“We wrote the part with Richard in mind,” Max Cohn said, referring to the father in “Proof of Concept.”

Chloe, a young filmmaker, is tagging along with her father, Robert, and his brother Ed as they run errands on the Upper West Side. From the dry cleaner’s to the stationery store, from Zabar’s to Barney Greengrass, Chloe pursues the siblings, as pesky and insistent as a gnat. She wants something from them—specifically, ten thousand dollars. That way, she can fund her short film, a work that, she explains, would make for a “proof of concept,” which she’d then be able to expand into a feature. Robert, however, is confused. “It seems counterintuitive,” he says. “Why don’t you just put the ten grand toward the feature?” Ed, who fancies himself a bit of an expert on the movie industry, responds, sagely, “A short film is the foreplay you do before performing coitus in the film world!” (“I hate that analogy, Uncle Ed, but it’s not wrong,” Chloe admits.)

Chloe is played by Ellie Sachs, who also wrote and directed the gently humorous film, “Proof of Concept,” alongside her friend Max Cohn. “This movie was really born out of our befuddlement around the short-filmmaking process,” Sachs said. “As soon as we asked ourselves, ‘Has anyone ever made a short film about short filmmaking?,’ we wanted to be the first,” Cohn added. Sachs, who lives in Los Angeles, and Cohn, who lives in New York, got on the phone with me recently, and were joined on the call by Richard Kind, the beloved comic character actor, who plays Robert. Kind, who lives in New York but was spending the week in L.A. for work, had asked to delay the call by ten minutes so that he could finish up a golf game, and was patching in from the locker room. (“It’s boiling hot, and people are walking around buck naked!” he said.) Golf, it turns out, was also part of the casting process. “We wrote the part with Richard in mind,” Cohn said, “and then my friend Will [Janowitz, who ended up playing Uncle Ed] said, ‘My neighbor plays golf with him!’ and passed him the script.”

Both Sachs and Cohn grew up in the city—Sachs in SoHo and Cohn on the Upper West Side—and, when they were thinking of where to set “Proof of Concept,” Cohn saw his old stomping ground as the right choice. Sachs, who, for a past project, remade Woody Allen’s “Annie Hall,” starring senior citizens, agreed. “The Upper West Side is so filmic,” she said. The city, in general, seemed to her like a great backdrop for Chloe’s striving. “It’s the cheesiest thing to say, but New York is a character here,” she said, naming as inspiration other N.Y.C.-based movies like the Safdie brothers’ “Daddy Longlegs.” As for the film’s specific shooting locations, “we were only able to get them because of Richard,” Cohn told me. “We went into Barney Greengrass and Zabar’s and asked if we could shoot there for free, and they said, ‘Absolutely not.’ Then when we came back with Richard, they were, like, ‘Of course, how long do you need? An hour? Two hours?’ ”

“Proof of Concept,” meanwhile, has been fulfilling one of the chief aims of any short, by being accepted into a cluster of festivals, among them the Tribeca Film Festival and New/Next. But, when asked if they were planning to follow up on the movie’s own meta-premise and expand it into a feature, the two filmmakers said to “stay tuned.” They did know, however, that they’d love to work with Kind again. Kind scoffed good-naturedly. “For the feature, you’re going to get Paul Giamatti,” he said. Cohn quickly objected: “We will accept no Richard Kind substitutes!”