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You're right. People seem to have this misconception that the light from reflective displays like eInk is somehow different from that of emissive displays like
by fpgaminer 6y ago
You're right. People seem to have this misconception that the light from reflective displays like eInk is somehow different from that of emissive displays like LCD or OLED. Light is light. An LCD with _perfect_ calibration to the local lighting conditions would look indistinguishable from an eInk display, and thus we would expect it to have the same eye-strain reducing properties.
Put a different way: when light falls on an eInk "pixel" it gets absorbed and then re-emitted, modulo intensity. That's how we see the vast majority of surfaces in the world: they absorb light and then re-emit it, possibly changing its intensity and color (frequency). Technologies like OLED directly emit light; not reacting significantly to the ambient light that falls on them. But if one we able to measure the light falling on each individual pixel of an OLED, one could adjust each pixel to mimic the behavior of a physical object. It could "simulate" eInk, so to speak. If the mimicry is close enough, then there's no fundamental difference between the two. They'd both be emitting the same frequency and intensity of light.
In fact I recall a post, mostly likely here on HN: Someone took a high quality Apple display and rigged it with an array of ambient light sensors, put it in a decorative art frame and hung it on the wall. With some software and calibration they were able to get it to look convincingly like a real piece of art, fooling many of their guests.
eInk has been around for decades now and has remained an obscure niche. It's possible we'll see a renaissance for it, with the patents hopefully expiring? But there's no reason we shouldn't also be pursuing better ambient light calibration for our existing displays.
P.S. It's not accurate to say that eInk is a "reflective" display, as it does not primarily reflect light. Otherwise it would look like a mirror. But saying "emissive" versus "reflective" is common parlance for differentiating technologies like eInk from technologies like LCDs and OLEDs. Nitpicking the terminology is not particularly helpful though.
- ThrowawayR2 6y ago> "An LCD with _perfect_ calibration to the local lighting conditions would look indistinguishable from an eInk display" Too bad nobody actually makes one. There's no way to buy a hypothetical, so e-ink it is.
- Dylan16807 6y agoPerfect isn't the goal, it's just a word used to make the proof more obvious. The relevant question is whether you can buy an LCD that calibrates well enough, and the answer is not "obviously no".
- mypalmike 6y ago> misconception that the light from reflective displays like eInk is somehow different from that of emissive displays like LCD or OLED. Light is light. There is one specific difference between the light from LED screens vs e-ink : polarization. LED displays work by adjusting the polarity of the backlighting and then passing it through a polarizing filter. An e-ink display image is unpolarized light. It's not clear whether the polarity of LED has the potential to cause eye strain or other negative effects, but it is certainly a quantifiable difference.
- folmar 6y agoIf you don't care for small test group you can try to test it yourself with polarizing vs non-polarizing sunglasses.
- floatboth 6y ago> an obscure niche Are e-readers really obscure? Seems like a pretty big market.
- anotheryou 6y ago> In fact I recall a post I also saw something but couldn't find it again :) Is "reflective" always orderly? I mean, can there be a 100% matte reflection?
- orbital-decay 6y agoYeah, it seems that there's a lot of questionable (to put it mildly) claims and anecdotes surrounding e-paper regarding the long-term health effects - reflective vs emissive, blue light, polarization, contrast, you name it. I also use an e-ink reader sometimes because it looks so much better under direct sunlight, and because it's a single purpose physical device. But I'd love to see some more substantial work backing the eye and neurological disorders claims, from actual researchers in the field, with n greater than 1. Otherwise, that's how you get a snake oil market for geeks.