Sundance: Robert De Niro Screens HBO Doc on His Late Father, Bradley Cooper Attends

"Remembering the Artist Robert De Niro Sr." screened Sunday, followed by a Q&A with the filmmakers and Robert De Niro himself.

PARK CITY -- Robert De Niro the actor has never been particularly forthcoming about his personal life -- nor anything else, for that matter. The very private New York-based Oscar winner rarely gives interviews or shows up at events. But for the first time, he reveals a great deal of his youth and upbringing, his early family life, and his relationship with his father, the late figurative painter Robert De Niro Sr., in Remembering the Artist Robert De Niro Sr. It will make its television debut in June on HBO, and its Sundance debut was met with enthusiasm, curiosity -- and surprise.

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De Niro himself showed up for the Sundance filmmaker panel afterwards, along with his producing partner Jane Rosenthal (who produced the doc with HBO's Sheila Nevins), director Perri Peltz, and Megan Fox Kelly, De Niro's art consultant who appears in the film.

Robert De Niro Sr., we learn, was part of the post WWII set of New York painters -- Jackson Pollack, Lee Krasner, etc -- and he enjoyed initial success by being championed by Peggy Guggenheim at her New York gallery Art of This Century in the '50s. Actor De Niro appears in the film, reading from his father's very personal journals (which reveal he left De Niro's mother, also a painter, when he realized he was gay) and talking about watching his father paint as a child.

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Unlike the New York abstract expressionists, De Niro Sr. was really a figurative painter -- and while he enjoyed great success when he started out, eventually when the New York art world went crazy for pop art in the '60s, De Niro Sr.'s work went out of fashion -- and he refused to conform. He moved to Paris for a time, but was eventually brought back to New York by his son, who admitted he helped him financially in his later years.

"I did this for him," De Niro told the crowd at the Yarrow Theater after the screening. "I wanted my younger kids -- who were born after he died -- to know what their grandfather did. I even kept his painting studio intact so they could see it."

Rosenthal explained that she pushed De Niro -- who'd always talked about making a doc about his father's work -- two years ago, knowing that many of his father's contemporaries in the art world -- who are featured in the film -- wouldn't live much longer. "Originally," admitted director Peltz, "Bob wanted to make the film just for his family. But then we realized it tells the story not just of Robert De Niro's Sr.'s work -- which is amazing -- but the entire art world of the time."

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De Niro is upfront in the film about his father's depression because he was not recognized in his time, and his inability to conform to other styles and get along with many of the gallery owners. Not surprisingly, the younger De Niro owns many of his father's works and many of his mother's early works (she gave up painting early on to raise him).

Many of De Niro Sr.'s works are being exhibited at the Julie Nestor Gallery in Park City, and Megan Fox Kelly admitted that a major show of his work in New York is not far off.

Meanwhile, almost without being noticed, Bradley Cooper -- in a ski cap -- was spotted ducking out of the screening. Obviously, his relationship with De Niro -- mentor and mentee -- is the real thing as Cooper has not made any other Sundance appearances at parties or dinners, and no one knew he was in town.