Luna said he also wants to use the Chavez story as a vehicle to illustrate the Mexican-American experience. Few Mexicans know who Chavez was, Luna said (and many Americans to this day think he was Mexican). Nor do Mexicans completely appreciate the way Mexican Americans live, with an eye on their past, a constant struggle to belong to their present and a desire to achieve equal standing among other American citizens.

“I hope the film brings out the complexity and challenges the audience on how much they really know the other side,” said Luna, 32, whose son was born in L.A. and is, thus, a Mexican American.

Cruz hopes that Canana’s reputation for quality, niche movies like “Sin Nombre” and “Miss Bala” will win over skeptics. (Luna and Cruz’s third partner in Canana Films, actor Gael Garcia Bernal, makes a cameo in the movie.)

Many of the actors seem in awe of the project. Pena grew up in Chicago, the son of Mexican farmers who had immigrated there. He said he knew the name Cesar Chavez but didn’t really know what the activist achieved in terms of raising the voice of the voiceless. Pena said his father nearly wept when the actor told him he was playing Chavez.

“Now I understand why he got so emotional,” Pena said between takes, looking kind of Leave-it-to-Beaverish in a checkered shirt and slightly bouffant wig (his hair, he said, is not long enough to re-create Chavez’s ’60s-style waves).

Ferrera, born in the United States to Honduran parents, was raised in California and said she always knew who Chavez was and admired him. While Pena could prepare for his role by studying historical footage of Chavez, Ferrera has had to portray a wife who stayed largely behind the scenes during the heyday of the workers’ movement. Helen Chavez, now 85, has met with Ferrera to discuss the history.

Helen “saw her husband’s role and really pushed it” while raising eight children, Ferrera said. “I was daunted. How do we convey the importance of that partnership and her still and quiet strength?”

Gabriel Mann, on summer hiatus from his turn as Nolan Ross on the TV series Revenge, is playing the scion of an orchard-owning family. He sees current-day relevance in the Chavez story. “In these days of union-busting in the States, this shows what happens when there are no protections,” he said. “It’s more timely than ever.”

Actor John Malkovich joined Chavez initially as a producer through his production company, Mr. Mudd. Eventually, Luna recruited him into the role of an abusive grape-grower. He was persuaded to take an on-screen role by his admiration of Luna’s work and a sense that the story was important. “To me, it’s also about simple human fairness,” Malkovich said.

Scores of extras were needed to play field hands and fruit company employees, and Hermosillo’s relative ethnic diversity was a boon for the filmmakers. Multinational companies like Ford Motor Co. have a long history in the area, so there was a pool of Anglo-looking performers to draw from; for Filipino fieldworkers, the filmmakers went to the city’s 67 Chinese restaurants and found 16 actors.

Ultimately, Luna said, he wants the film to be about something more than one man.

“We want to make sure that we pay tribute to those who fought for the community,” Luna said. “The way (Chavez) approached the struggle could be applied anywhere in the world.”