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Because wide gamut (and better than 100 cd/m²) displays have been around for more than a decade now - (though IIRC none - aside for black & white medical monit

Because wide gamut (and better than 100 cd/m²) displays have been around for more than a decade now - (though IIRC none - aside for black & white medical monitors - had better than 8 bit per color in hardware until "HDR in screens" showed up - IIRC also the PlayStation 3 and some games had a 10 bit per color mode that caused a lot of compatibility problems for hardly any benefit ?) - but (non-Apple) OS support has been abysmal until recently, and you probably need to pay a technician to use a probe to calibrate your screen anyway, so only some work environments would bother to set them up correctly ? ---- [1] Dolby PQ only needs 12 bits for up to 10k cd/m² ? https://www.avsforum.com/threads/smpte-webinar-dolby-vision-pq-eotf.1533447/ https://www.avsforum.com/threads/smpte-webinar-dolby-vision-...

formerly_proven 5y ago
There's "30 bit" (10 bpc) displays, which have been around for a fairly long time. These are not HDR, but usually native AdobeRGB with high bit depth. The way that works / used to work is that when an application uses a 30 bit surface, it still outputs an 8 bit image which travels through the Windows GUI pipeline and it's the graphics driver which replaces it with the real 10 bit image on scanout. I don't think any of the current TN/IPS/etc. PC monitors with HDR have 10 bit panels. HDR is achieved generally through sheer imagination (most) and less commonly through more or less (rare) rough local dimming, not by actually having a panel capable of anything close to HDR contrast ratios.
- BlueTemplar 5y ago
  And were those 10 bit per color in hardware ? Also, all of this is about liquid crystals (and the electronics controlling them), but cathode ray tubes, plasmas, and light emitting diodes have quite different characteristics... I would be surprised if nobody had made yet (professional ?) non-CRT PC monitors capable of more than 256 values discrimination ?! (Not even Apple ?!? Or at least some super-expensive, but still commercial (= non-experimental) displays ?) Also, I guess a similar benefit might be achieved by using more than 3 primaries : who was it already that used a 4th "yellow" subpixel in their (IIRC) diode displays ? (Though it's still not clear to me why more displays aren't using the standard (at least in Charge Coupled Devices) 2x2 Bayer Filter with double green, rather than a 3x1 one ? Too much reliance on Windows' ClearType hack working properly ? But why in TVs too ??)
  - formerly_proven 5y ago
    > And were those 10 bit per color in hardware? Yes > I would be surprised if nobody had made yet (professional ?) non-CRT PC monitors capable of more than 256 values discrimination ?! (Not even Apple ?!? Or at least some super-expensive, but still commercial (= non-experimental) displays ?) They exist, but it's limited to the high-end. E.g. Apple's XDR display has a 10-bit panel and FALD. Reference-class monitors are generally of the "dual film" type, which essentially means that the panel is two LCDs on top of each other, one being used to control only brightness of a given pixel, and the other for brightness and color. > (Though it's still not clear to me why more displays aren't using the standard (at least in Charge Coupled Devices) 2x2 Bayer Filter with double green, rather than a 3x1 one ? Too much reliance on Windows' ClearType hack working properly ? But why in TVs too ??) Non-standard pixel layouts are common in OLEDs, e.g. RGBW, weird pyramids and un-even subpixel sizes (I'm assuming due to differing phosphor efficiencies). These all lead to poor text and UI clarity, as one would expect. (It's worth pointing out that OLEDs, being LEDs at their heart, have inherently lacking linearity which is why most of their brightness range is covered by digital modulation) RGB subpixels require the fewest number of subpixels, which also means reduced brightness loss due to LCD structures. Going to Bayer would mean 33 % more pixels for the same display, except it's dimmer (increasing pixel pitch by 50 % horizontally does not make up for halving it vertically), more expensive to make and also dimmer because now you have two green dots per pixel, so they need to be half as bright, throwing away more of the backlight, and the drivers now need to perform with inhomogenous pixels -- without an obvious upside. The reason color camera sensors tend to use Bayer filters is - I think - because green contributes most to perceived brightness, so doubling the sensor area for green means halving green's contribution to luma noise. This problem does not exist in displays.
    - BlueTemplar 5y ago
      What backlight is even linear though ? IIRC cathode rays aren't. Plasma-fluorescent ? Are liquid crystals even used in big screens with something else than a diode backlight these days ? (Maybe cheap ones still use plasma-fluorescent ?) ---- Ooh, right, silly me, for displays green light being human-efficient is backwards ! So you need less than 1/3 of green subpixels, rather than more ! (Anyone tried that yet ?)

