6 ms·

https://news.ycombinator.com/item?id=17724995 https://news.ycombinator.com/item?id=17724995 Was a good thread

by thomas 8y ago

fermienrico 8y ago
I don't see anything related to reflectivity vs. backlight illumination. Most of the discussion is around the wavelength of light (blue) and its effects.
- coder543 8y ago
  does light have any other intrinsic properties besides spectrum/wavelengths and intensity (EDIT: properties that vary based on the light source alone)? It doesn't matter if it came from a backlight or reflection, the electromagnetic waves are still electromagnetic waves. If the color spectrum is unpleasant, it's possible to use Night Shift or other features to shift the spectrum. If the intensity is unpleasant, just turn down the brightness.
  - romed 8y ago
    The problem is LCDs have much worse objective performance as the backlight diminishes. E-Ink has tragically bad contrast of 15:1, but it maintains that contrast ratio in low lighting conditions. LCD panels rely on high brightness for their contrast. At very low brightness, even the best LCD display has poor contrast. OLED displays have a different problem; they have so much noise at low brightness that the image falls apart. Still, I think a monochrome OLED display is what the person who wrote this article actually wants. It would have better performance in every respect to E-Ink, and it doesn't sound like their application requires E-Ink's low power.
    - coder543 8y ago
      I have used both LCD and OLED smartphone displays at incredibly low brightness in pitch black rooms for a long time, and I have to completely disagree. On the other hand, E-Ink is amazing in sunlight, where smartphone displays can't get sufficiently bright.
      - singularity2001 8y ago
        Which smartphone displays can you set to 'incredibly low brightness'? all iPhones and Androids I've used are like bright flashlights when the lights are switched off.
        coder543 8y ago
        It's all relative. I don't own a single flashlight that can be set dimmer (or anywhere close to as dim) as my iPhone XS Max is at minimum brightness on a white page. If the XS Max is showing mostly-dark content, the amount of light emitted is really tiny at minimum brightness because of that OLED display. On the various Android devices I've owned, I've used a useful app called Screen Filter that adds a translucent layer on top of all apps to dim the screen beyond the artificial manufacturer-imposed minimum brightness, which worked especially well on OLED Android phones, but also LCDs worked fine too.
        orbital-decay 8y ago
        Presumably, all or most Xiaomi phones. I've never used one for long, but the lowest backlight level in those I tested (Redmi Note 2, Mi A1, RN5) was comparable to the level 2 or 3 of the Kindle Paperwhite frontlight. (level 1 is a failsafe option since the Paperwhite has no physical buttons, it's not meant for reading, being too dark even for a pitch black room) That said, I don't think reading in poor lighting conditions is a good idea for your eyes, no matter the technology.
        Obi_Juan_Kenobi 8y ago
        You can use an app to reduce the brightness further. I've been using Twilight on Android, and it does indeed get much dimmer. You will certainly lose some image quality/performance, but it's very nice for viewing in a dark room.
  - jseliger 8y ago
    This is actually a reply to @Romed: OLED displays have a different problem; they have so much noise at low brightness that the image falls apart. Still, I think a monochrome OLED display is what the person who wrote this article actually wants. It would have better performance in every respect to E-Ink, and it doesn't sound like their application requires E-Ink's low power. My understanding too is that OLEDs can have "true black" pixels that emit no light at all. For "dark mode" style screens, this is a huge benefit, because the majority of the screen may simply be turned off. Conventional LCD screens still send current to each pixel, but the "black" is simply tuned to a dark frequency, rather than being altogether off.
    - romed 8y ago
      Yes, an unpowered LED emits no light. But an OLED that's barely on, for example at uniform 1% grey looks like crap because of the noise. People describe this as a "texture" or "banding". It's the consequence of trying to drive millions of individual semiconductor devices to the same emissive power. At higher brightness you can't notice the noise.
    - tinus_hn 8y ago
      Lcd screens are transparent and selectively block the light from a backlight. They can’t show full black because they can’t completely block the backlight.
  - pvg 8y ago
    does light have any other intrinsic properties besides spectrum/wavelengths and intensity? Sure, think of things like polarizing filters, lasers, etc.
    - coder543 8y ago
      Lasers are just a method of creating light of a single wavelength. The light itself from the laser is still defined by its wavelength and intensity. Polarization is just related to the orientation of the electromagnetic waves, and it is a property I didn't mention, you're correct. I don't think it really matters here, though. It's kind of like which direction you shine a light, except whether the waves are all oriented the same way or not. I would almost argue that it's an extrinsic property since uniform polarization is almost exclusively the realm of external things like filters, not the light source itself. Your "etc." is a little vague.
      - pvg 8y ago
        You were suggesting light doesn't have any other 'intrinsic properties' and that's not the case - phase (a laser is not just a monochromatic light source) and polarization come to mind. Whatever it is you're trying to argue, 'light is just wavelength and intensity' is not a sensible starting point.
        coder543 8y ago
        Is it not sensible, though? People are trying to argue that light from a backlight is inherently more dangerous than reflected light. The easiest way to dispel this notion is to establish that the light from a backlight is just light like any other, which it is. At most, it varies in spectrum and intensity. Polarization is affected by filters outside of the light source. The phase that's hitting your retina varies entirely based on irrelevant things like when the light source was turned on and how far away it is. Starting by pointing out that intensity and wavelength are the only intrinsic properties is a great starting place. You still haven't pointed out any additional properties that have any bearing on how your retina is affected. I was wrong the say that there were no other properties, since we can endlessly discuss the quantum nature of light or how it experiences no flow of time since it travels at the speed of light or all sorts of other properties... but none of these things change based on the light source. Light is light, except for the intensity and wavelength. Unless we're willing to consider things which could affect reflected light just as much as they could affect emitted light, since they're the same thing. Light.
  - fermienrico 8y ago
    Yes, I know what electromagnetic waves are. I found your response very off-putting. The question is whether the intensity is discussed in the link. My point was that the discussion is more to do with the frequency of light than with intensity.
djsumdog 8y ago
Yea I remember that discussion. I'm not sure if I'm entirely convinced, but there are so many studies in progress looking at this that I decided to try running Redshift on my desktop again. I will say, it does seem to make it easier to fall asleep at night.

