WHEN ROBERT WASHINGTON sings like "the King," people shut up.

On a recent Saturday evening, the darkly handsome Elvis impersonator from Auburn, Maine, swaggers onto the makeshift stage of Inman Square’s Portuguese-American Club and the 150-plus people seated in the faux-wood-paneled room stop talking. Bowls of mashed potatoes are quickly set down. Camera shutters snap. Bodies lean in for a better view.

No one seems more mesmerized than three folks seated at the front table. Westborough native Kevin Bond, a fellow Elvis imitator with chunky mutton chops, stops chomping on his gum. Bond’s manager Carolee Burbank — bedecked with dangling Elvis earrings, a blouse patterned with yellow-and-brown Elvis portraits, an Elvis wristwatch (synchronized to Memphis time, natch), and Elvis’s lightning-bolt insignia tattooed above her right breast — is like a schoolgirl ogling her current crush: her eyes don’t leave Washington, she snaps pictures of him with her disposable camera, and when he sings the line "My chest is a-heaving" from "Burning Love," she thumps along on her breastplate. Across the table is Washington’s own manager, Alice Dickey, a 74-year-old from South Portland, Maine — the very town where, coincidentally, Colonel Parker was setting up camp in the Sheraton Tara hotel in advance of Elvis’s scheduled performance at the Cumberland County Civic Center on the day the King himself died. When Washington warbles Elvis’s slow numbers, Dickey gets glassy-eyed. "He makes me cry," she sighs later. "It doesn’t make any difference how many times he sings them, the ballads make me cry."

Such reactions are the subject of The Faithful, a documentary currently in post-production, about the devotees of Elvis Presley, the pope, and Princess Diana. Produced by the Somerville-based nonprofit Fish in the Hand Productions, The Faithful needs more money. So nearly everyone in this room has donated something — time, cash, energy — to help producer/director/writer Annie Berman and co-producer Sara Theriault, two 26-year-old filmmakers, finish their movie. But although tonight is an Elvis-themed fundraiser called "A Night with the King" — replete with a dripping 500-pound Elvis ice sculpture, a small booth selling messy fried peanut-butter-and-banana sandwiches, and a fluorescent-pink drink menu of concoctions with names like "Blue Hawaiian" and "Hard Headed Woman" — The Faithful will be less about Elvis, the pope, and Princess Di and more about people like Washington, Bond, and Burbank.

"It’s about the fans, the media, and culture," explains Theriault. "Elvis, a rock star, has become this kind of religious figure. The pope, a religious figure, has almost become a rock star. And somehow Diana has almost become a saint." And the ways in which worshipping celebrity, royalty, and religion overlap are exactly what The Faithful explores.

ANNIE BERMAN expected to see the pope’s face in the Vatican gift shop, maybe on rosary beads or sterling-silver medals. But the pontiff’s portrait on yellow-and-pink lollipops? His Holiness, arms outstretched, sold in snow globes? The Vicar of Christ’s visage on serving plates, spoons, and ashtrays? "I was always interested in how those objects are valuable because pictures of the pope are on them," says Berman. "And the pictures are so reproduced, so grainy, that they aren’t even necessarily nice pictures. But it’s the pope, so they’re very valuable."

Berman, a Florida native and Brandeis graduate, first saw the pope’s product line in 1999 while visiting a friend in Rome. At Brandeis, she’d been president of the photography club (the group’s vice-president, Marika Kaye, would later become The Faithful’s still photographer), and her visual avocation made Berman wonder how many copies could be made of a picture of the pope before the image lost its value; when did a copy of a copy cease to represent its subject? Berman, then 22, considered snapping pictures of these objects with a still camera and then later using a Polaroid transfer machine to replicate them, but her camera jammed. Still, the idea remained with her.

"I really wasn’t planning on making a film," Berman says, sitting at the 1369 Coffee House in Inman Square. "I just started reading and thinking about it." Then she started thinking about American figures who had similar effects on their loyal disciples. "Elvis just seemed like a logical next step."

So Berman spent a year researching both the pope and Presley. She wasn’t looking to compare the two idols, exactly — the head of the Catholic Church can’t really be equated with a dead rock-and-roll singer with a taste for pills — but to evaluate the ways their most worshipful admirers honor them. Both inspire thousands to undertake annual pilgrimages in their names. Both are objects of mass-produced iconography sold by entire gift shops devoted exclusively to them. Both have given rise to organizations that control the dissemination of their likenesses. And both have been stripped of their human qualities — by the faithful.

"I just go back to the idea that for someone to be an icon, we’re all responsible," says Berman. "And these people are our icons — anyone can think of their pictures immediately in their minds."

The more Berman read, the more she became convinced that her idea would be best explored through film. "Many books had been written with many of these ideas, but this is such a visual idea that it seems like you’re missing something when you read about it," she explains. In June 2000, Berman established Fish in the Hand Productions to anchor her cinematic project; a few months later, Berman, Kaye, and co-producer Matt Mankins went to Graceland for the 23rd anniversary of Elvis’s death, thinking footage of the celebration would constitute the Elvis segment of the film. The trio didn’t plan much; they mostly conferred with people they encountered randomly. "Looking at the footage later, the tapes became sort of an audition," recalls Berman. "Who do you want to know more about? What else would you want to know or see?"

Princess Diana didn’t become part of the idea until Sara Theriault came onboard in the fall of 2001. A classmate of Berman’s at Brandeis, Theriault had been working in television as an associate producer for Pinball Productions, a Boston-based company making documentaries for stations like Animal Planet and the Discovery Channel. After producing programs for the History Channel — Rum Running, Moonshining, and Bootlegging and Who Was the Real Boston Strangler? — the 26-year-old Californian had practical experience securing locations, music, and picture rights, so Berman asked her to join the project.

Theriault also brought another significant idea to The Faithful: character development. "The original idea was not character-driven — it was more about the visual elements," explains Berman. "But to really understand the subject, I think you have to identify with these people."