Back in the day, the kibbutz was the emblem of Israel around the world. A sabra in uniform may have graced the cover of Life magazine, but she was illustrating the same core principle — that every Israeli was obliged to contribute to the state.

The communal cooperative concept attracted thousands of idealistic non-Jewish volunteers from Europe and elsewhere in the ’70s hungry to experience non-materialism, and thousands of American Jews (including this writer) eager to contribute a bit of manual labor to Israel’s agrarian collectives.

But not many people talk about kibbutzes anymore, as their population has dwindled, Israel has achieved first-world status, and their influence on the country’s politics and psyche has waned.

Ran Tal’s “Children of the Sun,” screening three times in the upcoming S.F. International Film Festival, is a fascinating inside portrait of the kibbutz. It’s a personal history rather than a social study, in that it is more interested in the individual experience of growing up in a kibbutz than in the institution’s role in Israel’s development.

Tal, who was born and lived until his early 20s on the kibbutz his grandparents co-founded, gives us the recollections of some two dozen older kibbutzniks, including his mother.

However, he dispenses with the familiar, formulaic talking-head style of documentary, weaving their interviews instead into an audio collage. One effect — since he doesn’t show us his subjects’ faces until the end credits — is to underscore the kibbutz ideal of sublimating the individual’s identity to the group. At the same time, the interviewees repeatedly reiterate what it was like having their needs continually disregarded in favor of group needs.

The images are almost entirely taken from home movies shot on the kibbutzes from the 1930s to the ’80s, augmented with the occasional bit of archival news footage. Sometimes the voices on the soundtrack react to a clip from their own lives — “There’s my sister. What a doll-face” — with a quality akin to the commentary track on a DVD.

At other times, Ran illustrates their recollections with a stream of “generic” footage of children playing or exercising. Since he gives the film the structure of an individual lifespan, beginning with infancy and continuing into adulthood, it’s as if we are watching an entire generation grow up before our eyes.

In the early days, the kibbutz system was both a grand socialist experiment founded on idealistic principles, and a system designed to produce a “new man,” a fit, outdoors type who was the antithesis of the shtetl Jew.

In practice, that meant that children were raised in a nursery from birth, and lived with the other children all the way through adolescence. They spent a couple of hours with their parents in the late afternoon, and that was it.

One interviewee recounts that as a newborn his name was put to a vote among the kibbutz members, with his father’s choice (to name him after his grandfather) narrowly edging out the one proposed by a member.

A benefit of the system was that assigning a few kibbutz members to take care of the children freed up all the other adults to work. Any aspects of the traditional parent-child relationship that the child would be deprived of were sentimental and contributed to traits that weren’t compatible with the “new man.”

As you might expect, many of the voices say they grew up perfectly happily and embraced or (depending on one’s perspective) were brainwashed with the group ethos. After all, as children themselves, they certainly weren’t aware of alternate approaches to childrearing.

Other interviewees, not unexpectedly, harbor some pain, regret and resentment. Those who saw the Israeli drama “Sweet Mud” when it opened the S.F. Jewish Film Festival last year will better appreciate its bitter point of view after seeing “Children of the Sun.”

Ran’s documentary, which won the prize for best documentary at the Jerusalem Film Festival, doesn’t have a narrative or dramatic story, per se, but generates some tension in the gap between the past and the present.

On one hand, it is so steeped in acute personal experience that it becomes an involving, emotional viewing experience. But the film also seems to emanate from far away, because it arrives at a time when the notion of utopian societies seems more than ever like science fiction.

We’ll have to wait for another film to probe the prospects of kibbutzes in the iPhone era. And yet another film to trace the movement’s contributions to the founding of Israel and its formative identity. For now, “Children of the Sun” is an outstanding compilation of a captivating oral history.

“Children of the Sun” screens 3:30 p.m. May 2, 9:30 p.m. May 6 and 1:30 p.m. May 8 at the Sundance Kabuki, S.F., in the S.F. International Film Festival. Tickets cost $10-$12.50 and are available in advance at (925) 866-9559 or www.sffs.org.