https://news.ycombinator.com/item?id=17724995 https://news.ycombinator.com/item?id=17724995 Was a good thread

by thomas 8y ago

https://news.ycombinator.com/item?id=17724995 https://news.ycombinator.com/item?id=17724995 Was a good thread

I don't see anything related to reflectivity vs. backlight illumination. Most of the discussion is around the wavelength of light (blue) and its effects.

coder543 8y ago
does light have any other intrinsic properties besides spectrum/wavelengths and intensity (EDIT: properties that vary based on the light source alone)? It doesn't matter if it came from a backlight or reflection, the electromagnetic waves are still electromagnetic waves. If the color spectrum is unpleasant, it's possible to use Night Shift or other features to shift the spectrum. If the intensity is unpleasant, just turn down the brightness.
- romed 8y ago
  The problem is LCDs have much worse objective performance as the backlight diminishes. E-Ink has tragically bad contrast of 15:1, but it maintains that contrast ratio in low lighting conditions. LCD panels rely on high brightness for their contrast. At very low brightness, even the best LCD display has poor contrast. OLED displays have a different problem; they have so much noise at low brightness that the image falls apart. Still, I think a monochrome OLED display is what the person who wrote this article actually wants. It would have better performance in every respect to E-Ink, and it doesn't sound like their application requires E-Ink's low power.
  - coder543 8y ago
    I have used both LCD and OLED smartphone displays at incredibly low brightness in pitch black rooms for a long time, and I have to completely disagree. On the other hand, E-Ink is amazing in sunlight, where smartphone displays can't get sufficiently bright.
    - singularity2001 8y ago
      Which smartphone displays can you set to 'incredibly low brightness'? all iPhones and Androids I've used are like bright flashlights when the lights are switched off.
      - coder543 8y ago
        It's all relative. I don't own a single flashlight that can be set dimmer (or anywhere close to as dim) as my iPhone XS Max is at minimum brightness on a white page. If the XS Max is showing mostly-dark content, the amount of light emitted is really tiny at minimum brightness because of that OLED display. On the various Android devices I've owned, I've used a useful app called Screen Filter that adds a translucent layer on top of all apps to dim the screen beyond the artificial manufacturer-imposed minimum brightness, which worked especially well on OLED Android phones, but also LCDs worked fine too.
      - orbital-decay 8y ago
        Presumably, all or most Xiaomi phones. I've never used one for long, but the lowest backlight level in those I tested (Redmi Note 2, Mi A1, RN5) was comparable to the level 2 or 3 of the Kindle Paperwhite frontlight. (level 1 is a failsafe option since the Paperwhite has no physical buttons, it's not meant for reading, being too dark even for a pitch black room) That said, I don't think reading in poor lighting conditions is a good idea for your eyes, no matter the technology.
      - Obi_Juan_Kenobi 8y ago
        You can use an app to reduce the brightness further. I've been using Twilight on Android, and it does indeed get much dimmer. You will certainly lose some image quality/performance, but it's very nice for viewing in a dark room.
- jseliger 8y ago
  This is actually a reply to @Romed: OLED displays have a different problem; they have so much noise at low brightness that the image falls apart. Still, I think a monochrome OLED display is what the person who wrote this article actually wants. It would have better performance in every respect to E-Ink, and it doesn't sound like their application requires E-Ink's low power. My understanding too is that OLEDs can have "true black" pixels that emit no light at all. For "dark mode" style screens, this is a huge benefit, because the majority of the screen may simply be turned off. Conventional LCD screens still send current to each pixel, but the "black" is simply tuned to a dark frequency, rather than being altogether off.
