On my recent trip to the Mekong Delta, I would get on deck before sunrise... total darkness
Hoping to get a sunrise (didn't happen - too cloudy) and shoot the night fisherman (who use nets)
I blundered into shooting blind
Aiming at an indistinguishably black blob, I would half press the shutter and wait until the AF locked onto the subject then press
The camera found what I couldn't see and the auto ISO displayed a brightened frame on the lcd... too cool...