In a statement introducing Shelby Lee Adams’s “Salt & Truth” exhibition (on view through January 7), the artist claims it has become difficult to find “authentic, salt-of-the-earth people” to photograph. Adams’s words are those of a man who, for nearly forty years, has been photographing mountain dwellers in the eastern Kentucky Appalachians (not far from where he grew up), focusing always on the lifers rather than on the newcomers, many of whom are affiliated with corporate strip mining. But if change is apparent in this part of the country, Adams’s portraits stubbornly suspend it. Recent forays