I have the habit of reading a lot in pitch black darkness (before falling asleep), and after a few minutes even the lowest brightness of my tablet (iPad 1) or phone (Samsung Galaxy Pocket) starts to be too much.

I wonder if backlit e-ink devices have a lower minimum brightness, or if it is similar to that of tablets and phones.

I ask mostly because it would be impossible to test this realistically in a shop.


I don't know every single ereader on the market, but my Kobo Glo has a lighting that when set at its lowest level don't hurt my eyes at all.

Furthermore its screen is not backlit. Eink screens are different from LCDs, they are an entirely different technology and are not lighted from behind. Usually their lighting is provided by LEDs positioned on the side of the screen, so that the screen receive their light perpendicularly and not directly emits it. In fact, there are also ereaders without any lighting at all, it is a feature separated from the screen itself.

This way the light is pointing towards the screen and not directly into your eyes, resulting in a comfortable reading.

  • I understand this and this is the main reason why I am seeking eInk: I believe it absorbs a lot of the more harmful spectra of light, reflecting a more natural radiation. But my question regards overall luminance, because I would like the light to be very, very dim, so as not to bother my sleeping-by wife, for example. After some time in the dark, even the faintest tablet or phone lighting setting (or night-mode if available) becomes a floodlight! Feb 27 '15 at 18:50
  • Well, nobody can answer to this, it is too subjective. I can say that it doesn't hurt my eyes and that from my point of view it doesn't emit a light that could disturb someone else. But I am not you, I can't say with certainty that something acceptable for me would be equally acceptable for you. Anyway, I don't think that someone that is sleeping, or having closed eyes, could be annoyed at all by the faint light of an ereader. There are some studies that seems to point out that using any light emitting device could disturb your sleep afterwards,but that's another matter.
    – Sekhemty
    Feb 27 '15 at 18:57
  • I see. I supposed this would not be an easy question to answer. I think it would be more of comparing the eReaders while used as flashlights. If you take two flashlights and point them to a wall, you can immediately say which one is brighter (supposing they have a similar beam geometry). That would be more or less the test I would like to perform, and perhaps someone here might have more than one device to compare. Anyway, thanks for your consideration! Feb 27 '15 at 19:02
  • Many e-ink devices do not even have backlights, and those that have go much lower than LCD/TFT screens.
    – CL.
    Mar 2 '15 at 10:12

I experienced the same annoyance when using my Smartphone at night time in a very dark room. Fortunately I discovered the Android app Screen Filter lately which enables additional screen dimming.

The app works totally fine on my Galaxy S4, but as the display is used outside of its intended range of brightness, the color reproducibility is far from perfect. For the rather simple purpose of displaying text this should still be sufficient.

So this could be a feasible for your already owned devices. (I don't know if there exists such an app for apple devices)

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