Quote:
Originally Posted by cellaris
If you compare colour with a tablet it loses out (4096 vs. millions) but if you compare it with a monochrome reader it wins out (4096 vs. 0). If you compare the unilluminated screen with a monochrome reader it loses because it is darker, but if you compare it with a tablet it wins because the tablet cannot be used without illumination.
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Colour eink can't be used without illumination in normal indoor light.
It's not actually 4096 colours or 16.7 Million (more for HDR screens). That's the total of the hues (colours), saturations and levels/brightnesses. The eink has black, white and approximately 14 grey levels. The LCD has between 256 and over 1000 distinct polarisations, those are translated to brightness changes by using one or two polarising layers. Both, apart from QLED based LCD panels, use coloured filters, either stripes or a 2 x 2 pattern of R G & B. (some LCD panels use R, G, B, Y and clear dots).
No-one bothers to make mono LCD HiRes graphic panels now, they are all coloured.
So ANY colour eink (not Gallery as it's not regular eink) is lower resolution than the best mono panel at that size, either 1/3:1 for Triton or 1/2:1/2 for Kaleido (X:Y). The result is so poor in contrast and brightness, because it's front lit and the filter reflects that light. Kaleido 3 uses the most washed out pastel red, green and blue dots to make the screen brighter at the expense of having really very poor saturation. Doesn't solve the filter reflecting a bit.
So likely 4096 is a little optimistic in total hues, shades and levels. Around 4000. Because there are only 14 levels between white and black the range of brightnesses for the same hue is limited. The hue will shift on all tertiary colours as the saturation or brightness is reduced. So colour rendition is very much worse than 4096 suggests.
As the monochrome is twice the resolution of colour eink the image can be dithered in a 2 x 2 cell (actually a more complex arrangement is used.
Without dithering it's less than 4096 vs 16, not 0. With dithering it's close to 64 shades, or 256 shades at slight loss of resolution. Laser and inkjet do this and only have on/off dots, though dot size can be varied.
Mono toned images will look better on mono eink than colour eink and won't need the front light in most situations. Text will look better on 300 dpi mono eink than colour unless the mono is an old Kindle Basic (167) or worse, a DX/DXG (only 150 dpi).
All decent mono eink are 300 dpi. The larger than 10.3" panels are lower dpi, which is one reason why I never bought a Sony DPT.
The only thing colour eink does better than mono eink is comics. The large enough ones for PDFs are too poor for the old scanned books and magazines without processing. The larger ones also have even worse resolution.
Now if E ink Corp. produces Kaleido 3 using 12" to 14" panels with mono 600 dpi (or at least 500 dpi) then that might be interesting. They'd still need a front light and 14″ is challenging to front-light evenly.