The Coen brothers have spent their careers adroitly tweaking Hollywood genre conventions and repackaging them in new forms.

Watch “Fargo,” “Inside Llewyn Davis,” “Blood Simple” or any of the other movies they’ve made over the course of an illustrious stint in the business and it becomes instantly clear that they are as steeped in cinematic knowledge as any of their counterparts.

One would not typically associate the term “love letter” with the Oscar-winning brothers, whose movies tend to skew more toward expressing cynical perspectives on the meaninglessness of it all.

And yet here we are with “Hail, Caesar!,” their latest film, which plays as a valentine toward the only subject to which the brothers might be so inclined: classical Hollywood cinema.

It’s about the bumbling star of a midcentury biblical epic (George Clooney), who is kidnapped straight off the studio lot by a mysterious group, and the efforts of a studio “fixer” (Josh Brolin) to secure him.

“The premise, or the situation, is something we thought about many years ago, and talked to Clooney about — the idea that he’s a movie star of that era who gets kidnapped off the set of a movie,” Ethan Coen says.

“Hail, Caesar!” is the fourth Coens collaboration with Clooney, who is about as close as we have to a classic Hollywood movie star these days, and who has previously starred in a series of Coens pictures known as the “idiot trilogy”: “O Brother Where Art Thou?,” “Intolerable Cruelty” and “Burn After Reading.”

“You have to have a certain lack of vanity to play that and let it hang out, which George does,” Joel Coen adds. “And he’s very funny. He’s a natural comedian. That’s something you either have it, or you don’t.”

The real star of the show is old Hollywood itself, and the brothers take special pleasure in re-enacting a host of staples: from the aforementioned biblical epic to a synchronized swimming sequence that recalls Esther Williams (starring Scarlett Johansson), a B Western starring a singing cowboy (Alden Ehrenreich) and a tap number involving sailors (including one played by Channing Tatum) that might have come directly out of “On the Town.”

“Esther Williams made something like 17 movies over many, many years, decades,” Joel Coen says. “During that time, they developed these skills and technology for accomplishing these fabulous production numbers and making these images in the water. Nobody has done that for the intervening years, the decades, since the last Busby Berkeley-Esther Williams movies were made. All of that is lost. ... So it was a strange exercise in reverse engineering what they had done, using both the old technology and modern technology.”

The brothers will happily expound on those sorts of production details, but ask them if they ever spend much time thinking about their beloved stature in the world of movies that they clearly love so much, and there’s relatively less to offer:

“No,” Ethan Coen says.

So don’t expect them at a Lebowski Fest anytime soon.

“There was an interesting moment once when we were in a movie theater together in San Francisco,” Joel Coen says. “It was a big multiplex. We went down this escalator, there might have been 20 screens in this place. There was a table set up, with a young woman maybe 18 years old behind the table, and this Lebowski paraphernalia on it. And Ethan stopped and he said, ‘What is this?’ And she said, ‘Oh, we show the movie every Friday night, and people come dressed up as the characters. And you should come, it’s fun, I think you might enjoy it, not having any idea who she was talking to. ... The culture, something slips loose. You’re surprised and a little horrified by where it’s gone, but you can’t control it.”