Quote:
Originally Posted by HarryT
Precisely my point. There is exactly zero difference between directly-emitted and reflected light as far as your eyes are concerned. It's all about light levels, not the path by which the light reaches your eyes.
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No, it is not just about the light levels.
The path matters to the polarization of the light.
LCd light is uniformly polarized while ereader scattered light is a random mixture of polarizations. Try looking at an LCD through polarized glasses.
Another thing that matters is that ereader front lights use unfiltered LEDs which is why the hue varies from unit to unit. Some yellowish, some faintly green or occasionally blue. LCD backlight, however, always runs through filters: red-green-blue.
white backgrounds on lcd always put out blue light which is what the software filters do: they mute the intensity of the blue pixels. Because about a third of thelight coming out of white sections is pure blue.
The actual amount of blue light will vary depending on design so you can't really use measurements from one iPad model to another much less other brands. And applying those measurements to an entirely different lighting system is just bad science.
The blue light effect is real but it is primarily a color display issue.