Lynne Sachs had already been working as a filmmaker for several years, finding her voice in making personal documentaries, when in 1991 she decided to make a movie about her dad.

“I was interested in the ways you could know a person, and to articulate that in film,” Sachs said in a recent interview. “I definitely didn’t know where it was going to go. Or that it would take almost 30 years making it.”

Sachs’ long journey toward understanding her father, former Park City developer Ira Sachs, will reach a major milestone on Friday, Jan. 24, when her movie, “Film About a Father Who,” has its world premiere as the opening-night film of the 26th annual Slamdance Film Festival in Park City.

Slamdance, showcasing independent movies made for under $1 million, runs Jan. 24-31 at Park City’s Treasure Mountain Inn, parallel to the larger Sundance Film Festival.

Peter Baxter, co-founder and president of Slamdance, said programmers chose Sachs’ movie because it “reveals how far bloodlines can stretch without losing connection altogether. While Lynne provokes us into choosing between love and hate, she assuredly explores the degree to which one human can know another.”

When Sachs started the movie, she said, “I was keen on looking at my dad and figuring out what made him tick, and how that had an impact on me on the rest of the family.”

(Abby Lord | Courtesy of Lynne Sachs) Lynne Sachs is the director of the documentary "Film About a Father Who," which will premiere Jan. 24, 2020, as the opening-night film of the 26th annual Slamdance Film Festival.

“If I’m engaging with my father through my art-making, and through my life as his daughter, [I thought] that there could be some kind of catharsis, and that I could explore it both artistically and intellectually, but also emotionally,” she said.

Early footage shows Ira Sachs at work as a real estate developer, splitting his time between Memphis, Tenn., and Park City. (One of his best-known properties in Park City was The Yarrow, the hotel now known as the DoubleTree by Hilton, at Kearns Boulevard and Park Avenue.)

Sachs started coming to Park City in the late ‘70s, but didn’t move there full-time until 1986 — when Lynne’s younger brother, Ira Sachs Jr., graduated from high school in Memphis.

“He was kind of ready to live in the mountains, ready to live somewhere where he could explore the land more and be a pioneer more,” Sachs said of her dad. “The West beckoned. ... He never wanted to go to Aspen or Vail. He wanted to go somewhere that was rougher, that was kind of finding itself.”

(Photo courtesy of Slamdance Film Festival) Ira Sachs Sr., the former Park City developer, is the subject of the documentary "Film About a Father Who," directed by his daughter, Lynne Sachs. It will be the opening-night film of the 2020 Slamdance Film Festival on Jan. 24, 2020.

Sachs and her Memphis-raised siblings would visit Park City, and she even recalls attending one of the early editions of the United States Film Festival (which is what Sundance was called before 1991).

Ira Jr. was inspired by the independent film festival atmosphere, and also became a filmmaker. Five of Ira Jr.’s movies have debuted at Sundance, and he won the Grand Jury Prize in 2005 for “Forty Shades of Blue,” which starred Rip Torn as an irascible music legend with a much-younger wife.

That movie was inspired by Ira Sr., who had divorced his first wife — Lynne and Ira Jr.’s mother, Diane — and married a younger woman, Diana. Ira Sr. had three children with each wife, and those siblings were the only ones Lynne Sachs knew about when she started making her documentary in 1991.

Later, she learned her dad had other girlfriends, two of whom had daughters, Beth and Julia, with Ira Sr. A ninth child, a daughter named Madison, was born later.

“How many families have discovered similar quote-unquote ’secrets’ to mine, but through science?” Lynne Sachs said. “In some ways, this story is unusual in that it doesn’t use DNA.”

In three decades of working on “Film About a Father Who,” the movie now “contains all of my whole emotional spectrum, which is a little bit scary,” Lynne Sachs said. When she showed the film to friends during editing, “they’d say, ‘You haven’t really reckoned with all your rage as a daughter and as a young woman.’ Other times, I needed to reckon with [the fact that] I have forgiven my dad. He was complicated and very untraditional, but also a loving and very attentive father,” she said.

Ira Sr., now 83 and living in Florida, has seen the movie twice, Lynne Sachs said. “He cried, and I’ve never seen him cry before,” she said, adding that her dad has developed some speech issues that make it difficult to communicate directly. “I think he likes it,” she said. “There’s an openness to it, and I think there’s a candor that he respects, from all of us.”

Sachs said she hopes people will see her father as a unique character, but not that different from most dads.

She said, “I want people who watch it to imagine, ‘Well, how might I explore my father? What would be the questions I would ask? Maybe there were things he kept from me, because maybe he was protecting me — or maybe he had a side he didn’t want me to know.’”

SLAMDANCE RETURNS
The 26th annual Slamdance Film Festival, presenting lower-budget independent movies with an edge, returns to Park City.
Where • Treasure Mountain Inn, 255 Main St., Park City.
When • Friday, Jan. 24, to Friday, Jan. 31.
Tickets • Available at the box office at Treasure Mountain Inn, or online at slamdance.com.
Schedule • At slamdance.com.