Promising filmmakers making their debut at the Sundance Film Festival have traditionally been confronted with a choice between two career paths: Continue cobbling together micro-budgets and remain cult icons, or make the leap to big-budget studio pictures.

But while directors, producers and distributors here argue about the changing definition of an independent film, a new path for filmmakers is emerging: They can become “mainstream independents.”

At this year’s Sundance fest, which ended Jan. 28, hot competition pic “The Brothers McMullen” was partially financed by Fox Searchlight Pictures. And the writer-director-star of the Long Island drama already has a deal for his next feature film with the same arthouse shingle.

Meanwhile, sophomore director Nick Gomez’s competition pic “New Jersey Drive” was financed by Gramercy Pictures – as was Wallace Wolodarsky’s “Cold Blooded.” Wolodarsky’s dark comedy also was partially financed by the producers responsible for New Line Cinema’s “Dumb and Dumber.”

Another sign of the merger between mainstream and arthouse: It’s getting harder to tell the difference between independent film producers and studio executives. MGM/UA production VP Jeff Kleeman is an active member of the Independent Feature Project and a devotee of arthouse product. Veteran independent producer Mike Nozick recently was tapped to run Robert Redford’s production company at Disney. The Samuel Goldwyn Co.’s John Manulis was an independent producer, whose pic “The Basketball Diaries” was acquired by New Line Cinema and premiered at this year’s Sundance.

With the studios and mini-majors increasingly throwing money at quirky filmmakers, this year’s class of Sundance directors is optimistic: They will have the opportunity to make personal films and not be consigned to starve in the East Village.

Will there be enough screens for all those little films? And will filmmakers unwittingly censor themselves as they try to make more accessible films?

“All these new resources are often perceived as negatives, as selling out, as commercialism,” says Sundance director of programming Geoffrey Gilmore. “But what we’re watching is a bit like what happened with alternative music a few years ago. Once record companies started embracing and releasing music that was fairly accessible and simply unknown to the general public, the public began embracing bands that were once considered too way-out by distributors.”

Those new resources manifested themselves at the festival in the form of cellular phones, supermodels and talent agency feuds for emerging directors.

After a churlish Hollywood producer refused to turn his cellular phone off during a screening, theater managers had to instruct moviegoers to refrain from making calls during screenings. Despite the warning, one exec took a call during an afternoon screening, shouting, “Hey, this is important. This is business!” as fellow filmgoers jeered and hooted.

One major indie distrib cursed a local theater manager when he was denied access to a sold-out screening. He concluded his soliloquy by asking for the man’s name and threatening to have him fired.

Supermodels Naomi Campbell and Linda Evangelista jetted in to generate some heat for the documentary “Unzipped.” Fine Line Features ended up acquiring Douglas Keeve’s look at designer Isaac Mizrahi. Music legend Brian Wilson lent some harmony to the fest when he arrived halfway through to support Don Was’ docu about him.

More than 25% of the films here had distribution going into the fest, and only a handful of dramatic filmmakers lacked a Hollywood agent at the fest’s outset – a marked change from years past.

Benjamin Ross (“The Young Poisoner’s Handbook”) and Ed Burns (“The Brothers McMullen”) were heavily courted by ten-percenters. Director’s reps from the Creative Artists Agency, the William Morris Agency and United Talent Agency crammed the first screening of Ross’ tale of a brilliant British schoolboy who practices better living through chemistry. A carload of agents from International Creative Management drove to Salt Lake City in order to catch one of three screenings for the film.

Sundance paterfamilias Robert Redford was unusually visible during the festival. He pressed the flesh in the Claim Jumper, a bar and grill that has been transformed into a between-screening hangout. Through it all, the movie icon reminded festgoers that Sundance was not about Hollywood but “about the filmmakers.”

He also offered several cautionary words to filmmakers on the renewed resources headed their way from Hollywood distributors and New York indies. “In my experience, if you scratch a lot of independent filmmakers, you’ll find someone who is dying to go to Hollywood.” But Redford stressed, “Hollywood can be lucrative, and it can also destroy a filmmaker.”

Sundance veterans argue that there are several explanations for the arrival of the mainstream independent. One is that the films are looking increasingly professional. Another is that indie filmmakers seem to be eschewing the avant garde.

“It’s becoming increasingly difficult to tell the difference between some of these first films and a studio film in terms of their quality,” points out John Sayles, the veteran independent director whose films include this year’s Sundance pic “The Secret of Roan Inish.” He adds, “Five years ago, you wouldn’t have seen an actor like Bruce Willis in a Sundance film. These first-time filmmakers are a lot slicker, a lot more technically adept than in years past.”

Mainstream independents also are tackling genre pix. Of the 18 films playing in competition, three were accessible comedies, two were thrillers, and two were vampire films.

“We have been seeing a lot less true experimental work in recent years,” says Gilmore. “Many of the same people who were experimental filmmakers in the ’60s and ’70s are probably going into other fields like multimedia.”

Veteran acquisition execs agree with Gilmore, saying that they too are seeing filmmakers who are coming from a more conventional background. The professors at the film schools, they feel, are less out of the avant-garde, image-oriented tradition and more from a conventional studio-system mind-set.

Still, it’s no picnic being an independent filmmaker. Indie films, including the mini-majors’ releases, only account for 6% of the total domestic box office. And arguably 3% of that box office was directly attributable to that paradigm of mainstream independent filmmaking, Quentin Tarantino’s “Pulp Fiction.”

Add to these woes the increasing competition among mainstream independent films for precious few screens.

“The number of films that are getting made is definitely increasing, but the number of slots for release are staying the same,” points out Sayles. “The result of the companies like Gramercy, Miramax and Fine Line building up their business is that there’s pressure on the art market. There are only so many weekends in the year and only so many screens.”

Competition filmmakers here bristle at the suggestion that the new mainstream independent cinema was a form of selling out. “This whole frou-frou about commerciality and budget levels is a lot of bullshit,” says James Mangold, who directed “Heavy.”

“There was nothing harder than getting this movie made,” says Mangold. “I spent five years of my life doing it. There’s no bag of money in it; there’s no guns in it. Hollywood did make these kinds of films at one time. But ‘Hud,’ by Martin Ritt, would have to be an indie if it were made today.”

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