Kershner, who taught screenwriting at USC in more recent years, died Saturday at his home in Los Angeles after a 3 1/2-year battle with lung cancer, his family said.
A former documentarian whose more than 40-year career included work in television, Kershner earned his first credit as a feature film director for the low-budget 1958 crime drama "Stakeout on Dope Street."
He went on to direct 14 other feature films, including "The Hoodlum Priest," "The Luck of Ginger Coffey," "A Fine Madness," "The Flim-Flam Man," "Loving," "Up the Sandbox," "The Return of a Man Called Horse," "Eyes of Laura Mars," the James Bond film "Never Say Never Again" and "RoboCop 2."
"He was a director of extraordinary versatility," Peter Rainer, film critic for the Christian Science Monitor, told The Times on Monday.
"If you look at the reach of his movies, from 'Empire Strikes Back' to 'Loving,' one of the most nuanced and powerful Hollywood films ever made about a marital breakup, I'd say he was probably the most successful versatile director in Hollywood," said Rainer. "He could do just about anything really well, from science fiction to cult thrillers to domestic dramas to westerns to romantic comedies."
Kershner considered it "a freak of fate" that he is best known for "The Empire Strikes Back," which many consider to be the best installment of the phenomenally popular "Star Wars" film series.
"When George approached me, at first I wouldn't agree," Kershner told the Commercial Appeal, a Memphis newspaper, in 1997. "I didn't want to follow a picture like 'Star Wars,' because what could I do that was different? But George said, 'I want to make a picture that is better than the first one. Because if the second one is not successful, that kills the whole series.'"
It took him nearly three years to make "The Empire Strikes Back," Kershner said.
"I really knocked myself out," he said. "I was able to go deeper into the characterization. I was doing the second act of a three-act play, or the second movement of a symphony. That's always the slower movement. I could not have a grand climax, I had to leave things ambiguous. My big climax came at the beginning of the film, with the battle in the snow, then I told the story of the people."
In a statement Monday, Lucas said: "The world has lost a great director and one of the most genuine people I've had the pleasure of knowing. Irvin Kershner was a true gentleman in every sense of the word."
Lucas, who attended Kershner's lectures at USC when he was a film student in the 1960s, said he "considered him a mentor."
After "Star Wars," Lucas said, "I knew one thing for sure: I didn't want to direct the second movie myself. I needed someone I could trust, someone I really admired and whose work had maturity and humor. That was Kersh all over. I didn't want 'Empire' to turn into just another sequel, another episode in a series of space adventures. I was trying to build something, and I knew Kersh was the guy to help me do it."
In 1970, film critic Pauline Kael described Kershner as a director "who has been on the verge of broad recognition for over a decade."
Twenty years later, Rainer, then a Times staff writer, wrote in The Times that Kershner was "criminally underrated" as a director.
Most of Kershner's movies, Rainer said Monday, "didn't just jump out at you; they were very subtle, understated, beautifully crafted."
Kershner, Rainer added, "had a great ability to showcase the powerhouse actors in roles that showed off their softer sides as, for example, Barbra Streisand in 'Up the Sandbox,' Robert Shaw in 'The Luck of Ginger Coffey' and Sean Connery in 'A Fine Madness.'"
After the war, he studied art and design at the Tyler School of Fine Arts at Temple University in Philadelphia, as well as studying with renowned artist Hans Hofmann. After moving to Los Angeles, Kershner studied photography at the Art Center College of Design and began studying film at USC, where he also taught photography.
Back in Los Angeles in the early 1950s, he directed, shot and edited the documentary portion of the award-winning syndicated TV series "Confidential File," hosted by newspaper columnist Paul Coates.
Kershner, whose early TV work included directing episodes of "The Rebel," "Ben Casey" and "Naked City," also directed the 1977 TV movie "Raid on Entebbe" and the pilot for the 1990s TV series "seaQuest DSV."