okay, i know that photoshop is a very sophisticated program, with many advanced features and stuff, but for the LIFE of me, i cannot figure out how to get photoshop to recognize that i've got a pressure-sensitive tablet thing plugged in and that i want it to respond to the pressure on the tablet. i tried doodling with the brush settings, but all i could get was a jittery line when i press hard. and, is there such a thing as pencil mode? like, you know how with a pencil, the both the opacity and the thickness of the line depend on how much you're pressing into the paper? can photoshop do that?