If you want a very subtle shadow, keep the intensity value low. Changes the placement of the shadow. You can also use the mouse to move the shadow in the image window. Like with the Angle, you can also use the mouse to move the shadow in the image window and reposition it. The value you set determines how blurry, or soft, the shadow will be.
Large values extend and soften the blur of the shadow.
Determines how dark or light you want the shadow to be. Use Intensity in conjunction with Blur to get the effect you desire. You can also create an Inner Shadow effect , which applies a drop shadow inside the text, creating a 3-D effect.