    Settings are:

    –   video  3dLut – for resolve (d65) rec 709/ rec 1886

    set at White led

    auto correction and patches are set to about half the bar of about 2 hours and a half.

    White and black compensations off

    so far ive hit monitor measurements correctly in terms of monitor rgb and brightness control are on point.

    i recently got this Viewsonic VP 2468 w/c is pretty good accurate IPS color monitor for a small budget

    https://www.monitornerds.com/viewsonic-vp2468-review/

    im using a macbookpro 15 inc touchbar i7 late 2018 w the latest videocards

    with a black magic ultrastudio mini monitor attached to the external monitor

    The problem im getting is that my external monitor seems calibrated based on the reports and ive also matched my laptop to it using the same settings.

    BUT whenever i deliver an export of h264 or proress files, the contrast becomes too much and the blacks are too crushed.  it seems that my default COLOR lcd profile in ky laptop seems to be closer in terms of gamma and blacks on every exported (rendered) output file i make.

    Im trying to figure out if its maybe a wrong calibration since the renders are all set on default so theres no way im putting anything on the files on my renders.

    And somehow the gamma seems closer to the default profile of the laptop.

    the contest of my calibrated external and laptop matches but both of them totally lessened in terms of contrast once the displaycal LUT was applied.

    Is there anything i might be missing or something im doing wrong?

    ive calibrated 5 times and get the same results on them which means the calibrations seem ok.

    also ive followed instructions from here:

    any help or input would greatly help. thank you so much

    Jay

    #15684

    Florian Höch (@fhoech)
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    Hi,

    near black contrast will always be reduced by BT.1886 on contrast-limited LCD displays, this is intended. On cheap displays, you may be better off calibrating to gamma 2.2 or 2.4 (set gamma to relative and black output offset to 100%) if your goal is to better match (e.g.) an uncalibrated display/TV.

    #15685

    darklight (@darklight)
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    thank you so much for the reply.  Do i need to re calibrate from scratch to set it to 2.2. or can i just create a new 3d LUT via displaycal and adjust the tonal curve to gamma 2.2?  thanks again

    #15686

    darklight (@darklight)
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    also if i may ask, how do i do  a black offset to 100%.  I assume the relative gamma is  adjusted thru the “RENDERING INTENT” in the 3d lut settings?   sorry if im really not an expert at this.  Thanks again ahead

    #15687

    darklight (@darklight)
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    thank you so much for the reply.

    1. Do i need to re calibrate from scratch to set it to 2.2. or can i just create a new 3d LUT via displaycal and adjust the tonal curve to gamma 2.2
    2. also if i may ask, how do i do  a black offset to 100%.
    3. I assume the relative gamma is  adjusted thru the “RENDERING INTENT” in the 3d lut settings?   sorry if im really not an expert at this.  Thanks again ahead

    thanks so much

    #15688

    darklight (@darklight)
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    figured out the relative setting and black offset. i guess ill just restart the calibration to be sure. thanks a lot. I didnt touch the rendering intent anymore .

    #15689

    Florian Höch (@fhoech)
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    No need to take new measurements, you can just create a new 3D LUT with the new settings.

    #15690

    darklight (@darklight)
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    thank you! its a good match to my renders now 🙂 i guess when i upgrade monitor ill resort back to absolute and remove the offset.  Thanks again

    #15814

    darklight (@darklight)
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    Hi Florian, going back to my original question, ive  actually set my calibration to 2.2 gamma . relative.  black output offset 100%

    Ive recently asked a friend from a huge local post house grading facitlity here using a greyscale chart to send me a file exported in resolve while placing the white to exactly 1023 ire and the the pure black at 0 ire so that i can base if we have the same gamma.

    Upon checking, my whites are exactly 1023 as they have but my blacks are a little too deep and lower than 0 on the 2.2 gamma calibration.

    I tried creating a custom 2.0 gamma calibration and so far thats what matches to the post house .

    Is there a posiblity that this is caused by my monitor’s capability on the black levels.? Did i do the right thing by checking into the greyscale of the post house who i assume is well calibrated. they cater to big ads and movies locally. Right now, ive set my calibration on 2.0 for resolve. I assume the greyscale file is a good basis for me to check my gamma calibration. Let me know if thats ok ?

    also im assuming if i upgrade to  a good monitor for grading, would that change the gamma settings?

    thank you so much

    Attachments:
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    #15844

    Florian Höch (@fhoech)
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    The file attached looks like a “pluge” style pattern. This can be used to set the black level before doing any measurements. It won’t help you setting gamma.

    #16904

    darklight (@darklight)
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    Just got a new Eizo CG 2420 and done the usual corrections with my new i1 display pro. I use a black magic ultra mini display to patch to the reference monitor.

    THey say theres a correction needed for the EIZO cg2420?  Should I still go for relative and a black output offset of 100?

    it seems that my delivery outputs in resolve are a lot less contrasty than my eizo cg 2420 . Should i adjust to absolute? Sorry

    I mean i wish i could learn that proper ways of doing this . Im trying to also see if theres an online course i can take to properly

    learn the art of calibration. I really want to get the picutre right. Thank you so much for the support.  I hope you can help

    me with this.

    i1Display Pro on Amazon  
    Disclosure: As an Amazon Associate I earn from qualifying purchases.

    #16905

    darklight (@darklight)
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    Just to let you know i usually output for tv broadcast and  web. I assume the rec 709 space would be a good space to work with.

    I just want to know when to go absolute or relative. or why or when do i need to do the black output offset for calibration.

    Also my eizo cg2420 seems a little more reddish than the final output. I hope theres a right correction file to download. thanks

    #16917

    Florian Höch (@fhoech)
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    Eizo CG2420 should have a PFS Phosphor WLED backlight, the correction to use is “Spectral: Panasonic VVX17P051J00”.

    “Absolute colorimetric with whitepooint scaling” as in rendering intent for 3D LUT, will make the 3D LUT match the source whitepoint (i.e. D65 equivalent for Rec. 709) and is generally the correct choice (default).

    “Absolute” vs “Relative” gamma affects if you are using an absolute (“technical”) gamma value, which may result in a different relative (“effective”) gamma, or relative (“effective”), which makes 50% input result in exactly the chosen gamma when measured (but technical gamma will be different to achieve this). BT.1886 uses an “absolute” gamma value with no black output offset, i.e. effective gamma will vary depending on display black level. On a LCD with high black level, it may be better to choose 100% black output offset.

    #16918

    darklight (@darklight)
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    Thank you Florian! ill use that correction and settings.  There are two of those Spectral: Panasonic VVX17P051J100 corrections and i chose the most recent one. The one with the 3nm

    I really appreciate the help

    #16919

    Florian Höch (@fhoech)
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    There are two of those Spectral: Panasonic VVX17P051J100 corrections

    Check the filename. The correct one will either have “Panasonic VVX17P051J00.ccss” or “PanasonicVVX17P051J00.ccss”, and both are the same original X-Rite EDR with 1nm resolution (351 bands).

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