Sorry to revive this dead thread But I had to share this with you, guys.
Yesterday there was a powercut when I was at work in the underground (no windows), I just had my watch with me.
Naturally, the first thing I tried to get an improvised flashlight was turning on the backlight of my watch. But that was of no use - even at the highest brightness and with white background, the intensity is just not good enough…
The way to go is quite different! Consider this as a life-hack In these situations, you just take the watch off your wrist and activate the optical HR measurement. The optical HR sensor LEDs are much brighter than any “backlight flashlight”! Their flashing is slightly annoying, but better than nothing in such situations…