In a season of exploding CGI spectacles, it’s pleasant to encounter a film that has the best special effects of all—a well-wrought script, great acting, understated direction and a production that conveys the needed period feel without showiness. Aaron Schneider’s “Get Low” is old-fashioned in the best sense, a picture for adults in an age largely devoted to cinematic childishness. Set in the 1930s, it resembles one of those Mark Twain adaptations that PBS used to make for “American Playhouse,” but though that might not be the highest of recommendations, it’s hardly a slur.

Robert Duvall does another brilliant variation of his patented cantankerous coot as Felix Bush, a reclusive man in Depression-era Tennessee who’s lived alone in his isolated cabin in the woods for some forty years, building up a reputation for eccentricity and meanness among the tale-spinning locals. He chases away the kids who come to spy on the legendary bogeyman, and is content with the company of his mule Gracie (his little cemetery is for his string of dogs).

One day the town minister (Gerald McRaney) drops by to let him know an old friend has died, and it gets Felix thinking. He ambles into town to ask the minister to arrange his own funeral—but with a unique feature: he wants it to be in the form of a big bash while he’s still alive, so that people can come to tell any stories they have about him while he’s around to hear them. The minister refuses, so he takes his money to Frank Quinn, the sad-faced director of the local funeral home, an expatriate from Chicago who complains that locals are dying fast enough to keep his parlor solvent. He leaps at the chance to stage such an event, bringing along his earnest aide Buddy Robinson (Lucas Black, absolutely unrecognizable from his juvenile roles of yore) in the project.

It’s one of the picture’s joys that Quinn is played by Bill Murray, who’s become a national treasure in supporting roles in films like “Rushmore,” “Zombieland” and this one. His dour countenance and impishly deadpan delivery are delightful in themselves, but when he and Duvall get together, juxtaposing the older man’s gruff orneriness against his knowing whimsy, it’s like watching two masters juggling in unison. Duvall also clearly relishes his scenes with the luminous Sissy Spacek as Mattie, a widowed old flame of his who’s recently returned from St. Louis, and grumpy Bill Cobbs, as an Illinois minister to whose chapel Bush travels in an effort to persuade the old man to come and preside at the festivities.

Those two relationships are in fact the key to what Felix has in mind with his plan—the expiation of an old sin he’s felt so guilty about that it led him to remove himself from society for four decades. And since he wants as large an audience as possible, to Murray’s delight Bush announces a lottery in which a small contribution will buy people a chance to inherit his spread after he dies.

This concluding turn of “Get Low” is actually a bit of a disappointment. For one thing, it’s at odds with what Felix initially described as what he wanted—an event at which others would talk about him (something that might have had a darkly humorous tone). But more important, it takes the picture into territory that could easily wallow in sentiment. Fortunately, Duvall delivers his confession with such dignity that the ending doesn’t turn maudlin. And there’s a certain rightness that a narrative of this sort should close with a “coming home” moment, because though Felix had never left the locality, he had abandoned contact with it.

The carnival-like finish also provides an opportunity for cinematographer David Boyd to show off his elegant russet-colored images on a broader scale that he can in most of the earlier scenes, and for costumer Julie Weiss to clothe a lot more folk in her thirties fashions. Production designer Geoffrey Kirkland, art director Korey Michael Washington and set decorator Frank Galline also deserve recognition, as does Jan A. Kaczmarek for the evocative score.

It will undoubtedly be common for commentators to compare Felix Bush with Boo Radley, the hermit Duvall played in his first feature appearance back in 1962. The two really aren’t alike except in the most obvious way, but like “To Kill a Mockingbird,” “Get Low” reminds us of the danger of judging people by appearances and the need to understand things from their perspective. Those aren’t exactly revolutionary sentiments, but they’re worth hearing again, especially when delivered as skillfully as they are here.