Films about caped avengers, Hobbits and young wizards are often packaged as franchises.
Sequels are less expected, though, for documentaries about working-class patrons of Minimal and Conceptual art.
But "Herb & Dorothy 50x50" is just that: Megumi Sasaki's follow-up to her 2009 film about Herbert and Dorothy Vogel -- him a postal clerk, her a school librarian in New York City -- who accumulated an enormous and trailblazing art collection.
Though the works are worth millions of dollars, the couple donated their collection to the National Gallery of Art in Washington in 1992.
This collection became so large that much of it ended up in storage, away from public view.
So, in 2008, after an agreement with the museum, the couple said they would donate 50 works to a museum or gallery in each state.
This film documents that project, visiting 11 such exhibitions. (Herbert Vogel died in 2012, before the documentary was finished.)
Sasaki said she was inspired to make this second film after seeing the first of the 50 exhibitions, at the Indianapolis Museum of Art.
"I was shocked at how little I had known up to that point about the Vogels' collection and their ability to discern and select artwork," she says in the publicity notes.
"Every new place I visited had me pondering, 'What is art really?'"
That is a big question. Yet it goes unasked, much less answered, by this film's rapid-fire shots of the works on display.
(The exception is a playful animation of one series of colorful paintings.)
It's difficult to dislike a documentary with such noble, generous subjects, but the film is unfocused and repetitious, not sure whether it is a road trip, a story of a couple or an exploration of small art institutions.
Interesting ideas can be gleaned, higgledy-piggledy, but without much cooperation from the director.