A “Panoramic Head” or Pano-head is an
extra item that you can attach to the tripod, and upon which the
camera is placed. It ensures that the camera moves around the lens
– for reasons that will be displayed in “Setting
Up and Taking Pictures”. A pano head ensures the best
possible results.
<< Click and drag
over the image to the left to rotate it.
The way it gives better results is that by mounting the camera
in portrait mode, you get a greater vertical field-of-view ("FOV")
in your finished panorama. In other words you will be able to
view more up and down.
In addition:
They allow for adjustment to locate the camera's nodal point.
They allow you to shoot in precise increments so that you have
the proper amount of overlap of images required for the stitching
software.
More information about Pano Heads can be found
here.