Once shooting in a windowless quonset building, a really good shot said that if all he had was a spec of light or so dark one could barely see a deer that he would never miss. FUN!! We blocked out every source of light, then stuck a lighted site pin in a match box and punched a tiny hole and taped it to the target stack, 20 yards and then turned out the lights. When the lights were out, I moved the box, "Wait, Let me stick another piece of tape to it doesn't fall down." When we were all safely behind the shooter, he shot five arrows, then I tried one shot, I cheated, I moved my bow hand around until I could sort of tell where it was, then straight drew and released. With the first total dark shots, he never even came with in two feet of it, I was a foot high and left. Then someone pushed the door and let in a bit of light, he was in the process of taking one more shot, that shot clipped the edge of the match box. The difference between low light and absolutely no light.