I use a Kobo eBook reader and an iPhone X. My iPhone can go super dim, to the point that it's hard to see in a dark room. I use no special features. Also, Kob

I use a Kobo eBook reader and an iPhone X. My iPhone can go super dim, to the point that it's hard to see in a dark room. I use no special features. Also, Kobo's eBook readers can go very very dim, and can be comfortably read in a zero light room. The max brightness I use is 29%-31%, dependent on lighting. My reader has a fixed light, but newer ones also adjust light temperature automagically, and much more comfortable to read (got one as a present for my dad).