John Marin the "undisputed father of American modernism" is in the limelight and many of his never-before-seen, privately-held works have figured into a new film. Independent film-makers Michael Maglaras and Terri Templeton have already produced two films about another great modernist painter, Marsden Hartley. Their latest project, "John Marin: Let the Paint be Paint!," premieres this weekend at the Portland Museum of Art in Maine, and then will travel...