In film and video editing, a convention that a shot of a subject from one side should not be followed immediately by a shot of the same subject from the opposite side (a 180-degree shift). The traditional argument has been that most viewers would find this disorientating since it produces a mirroring effect that could threaten narrative comprehension. For instance, filming a moving vehicle in this way might be misread as an abrupt reversal of its direction of travel or even as a head-on crash with itself. However, there are many examples of celebrated film-makers who do break this rule and, arguably, modern audiences have grown more tolerant of such transgressions because of their knowledge of film editing practices. See also 180-degree rule.
http://www.mediacollege.com/video/editing/transition/reverse-cut.html Crossing the line
Subjects: Media Studies.