A scene from “The B-Side: Elsa Dorfman’s Portrait Photography,” the latest documentary by acclaimed filmmaker Errol Morris (“The Fog of War,” “The Thin Blue Line”).

A scene from “The B-Side: Elsa Dorfman’s Portrait Photography,” the latest documentary by acclaimed filmmaker Errol Morris (“The Fog of War,” “The Thin Blue Line”).

A scene from “The B-Side: Elsa Dorfman’s Portrait Photography,” the latest documentary by acclaimed filmmaker Errol Morris (“The Fog of War,” “The Thin Blue Line”).