5 ms·

Another good introduction to wide gamut and HDR is this talk about HDR in Krita from LGM 2019: https://www.youtube.com/watch?v=5MrocfwJd4k https://www.youtube.c

Another good introduction to wide gamut and HDR is this talk about HDR in Krita from LGM 2019: https://www.youtube.com/watch?v=5MrocfwJd4k https://www.youtube.com/watch?v=5MrocfwJd4k There, the main focus is on very bright shades (whiter than white), but highly saturated colors are in scope as well. I definitely appreciate the work to enable this, but honestly remain skeptical how important it is. I mean, sRGB #FF0000 is a pretty bright red. When do you really need more than that?

bscphil 5y ago
> I mean, sRGB #FF0000 is a pretty bright red. When do you really need more than that? I mean, sometimes you do. Especially when you're working with canvases. But I fear this will just be abused: what advertiser isn't going to want the brightest possible red in the gamut of the user's screen, instead of just the brightest possible red in sRGB?
sp332 5y ago
If you look at the color space diagrams, #FF0000 isn't super ultra red. If your monitor is showing it that way, maybe it's miscalibrated, and inaccurately showing a brighter red than is actually encoded in the file?
- jacobolus 5y ago
  > #FF0000 isn't super ultra red ... you mean, because it is super ultra orangish red? Your display’s version of FF0000 is literally the most intense vaguely red type of color that it can produce. Some standard RGB space’s version of FF0000 is literally the most intense vaguely red type of color that it can represent. The sRGB version is so colorful that it should be avoided for most practical purposes. Forget about ever putting the P3 version of FF0000 on screen, unless you hate your audience. Or do you just mean it’s less intense than e.g. a laser pointer?
  - sp332 5y ago
    literally the most intense vaguely red type of color that it can produce It's not, because we're talking about #FF0000 in a specific color space. Most monitors these days can go well beyond sRGB's version of red, but you have to have some way to express that through the software to the monitor. This shouldn't just be the brightest red your display can show, unless you calibrated it that way on purpose.
    - jacobolus 5y ago
      By chopping “Your display’s version of FF0000” out of your quotation, you dropped the whole point of the sentence, which is about the native RGB space of your display. That some displays have a narrower-spectrum (and therefore more colorful) “R” primary than the sRGB spec is literally the premise of this conversation, and is understood by everyone here. But the sRGB spec’d primary is still extremely intense, beyond the practical needs of any user interface and the vast majority of images/videos.
jacobolus 5y ago
The FF0000 part of the wider gamut is pretty useless per se, but widening the gamut also gives you a lot of nice non-eye-bleeding colors in other areas. RGB gamuts are very limited in light red, dark yellow, light and dark teal, etc. colors. The main downside is that as gamuts get expanded via narrower-spectrum primaries, there is an increasing risk of inter-observer variability (I also wonder if they may cause more eye strain, have worse effects on sleep cycles, ...). A better solution than the current trend of wide gamuts made by 3 primaries with very narrow spectra would be displays with 6+ primaries, but that takes a much more dramatic redesign of the last few stages of the graphics pipeline, a more dramatic hardware redesign, and potentially different content to really show off (content that will moreover be really hard to effectively show on older displays). I’m still hoping it happens within the next couple decades, but I wouldn’t hold my breath. If you know the shape of common RGB gamuts, you’ll start to notice how much all of our RGB-displayed visual media is constrained and nudged toward particular choices. There are e.g. color choices made in some paintings that can’t be effectively used in films. There are plenty of physical scenes that can’t be effectively reproduced. And on the flip side, areas of the RGB gamut where there is more available contrast get used a lot, even when they don’t quite fit the mood.
- modeless 5y ago
  I've never seen a wide gamut demo that was impressive to me. High frame rate yes, high contrast/brightness for HDR yes, those are definitely worthwhile. But wide gamut just doesn't seem to make a big difference to justify the implementation cost. I'd love to see some content that would justify wide gamut for me. Any suggestions?
  - bloak 5y ago
    I think it would only be useful if the colours on the screen have to match colours off the screen. If all you're paying attention to is what's on the screen then it probably doesn't matter much exactly what those colours are because it's all relative, your brain compensates for it, and it's not as if the cells in your eye have a consistent response to colour in any case: it all depends on what you've been looking at recently. If you've ever been in a television shop, back when they still had shops, you could find two screens next to each other showing the same television channel but with radically different colours, when you compare them side-by-side, but if you watch just one of the screens - it doesn't matter which - you get used to the colours of that screen and everything looks fine.

