"Charles Gatewood is a photographer and anthropologist who specializes in "subcultures." On the evidence of "Dances Sacred and Profane," Mark and Dan Jury's documentary about Mr. Gatewood, he is drawn particularly to Mardi Gras revels, gatherings of nudists and sex clubs. Bare breasts, elaborately tattooed bodies and bizarre behavior are featured in his work, and in the movie. Addressing those who may find his subject matter "revolting and disgusting," Mr. Gatewood asserts that it "tells us som...