[Retr0id]

Hm, thinking about this further, this would need dithering to work properly (which probably works fine, but the perceived quality difference would mean pixel density comparisons aren't apples-to-apples)

Presumably, you get to control hue and brightness per-pixel. But that only gives you access to a thin slice of the sRGB gamut (i.e. the parts of HSL where saturation is maxed out), but dithering can solve that. Coming up with ideal dithering algorithms could be non-trivial (e.g. maybe you'd want temporal stability).

[kurthr]

You really can't think about single wavelength tunable pixels as something except at the edge HSL.

I think about it from the CIE "triangle" where wavelength traces the outer edge, or even the Lab (Luminance a-green/red b-yellow/blue) color space since it's more uniform in perceivable SDR color difference (dE).

https://luminusdevices.zendesk.com/hc/article_attachments/44...

One key realization is that although 1 sub-pixel can't cover the gamut of sRGB (or Rec2020), but only 2 with wavelength and brightness control rather than 3 RGB. Realistically, this allows something like super-resolution because your blue (and red) visual resolution is much less than your green (eg 10-30pix/deg rather than ~60ppd). However, your eye's sensitivity off their XYZ peaks are less and perceived brightness would fall.

I guess what I'm saying is that a lot of the assumptions baked into displays have to be questioned and worked out for these kinds of pixels to get their full benefit.

[Retr0id]

Good point, the HSL edge includes magenta which is of course not a wavelength.

[cubefox]

The "line of purples": https://en.wikipedia.org/wiki/Line_of_purples

[o11c]

Dithering is at worst equivalent to subpixels, which we already use.

If you take the "no subpixels" claim out of the article, this technology still seems useful for higher DPI and easier manufacture.

[Retr0id]

Sure, but PPI/DPI headline figures are usually counted per-pixel, not per-subpixel, so the raw density numbers aren't directly comparable (and I'm not really sure what a fair "adjustment factor" would be)

[mark-r]

"Fair" has nothing to do with it, the adjustment factor will be whatever the marketing folks think they can get away with.

[jessriedel]

> only gives you access to a thin slice of the sRGB gamut (i.e. the parts of HSL where saturation is maxed out)

Note that even if we restrict our attention to the max-saturation curve, these pixels can't produce shades of purple/magneta (unless, as you say, they use temporal dithering or some other trick).

[juancn]

You could use several pixels as sub-pixels or if the color shift time is fast enough, temporal dithering.

Even if these could produce just three wavelengths, if you can pulse them fast enough and accurately, the effect would be that color reproduction is accurate (on average over a short time period)

[refulgentis]

I'm not sure why saturation couldn't be controlled.

I probably missed something in the article, though I do see ex. desaturated yellow in the photographs so I'm not sure this is accurate.

If you can't control saturation, I'm not sure dithering won't help, I don't see how you'd approximate a less saturated color from a more saturated color.

HSL is extremely misleading, it's a crude approximation for 1970s computing constraints. An analogy I've used previously is think of there being a "pure" pigment, where saturation is at peak, mixing in dark/light (changing the lightness) changes the purity of the pigment, causing it to lose saturation.

[mark-r]

Any desaturated colors I saw were also very bright, so I blame it on overexposure of the camera. Probably looked totally different in person.

Unsaturated colors aren't a problem, you just need to mix a bit of the opposite color. Unsaturated purples will be a challenge because you need to mix 3 wavelengths rather than just 2.

[Retr0id]

Saturation can't be controlled on a per-pixel basis because, per the article, they're tuned to a specific wavelength at any given time.

You're right though, there appear to be yellows on display. Maybe they're doing temporal dithering.

Edit: Oh wait, yellow doesn't need dithering in any case. Yellow can be represented as a single wavelength. Magenta on the other hand, would (and there does seem to be a lack of magenta on display)

[cubefox]

> Saturation can't be controlled on a per-pixel basis because, per the article, they're tuned to a specific wavelength at any given time.

Where does the article say this? I couldn't find it.

[refulgentis]

Honestly might just be the limits of photography, there's so much contrast between the ~97 L* brightness of pure yellow and black that the sensor might not be able to capture the "actual" range.

I've been called a color scientist in marketing, but sadly never grokked the wavelength view of color. It sounds off to me, that's a *huge* limitation to not mention. But then again, if they had something a year ago, its unlikely ex. Apple folds its microLED division they've been investing in for a decade. Either A) it sucks or B) it doesn't scale in manufacturing or C) no ones noticed yet. (A) seems likely given their central claim is (B) is, at the least, much improved.