Currently, numerous paths lead to panoramic photography. Before the
advent of data processing and computer software, only three approaches
existed, and as we have seen in the Preface, they date to the very beginnings
of photography. The easiest approach always has been the classic letterbox
(or elongated) format of an isolated photo, which remains more or less rectangular.
Here, the field of view taken in is equal to the wide angle of the more conventional
format (from which the panorama is taken). Whether one trims the top or
bottom of the photo, the width remains the same.