CLAYTON -- A crew is set up at a home in Clayton, filming interior and exterior scenes for the narrative short film, "Emily and Billy."

The Clayton site is one of several in the Bay Area where the entire film was shot and just wrapped up this week.

"It was one of the smoothest film sets I've been on," said producer Lyniel Dao. "After the writing, casting and preproduction, it's in the can. We have the footage."

"Emily and Billy" is about a real phenomenon called prosopagnosia, or "face blindness." People with face blindness are unable to recognize facial features and are thus unable to identify others.

The Clayton scenes involved circus performers, including a juggler, trapeze artist and ringmaster. Other scenes were filmed in Richmond, Pinole and Santa Rosa.

"You work so hard that once you start filming it's a rush," said Dao. "I love being on set in the creative part of it."

The character of Emily in the film, played by 7-year-old Emily Kessel of San Ramon, suffers from face blindness. The opening scene filmed in El Cerrito, with about 20 extras ages 7 to 9, deals with Emily's difficulties in class and in making friends because of her condition.

Emily will meet Billy, played by 9-year-old Everett Meckler of San Jose, and the two will become friends.

The lead actors and extras were chosen from around the Bay Area via websites, SFcasting.com and Reeldirectory.com,

"Emily has face blindness, and she's lonely and quiet," explained director and screenwriter Ari Sigal. "Billy, who has a blank face, is the only person she can recognize, so they're a good fit as friends."

Meckler's facial features will be obscured using a combination of makeup and postproduction special effects, said production manager Marlenee Emigh, who grew up in Concord, and who was on site for the one-day Clayton filming at the home of a friend.

Sigal, who grew up in Albany, studied acting at New York University before returning to the Bay Area to attend the Berkeley Digital Film Institute, graduating about a year ago.

Dao, another film institute graduate, raised $3,000 for the production in about 10 days via Kickstarter.com, a website that displays artists' ideas and invites contributions from interested benefactors.

The two are trying to raise additional funding using Kickstarter and applying for grants.

Face blindness was the subject of a "60 Minutes" segment in May, titled "Face Blindness: When Everyone is a Stranger."

Primate expert Jane Goodall, psychiatrist Oliver Sacks and artist Chuck Close are among the more famous people who admit to having it, Sigal said.

"Sacks talks about a time he thought he was talking to someone else until he realized he was speaking to his own image in a mirror," Sigal said. "I find it an interesting disorder, and I wanted to write something about it."

Sigal and Dao plan to enter the movie in film festivals, including the Palm Springs Short Film Festival, the San Francisco Film Festival and the Albany Film Fest.