In a city brimming with film festivals covering a wide variety of themes, the Investigative Film Festival is just the latest niche cinematic offering. Dubbed “Double Exposure” and featuring both screenings and a symposium, the three-day event will run Wednesday through Oct. 2 at the National Portrait Gallery. Founded by journalist Diana Jean Schemo and former AFI Docs festival director Sky Sitney, the IFF includes appearances by an impressive array of experts from both journalism, courtesy of Schemo, and cinema, courtesy of Sitney.

The opening night film is “Spotlight,” an intense docudrama about the Boston Globe reporters who uncovered a massive sex scandal within the Catholic Church in a 2002 series of Pulitzer Prize-winning articles. Directed by Thomas McCarthy and featuring a star-studded cast that includes Michael Keaton and Rachel McAdams, “Spotlight” (opening Nov. 6) already has received rave reviews at the Venice, Telluride and Toronto film festivals. Following the invitation-only screening, David Simon, the former Baltimore Sun reporter and creator of HBO’s “The Wire” and “Show Me a Hero,” will moderate a panel discussion featuring McCarthy and the journalists whose reporting inspired the film.

Additional screenings include the documentaries “Cartel Land” (Thursday at 6 p.m.) and “(T)error” (Oct. 2 at 8:30 p.m.).

Michael Keaton, Liev Schreiber, Mark Ruffalo, Rachel McAdams, John Slattery and Brian d’Arcy James play the staff of the Boston Globe in “Spotlight.” (KERRY HAYES/Open Road Films)

According to Schemo, “Spotlight” occupies a changing landscape in both film and journalism, one in which the lines between cinema and detailed reporting have blurred. In a phone interview, the former New York Times correspondent — who went on to create the investigative news organization 100Reporters — explained: “I came up with the idea a year and a half ago because we were looking at the state of investigative journalism and thinking, ‘So much of [it] is moving into the visual sphere, and most people don’t have an idea of what investigative journalists do.’

“It actually came as a bit of a shock to me that [this festival] didn’t already exist. So I proposed the idea to the Knight Foundation and they gave us a grant.”

The name “Double Exposure” refers to the festival’s dual purpose. In addition to film screenings, Sitney and Schemo programmed a two-day symposium to create a dialogue between journalists and filmmakers. “We’re interested in the range of conversation that wouldn’t be possible with a pure film program,” Sitney said. “We can explore topics that are not specific to a documentary issue.” To that end, the symposium Oct. 2 will include a discussion of the whistleblowing documentary “1971,” featuring director Johanna Hamilton, as well as an appearance by NSA whistleblower Edward Snowden, via Skype.

Although the symposium is a forum for the discussion of such wonky policy issues as censorship, Schemo and Sitney insist that the festival is for everyone. Except for the opening night screening, every event at the festival is open to the public. An all-access pass (available for $225) includes lunches, happy hours and symposium events. A film pass is available for $50. Tickets to individual screenings are $12.75-$15.

Sitney said she’s proud of the filmmakers and journalists she and Schemo have brought together for Double Exposure. Additional guests include Alex Gibney, director of “Steve Jobs: The Man in the Machine” and the Academy Award-winning “Taxi to the Dark Side,” and Kirby Dick, who directed the campus rape documentary “The Hunting Ground.”

“I see [Double Exposure] as a different model, a different mission, than the traditional film festival,” Sitney said. “The films are punctuating a way to explore the spirit of investigative journalism in cinema.”

At the same time, Sitney said she recognizes that, in this community, “the audience always has a presence.” It’s an important point, since savvy filmgoers increasingly rely on candid, innovative investigative journalism to help shape what they think about challenging issues.

According to Schemo, the three-day festival is only the beginning. “This is not a one-off at all,” she said. “We’re building relationships and laying the groundwork for something to grow, to become an annual feature of the D.C. cultural scene.”

For more information about the festival, including a complete list of films, events and speakers, go to www.investigativefilm .

Zilberman is a freelance writer.