Film production expert Eve Light Honthaner says in The Complete Film Production Handbook (Focal Press, 2001 p. 211.):

"Publicity photos have traditionally not been copyrighted. Since they are disseminated to the public, they are generally considered public domain, and therefore clearance by the studio that produced them is not necessary."

Film industry author Gerald Mast, in Film Study and the Copyright Law (1989) p. 87, writes:

"According to the old copyright act, such production stills were not automatically copyrighted as part of the film and required separate copyrights as photographic stills. The new copyright act similarly excludes the production still from automatic copyright but gives the film's copyright owner a five-year period in which to copyright the stills. Most studios have never bothered to copyright these stills because they were happy to see them pass into the public domain, to be used by as many people in as many publications as possible."

Kristin Thompson, committee chairperson of the for Cinema and Media Studies writes in the conclusion of a 1993 conference with cinema scholars and editors, that they "expressed the opinion that it is not necessary for authors to request permission to reproduce frame enlargements. . . [and] some trade presses that publish educational and scholarly film books also take the position that permission is not necessary for reproducing frame enlargements and publicity photographs."[2]