Lillian and Harold Michelson in L.A. in 1947

Even the most avid film buffs may never have heard the names Lillian and Harold Michelson. But they are considered Hollywood royalty to many of the most acclaimed filmmakers.

Alfred Hitchcock, Steven Spielberg, Francis Ford Coppola and Mel Brooks are among those who revered Lillian for her research skills that brought authenticity to motion pictures and Harold’s storyboard skills that conceptualized camera angles and scenes to be built, manipulated and shot.

Individually and together, the couple had a hand in the success of some of the greatest movies of the 20th century, including The Ten Commandments, Fiddler on the Roof, The Graduate, The Birds, Who’s Afraid Of Virginia Woolf? and Rosemary’s Baby.

“Harold and Lillian enhanced the quality of movies,” says producer Stuart Cornfeld. “They were the secret weapons that nobody talked about but everyone was trying to get.”

“Harold’s innate sense of cinema was incredible,” adds director Daniel Raim. “The way he could bring a scene to life, both verbally and on paper ….”

Raim decided it was time to bring the couple to the attention of the public — and does so powerfully with his documentary Harold and Lillian: A Hollywood Love Story. “Love” is the key word — the deeply engaging and moving film emphasizes their decades-long romance and family as well as celebrating these talents that have helped shape the films that are beloved to so many.

Lillian Michelson, 89, and retired, becomes the focal point of the film, being shown Aug. 11-13 at the Detroit Film Theatre. This presentation has special meaning for Raim: Detroit was the birthplace of his dad, writer Martin Raim, and his aunt, concert pianist Cynthia Raim.

“I like that the movie shows my [late] husband’s talent and publicizes what people do without getting credit,” explains Lillian, who has been speaking at screening sessions near her California apartment.

“It’s so [surprising] that the questions and answers have turned me into Ann Landers. The questions asked by people standing in line to shake my hand are about their families because the movie shows me overcoming obstacles in my life. I try to answer each one, and some of them are so sad.”

Lillian, referring to the late newspaper columnist who helped find solutions for troubled readers, openly talks about being an orphan, raising an autistic son and looking after her husband experiencing a severe injury and late-life illness. Through it all, even through her own health issues, she retained her adventurous, ebullient personality while inspiring optimism in others.

“I’m aiming for my 100th birthday; why not?” she tells people while encouraging them to forge ahead.

Raim got to know about the couple as a student at the American Film Institute (AFI), where Harold taught a class. He wanted to have their presence in the film as well as anecdotes from the famous people employing them, including Brooks, Coppola and Danny DeVito, a producer of this documentary.

“In the 1990s, I had two career-spanning interviews with Harold that I filmed and kept in my archives,” says Raim, born in Israel and now living in California. “The challenge of keeping him present in the film involved incorporating his poems and letters to Lillian.

“Harold was an interview subject in my first documentary. It was about Robert Boyle, an AFI professor who was Alfred Hitchcock’s production designer for five films, including The Birds, which Harold worked on.

“In 1999, Harold, Lillian, Robert and I took a trip to the coastal town where they made The Birds seven years earlier. It was the start of a friendship that lasted, and I see Lillian about once a month, more often when we’re doing presentations.”

Although Lillian speaks about professional and personal experiences, there are plenty of home movies, photos and letters (some sizzling) to bring the commentary to life.

“I told Daniel to use the home movies so they make sense chronologically, and he made this masterpiece,” she says. “I expected something very modest, but he really got into it. The documentary seems to have touched people all over the world. “

Lillian, born Jewish, and Harold, raised with a strong emphasis on Judaism, have valued the ethics of their religion.

“We had a rabbi marry us in a Sunday school because my husband had been given a very traditional Jewish education and had a bar mitzvah,” she says. “My husband knew how to do right. He was a decent and kind man. My religion is to be kind and good and do no harm.”

A learning experience not in the film confirmed Lillian’s outlook. She recalls a temperamental art director throwing her research materials at her and around the room. Although she wanted to respond in a way similar to his actions, she held back. He left and shortly returned to apologize and explain his behavior resulted from just hearing he had terminal leukemia.

“That experience taught me to be as kind as possible because you have no idea what other people are going through,” she says.

More representative of the attitudes of executives was the decision to use images of Lillian and Harold in the Shrek movies, where they were cast — and honored — as the film’s animated queen and king.

Lillian’s decades of research materials are being stored by the Art Directors Guild. Although she has had inquiries about the possibility of having them donated, Lillian is looking for a buyer so that she will have funds to leave to her three sons.

The work Lillian did with books and periodicals is now handled with internet searches. Lillian, for her personal interests, uses an iPad.

“I use an iPad because I never learned to type,” she says. “I use it to keep in touch with my friends, see movies and learn what Rotten Tomatoes is doing. I just touch and see, but I read books the old-fashioned way. “

Although Lillian was nervous about doing presentations, she gradually overcame that.

“When Dan was asking me questions, I forgot the little microphone on my chest and the camera in the corner,” she says. “He made it a pleasurable experience, and I felt I was just talking to a friend.”

Harold and Lillian: A Hollywood Love Story will be shown at the following times by the Detroit Film Theatre in the Detroit Institute of Arts: 7 p.m. Friday, Aug. 11; 4 and 7 p.m. Saturday, Aug 12; and 4:30 p.m. Sunday, Aug. 13. $5-$9.50. (313) 833-7900; Turner Classic Films tentatively will show the documentary at 8 p.m. Wednesday, Sept. 13. All the film that landed on the cutting-room floor was made into vignettes, Lillian’s Life Lessons, that will be shown on the DVD slated for release in October and on Facebook at that time.