In many American cities it can seem like a weekly arts battle: The small art house movie theater trying to steal attention — and audiences — away from the weekend’s big title with the big star. It’s a cinematic war that has led to the rise of an unlikely art house army, a rebellious band of filmmakers, studios, theater owners, and festivals, all committed to defying Hollywood and expecting something more from cinema than opening weekend box office receipts.

For the last 50 years, one of the more recognizable symbols of this army — the flag if you will — has been the black-and-white, two-faced logo of Janus Films. As Martin Scorsese has said, the logo “meant that you were going to see something special, something new, something completely different from anything you’d ever seen before.”

On college campuses across the country, before the untimely deaths of so many film societies, students would file in every week to Janus 101 — their weekly dose of foreign film study. To read through the films, and names, imported by Janus during the 1960s, ’70s, and in years since, makes the company’s mark on America’s cinematic community undeniable — names like Ozu, Herzog, Eisenstein, Truffaut, Renoir, Bergman, De Sica, Carne, Fellini, Kurosawa … the list goes on and on. They are the names that today are found on the syllabus of any freshman film class; together they constitute the foundation of the art form itself.

Recently Janus Films, founded in 1956 by Bryant Haliday and Cyrus Harvey, owners of Cambridge’s Brattle Theater and the 55th Street Playhouse in Manhattan, announced a plan to continue that cinematic education. Beginning Saturday night, in conjunction with the New York Film Festival, and running through October 26, Janus will celebrate its 50th anniversary by screening new 35 mm prints of some 29 titles from its catalogue — a remarkable festival within a festival that, for some, might well eclipse the NYFF program showing down the street.

Most impressive about the Janus retrospective is not the depth, but the breadth of the titles, several of which might be unknown to even the most devout cineastes.The series starts Saturday where most film fans would expect, with the moody love triangle of Truffaut’s “Jules and Jim,” before moving on to the technical perfection of Renoir’s “Rules of the Game,” and the profound morality play of Bergman’s “Seventh Seal.”

In addition to these conventional classics, Janus has programmed a number of unexpected and underappreciated masterpieces. On Sunday, Roman Polanski’s very first film, “Knife in the Water,” captures the director’s uncanny ability to sustain a sense of dread — a style he would later perfect in “Rosemary’s Baby” and “Chinatown.” On Tuesday, the series highlights an Bergman film that even Bergman fans might not be entirely familiar with: “Monika,” an essential building block of the French New Wave.

Then there are some real surprises, like Kon Ichikawa’s societal drama “The Makioka Sisters,” Carl Theodor Dreyer’s “Day of Wrath” — which is partly about a 17th-century witch hunt and partly about a flawed woman, a flawed church, and tragic sense of justice — and Victor Sjostrom’s 1921 silent, metaphyiscal thriller about the nature of death, “The Phantom Carriage,” complete with a live accompaniment.

It is an unprecedented program — a collection Janus plans to take around the country before delivering it to stores as part of a 50-movie DVD box set. A must-see and a must-buy, it seems the perfect way to celebrate this movie company, this essential cinematic institution, still fighting the good fight.