Discussion in 'Article Discussion' started by bit-tech, 11 May 2018.
It doesn't look like VESA are publishing a list of colourimeters to use with this. For home use, this could end up being a massive gotcha: regular tristimulus colourimeters that you would use to calibrate your existing sRGB (or AdobeRGB) panels are NOT suitable here. A tristimulus colourimeter works by measuring the light levels of certain specific wavelengths of light using notch filters, and uses the wavelengths defined in the sRGB specs. Rec.2020 defines a different set of primaries, so the filters will be measuring the light level off to the edge of the actual emitted spectrum. This could result in having a device that perfectly conforms to the DisplayHDR specs, but 'fails' when you test it using an sRGB colourimeter because it measures a value less than the real peak value. Or worse: companies could start to 'cheat' the specs by using backlights that conform to the sRGB primaries rather than the Rec.2020 primaries: these would 'pass' the test with an sRGB colourimeter with flying colours, but look completely wrong in reality.
::EDIT:: You cannot just use "multiply by 1.25x" or similar as a 'compensation factor', as you do not know in advance the spectrum of the primaries used in any particular monitor.
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