Polar Panoramas
Shallow depth of field occurs when your camera settings have a low f stop number such as f 2.8. the shallow depth of field blurs the out of focus areas of the image.
Expansive depth of field occurs on the larger f stop numbers from f12-f22 this depth of field gets everything in focus even the background.
as you progress through the f stop numbers the lower the number the less in focus and the higher the number the ore that is in focus.