formerly_proven 5y ago

There's "30 bit" (10 bpc) displays, which have been around for a fairly long time. These are not HDR, but usually native AdobeRGB with high bit depth. The way that works / used to work is that when an application uses a 30 bit surface, it still outputs an 8 bit image which travels through the Windows GUI pipeline and it's the graphics driver which replaces it with the real 10 bit image on scanout. I don't think any of the current TN/IPS/etc. PC monitors with HDR have 10 bit panels. HDR is achieved generally through sheer imagination (most) and less commonly through more or less (rare) rough local dimming, not by actually having a panel capable of anything close to HDR contrast ratios.

BlueTemplar 5y ago
And were those 10 bit per color in hardware ? Also, all of this is about liquid crystals (and the electronics controlling them), but cathode ray tubes, plasmas, and light emitting diodes have quite different characteristics... I would be surprised if nobody had made yet (professional ?) non-CRT PC monitors capable of more than 256 values discrimination ?! (Not even Apple ?!? Or at least some super-expensive, but still commercial (= non-experimental) displays ?) Also, I guess a similar benefit might be achieved by using more than 3 primaries : who was it already that used a 4th "yellow" subpixel in their (IIRC) diode displays ? (Though it's still not clear to me why more displays aren't using the standard (at least in Charge Coupled Devices) 2x2 Bayer Filter with double green, rather than a 3x1 one ? Too much reliance on Windows' ClearType hack working properly ? But why in TVs too ??)
- formerly_proven 5y ago
  > And were those 10 bit per color in hardware? Yes > I would be surprised if nobody had made yet (professional ?) non-CRT PC monitors capable of more than 256 values discrimination ?! (Not even Apple ?!? Or at least some super-expensive, but still commercial (= non-experimental) displays ?) They exist, but it's limited to the high-end. E.g. Apple's XDR display has a 10-bit panel and FALD. Reference-class monitors are generally of the "dual film" type, which essentially means that the panel is two LCDs on top of each other, one being used to control only brightness of a given pixel, and the other for brightness and color. > (Though it's still not clear to me why more displays aren't using the standard (at least in Charge Coupled Devices) 2x2 Bayer Filter with double green, rather than a 3x1 one ? Too much reliance on Windows' ClearType hack working properly ? But why in TVs too ??) Non-standard pixel layouts are common in OLEDs, e.g. RGBW, weird pyramids and un-even subpixel sizes (I'm assuming due to differing phosphor efficiencies). These all lead to poor text and UI clarity, as one would expect. (It's worth pointing out that OLEDs, being LEDs at their heart, have inherently lacking linearity which is why most of their brightness range is covered by digital modulation) RGB subpixels require the fewest number of subpixels, which also means reduced brightness loss due to LCD structures. Going to Bayer would mean 33 % more pixels for the same display, except it's dimmer (increasing pixel pitch by 50 % horizontally does not make up for halving it vertically), more expensive to make and also dimmer because now you have two green dots per pixel, so they need to be half as bright, throwing away more of the backlight, and the drivers now need to perform with inhomogenous pixels -- without an obvious upside. The reason color camera sensors tend to use Bayer filters is - I think - because green contributes most to perceived brightness, so doubling the sensor area for green means halving green's contribution to luma noise. This problem does not exist in displays.
  - BlueTemplar 5y ago
    What backlight is even linear though ? IIRC cathode rays aren't. Plasma-fluorescent ? Are liquid crystals even used in big screens with something else than a diode backlight these days ? (Maybe cheap ones still use plasma-fluorescent ?) ---- Ooh, right, silly me, for displays green light being human-efficient is backwards ! So you need less than 1/3 of green subpixels, rather than more ! (Anyone tried that yet ?)