When in a dark place(especially at night time) when the lockscreen is set with a "Dark pre-installed wallpaper" the Face unlock doesn't work even after increasing the brightness to maximum level whereas if a "Bright pre-installed wallpaper is set (with/without auto brightness) the Face unlock works perfectly. Samsung should work on their wallpapers in a more detailed way.
Amoled doesn't have backlight like lcd. even with full brightness black won't reflect light needed for camera to see your face. how you gonna defy physics?