bscphil 5y ago

> I mean, sRGB #FF0000 is a pretty bright red. When do you really need more than that? I mean, sometimes you do. Especially when you're working with canvases. But I fear this will just be abused: what advertiser isn't going to want the brightest possible red in the gamut of the user's screen, instead of just the brightest possible red in sRGB?

sp332 5y ago

If you look at the color space diagrams, #FF0000 isn't super ultra red. If your monitor is showing it that way, maybe it's miscalibrated, and inaccurately showing a brighter red than is actually encoded in the file?

jacobolus 5y ago
> #FF0000 isn't super ultra red ... you mean, because it is super ultra orangish red? Your display’s version of FF0000 is literally the most intense vaguely red type of color that it can produce. Some standard RGB space’s version of FF0000 is literally the most intense vaguely red type of color that it can represent. The sRGB version is so colorful that it should be avoided for most practical purposes. Forget about ever putting the P3 version of FF0000 on screen, unless you hate your audience. Or do you just mean it’s less intense than e.g. a laser pointer?
- sp332 5y ago
  literally the most intense vaguely red type of color that it can produce It's not, because we're talking about #FF0000 in a specific color space. Most monitors these days can go well beyond sRGB's version of red, but you have to have some way to express that through the software to the monitor. This shouldn't just be the brightest red your display can show, unless you calibrated it that way on purpose.
  - jacobolus 5y ago
    By chopping “Your display’s version of FF0000” out of your quotation, you dropped the whole point of the sentence, which is about the native RGB space of your display. That some displays have a narrower-spectrum (and therefore more colorful) “R” primary than the sRGB spec is literally the premise of this conversation, and is understood by everyone here. But the sRGB spec’d primary is still extremely intense, beyond the practical needs of any user interface and the vast majority of images/videos.

jacobolus 5y ago

The FF0000 part of the wider gamut is pretty useless per se, but widening the gamut also gives you a lot of nice non-eye-bleeding colors in other areas. RGB gamuts are very limited in light red, dark yellow, light and dark teal, etc. colors. The main downside is that as gamuts get expanded via narrower-spectrum primaries, there is an increasing risk of inter-observer variability (I also wonder if they may cause more eye strain, have worse effects on sleep cycles, ...). A better solution than the current trend of wide gamuts made by 3 primaries with very narrow spectra would be displays with 6+ primaries, but that takes a much more dramatic redesign of the last few stages of the graphics pipeline, a more dramatic hardware redesign, and potentially different content to really show off (content that will moreover be really hard to effectively show on older displays). I’m still hoping it happens within the next couple decades, but I wouldn’t hold my breath. If you know the shape of common RGB gamuts, you’ll start to notice how much all of our RGB-displayed visual media is constrained and nudged toward particular choices. There are e.g. color choices made in some paintings that can’t be effectively used in films. There are plenty of physical scenes that can’t be effectively reproduced. And on the flip side, areas of the RGB gamut where there is more available contrast get used a lot, even when they don’t quite fit the mood.

modeless 5y ago
I've never seen a wide gamut demo that was impressive to me. High frame rate yes, high contrast/brightness for HDR yes, those are definitely worthwhile. But wide gamut just doesn't seem to make a big difference to justify the implementation cost. I'd love to see some content that would justify wide gamut for me. Any suggestions?
- bloak 5y ago
  I think it would only be useful if the colours on the screen have to match colours off the screen. If all you're paying attention to is what's on the screen then it probably doesn't matter much exactly what those colours are because it's all relative, your brain compensates for it, and it's not as if the cells in your eye have a consistent response to colour in any case: it all depends on what you've been looking at recently. If you've ever been in a television shop, back when they still had shops, you could find two screens next to each other showing the same television channel but with radically different colours, when you compare them side-by-side, but if you watch just one of the screens - it doesn't matter which - you get used to the colours of that screen and everything looks fine.