"There is a reason that Hollywood invented
the close-up (other than to suffer the vanity
of leading actors). Filling the frame is a powerful
and immediate device for directing someone's
attention to the main subject. The minute the
camera closes in on the gunslinger's belt,
you know there's going to be some shooting-
there's little doubt about what the director
wants you to notice.
Moving closer-either physically or optically-
isolates your subject and is like saying
to the viewer, "This is what I want to show you."
Jeff Wignall "The Joy of Digital Photography" page 105