  - romed 8y ago
    Yes, an unpowered LED emits no light. But an OLED that's barely on, for example at uniform 1% grey looks like crap because of the noise. People describe this as a "texture" or "banding". It's the consequence of trying to drive millions of individual semiconductor devices to the same emissive power. At higher brightness you can't notice the noise.
  - tinus_hn 8y ago
    Lcd screens are transparent and selectively block the light from a backlight. They can’t show full black because they can’t completely block the backlight.
- pvg 8y ago
  does light have any other intrinsic properties besides spectrum/wavelengths and intensity? Sure, think of things like polarizing filters, lasers, etc.
  - coder543 8y ago
    Lasers are just a method of creating light of a single wavelength. The light itself from the laser is still defined by its wavelength and intensity. Polarization is just related to the orientation of the electromagnetic waves, and it is a property I didn't mention, you're correct. I don't think it really matters here, though. It's kind of like which direction you shine a light, except whether the waves are all oriented the same way or not. I would almost argue that it's an extrinsic property since uniform polarization is almost exclusively the realm of external things like filters, not the light source itself. Your "etc." is a little vague.
    - pvg 8y ago
      You were suggesting light doesn't have any other 'intrinsic properties' and that's not the case - phase (a laser is not just a monochromatic light source) and polarization come to mind. Whatever it is you're trying to argue, 'light is just wavelength and intensity' is not a sensible starting point.
      - coder543 8y ago
        Is it not sensible, though? People are trying to argue that light from a backlight is inherently more dangerous than reflected light. The easiest way to dispel this notion is to establish that the light from a backlight is just light like any other, which it is. At most, it varies in spectrum and intensity. Polarization is affected by filters outside of the light source. The phase that's hitting your retina varies entirely based on irrelevant things like when the light source was turned on and how far away it is. Starting by pointing out that intensity and wavelength are the only intrinsic properties is a great starting place. You still haven't pointed out any additional properties that have any bearing on how your retina is affected. I was wrong the say that there were no other properties, since we can endlessly discuss the quantum nature of light or how it experiences no flow of time since it travels at the speed of light or all sorts of other properties... but none of these things change based on the light source. Light is light, except for the intensity and wavelength. Unless we're willing to consider things which could affect reflected light just as much as they could affect emitted light, since they're the same thing. Light.
- fermienrico 8y ago
  Yes, I know what electromagnetic waves are. I found your response very off-putting. The question is whether the intensity is discussed in the link. My point was that the discussion is more to do with the frequency of light than with intensity.

djsumdog 8y ago

Yea I remember that discussion. I'm not sure if I'm entirely convinced, but there are so many studies in progress looking at this that I decided to try running Redshift on my desktop again. I will say, it does seem to make it easier to fall asleep at night.