“The basic condition of the voyeuristic scenario is distance, an essential separation between seer and seen. Despite this distance, which is by definition unbridgeable, despite the unrequitable nature of the desire that drives it, the voyeur’s gaze is a privileged one.”
Great book I highly recommend called Train Your Gaze: A Practical and Theoretical Introduction to Portrait Photography by Roswell Angier. The quote above is from TYG. Almost by anyone’s definition it is not a book on portrait photography. It is really an analysis of contemporary art photography as well as some of the classic but nevertheless quite daring, in their time, 20th century photographers.
The chapter on voyeurism begins with a quote by Walker Evans, certainly an idol of mine and countless other photographers.
“Stare. It is the way to educate your eye, and more. Stare, pry, listen, eavesdrop. Die knowing something. You are not here long.”