I have had good results putting my flashlight beam right on both grizzlies and blackies. I've had a grizzly stalk me hiking but keep his distance with my headlamp on before dawn. Now any certain bear could react differently, but like with my airhorn I prefer empirical data over armchair speculation.
Every large omnivore or carnivore has the capacity to kill us. I admit that blackies, lions, and wolves don't get my hackles up as much as a grizzly but its obviously important to give them all respect. Remember that on any hike wheter we worry about other humans or apex predators far and away the greatest danger of our hike is driving to the trailhead.