WATERVILLE — The 17th annual Maine International Film Festival is set to begin Friday, with more than a half-dozen movies playing on opening night, including the 12-years-in-the-making “Boyhood.”

The film — critically acclaimed for being shot over 12 years with the cast growing with the characters — is the type of programming director Ken Eisen says he tries to bring to the film festival each year.

“The criteria for new films is merely something we think is excellent, it’s as simple as that,” Eisen said Thursday morning. “The second component is it has to be something we think our audience will appreciate. It has to be both.”

A diverse portfolio of films and other shows is instrumental in providing the festival its international variety, Eisen said.

“We don’t have quotas for the films, we don’t try to get a certain amount of anything,” he said. “Even with Maine films, we’re certainly devoted to promoting them, but if there aren’t any Maine films worthy, we won’t show them.”

Several Maine short films will be shown at MIFF this year, as will live musical performances at the Opera House.

“There’s a very strong connection between the Opera House and film, historically,” said Dick Dyer, director of marketing and development for the Opera House, which holds 800 guests. “Given that we host an eclectic array of performing arts, film is very important part of that, and here we have a larger space to accommodate those larger viewings, while also staying intimate. It allows for much more versatility.”

The Opera House will host the opening ceremony Friday night, where Eisen, Maine Film Center Director Shannon Haines, Colby College President David Green and Waterville Mayor Karen Heck will all speak. It will also be the site of Sunday’s Mid-Life Achievement Award ceremony for Glenn Close and viewing site for her film “Albert Nobbs.”

“Ticket sales have been very strong, not surprisingly the strongest sales have been for the ‘Albert Nobbs’ showing and the opening ceremony with ‘Boyhood,’ ” Haines said. “Opening night is always very busy, it’s very bustling at the Opera House and people are excited for the festival to kick off.”

Haines said Thursday that volunteers are finishing decorating the two theaters — the Opera House and Railroad Square Cinema, which has three screens — as well as testing the box office system so it works properly. The first weekend is a whirlwind for the organizers, Haines said.

“Honestly, we don’t feel any relief until Monday, the first weekend is quite busy and it’s packed in,” she said. “There are at least four screenings a day on four different screens.”

More than 200 tickets and 48 passes had been sold as of 2 p.m. Thursday. Passes for one admission to all public events costs $200. A partial pass is available for $85 and provides a punch card good for two admissions, up to two per show, for festival screenings and special events. Individual films and events range from $9 to $15.

Waterville resident Susan Reisert was one of about three dozen attendees to buy tickets or passes on Thursday at Railroad Square Cinema. Reisert, who has bought passes for the past seven years, said she’s looking forward to ‘Boyhood,’ as well as the Mid-Life Achievement ceremony.

“There are also a couple obscure movies I’ll want to see that normally don’t come around here,” she said.

In addition to the weekend marquee events, 21 filmmakers and actors will attend opening weekend. More than 60 filmmakers and actors are expected to attend the festival.

“We’re very excited, we have a huge number of visiting filmmakers and many are here this first weekend,” Eisen said, adding that was not the case when the festival started in 1998. “There were a lot less, I don’t think more than a half-dozen. The growth has been pretty much exponential.”

Friday night’s opening ceremony will be followed by an opening night party at 9:30 p.m. at Mainely Brews.

This story was updated at 2:50 p.m. Friday, July 11 to clarify information about partial festival passes.