"I used to cross that Chandler Highway bridge to and from work every morning, I started to think about who the artist was," Pinches told AAP.

"One day, I stuck a letter up on the bridge and the artist came back to me and we made a film."

The documentary Be You T. Fool is inspired by the painter, who taught herself the skill of portraiture by drawing people on the train in Melbourne.

"The film is about communicating her idea, it's about the beauty in everyone, it's our inner fool that makes us human," Pinches said.

One of the biggest challenges for the filmmaker was keeping the talent's identity anonymous.

"It was really hard to film her while keeping her identity secret but the limitation helped us a little bit, it made us frame it around the artwork," Pinches said.

Heading up the judging panel was Hollywood A-lister Eric Bana, who was back in Australia after wrapping up true crime podcast-turned-Netflix series Dirty John.

Bana told the crowds at Parramatta Park he was most looking forward to seeing the films shared in front of an audience for the first time, and their reaction would ultimately influence his decision.

"I'm looking forward to seeing the collective emotion here tonight, it doesn't necessarily have to be a barrel of laughs," he said on Saturday night.

"It doesn't get better than having your films played in front of an audience like this."

No stranger to adversity, Tropfest has weathered many storms over the years.

Resurrected in 2016 following its cancellation a year earlier because of funding mismanagement by the former contractors, this year it was nearly abandoned again after rain damaged the set-up.

Footage from the wild storm that lashed Parramatta Park showed the film screens being battered by wind and the stage being pummelled by torrential rain.

But the production crew toiled away overnight to find a fresh location for the screenings and build a new set.

Fellow Aussie actor Marta Dusseldorp, who joined Bana on the judging panel, acknowledged the hard task ahead of Tropfest finalists.

"To make a film in six, seven minutes is unbelievably hard," Ms Dusseldorp told AAP.

"What I'll be looking for tonight is a deftness of touch, a really good point of view, it can't just be a scene in a feature or a long short," she said.

Mystery Road actor Aaaron Pederson said he was looking for an X-factor in the film and the winner had it.

"This film had that magic spark," Mr Pederson told AAP.

"All the judges were in agreement."

Pinches won the top prize of $10,000 and a brand new Holden car worth $32,000. He will also spend a week in Los Angeles meeting agents and studio executives as part of his prize.

Earlier in the night, Pearl Beach local and second-time finalist Kat Alexander won Tropfest Junior for her feminist-inspired film REWIRE about a robotic teenage girl.

"It's definitely a feminist film and told through a feminist outlook," Ms Alexander told AAP.

"I think it's important to talk about because now it's got a lot of coverage and now I want to add what I have to say," she said.

The 15-year-old says she's been inspired by women in the industry, especially director Kathryn Bigelow.

Australian Associated Press