Here's how a filmmaker shot his critically-acclaimed movie using just an iPhone

Earlier this year at the Sundance Film Festival, audiences were taken by zany comedy "Tangerine," the latest film from "Greg the Bunny" co-creator Sean Baker.

Baker enjoys telling stories set in real settings, casting actors with little to no experience, and exploring stories you've likely never seen before on the big screen. That can range from a New York garment district wholesaler dealing with fatherhood ("Price of Broadway") to a porn actress befriending an elderly woman ("Starlet").

"Tangerine" continues that motif as Baker tells the story of a transgender prostitute named Sin-Dee (Kitana Kiki Rodriguez) who learns that her pimp is cheating on her and navigates through Los Angeles on Christmas Eve to confront him.

But what has grabbed people's attention beyond Baker's unconventional tale is his decision to shoot the film only using the iPhone 5S.

"I didn't see any other way the film could be done," Baker told Business Insider in the Manhattan office of the film's distribution company, Magnolia Pictures, last week.

With a micro budget of only around $120,000 to make the film, Baker knew he had used up all his favors doing his previous films, and that if he wanted to make "Tangerine" he had to be creative.

"The film that turned me onto [shooting on an iPhone] was Spike Lee's 'Red Hook Summer,'" Baker said, referring to Lee's low budget 2012 drama. "Remember the kid shooting on his iPad? There's something about every time it cuts to his iPad footage I got more interested. I thought, Why isn't anyone doing a whole film like this yet?"

Around the same time Baker realized that the iPhone 5S was coming out, and included an upgraded camera lens from its predecessors.

Baker realized he could pull off shooting the movie with the phone (he used three total, but never at the same time).

Through camera tests with his co-cinematographer Radium Cheung, Baker liked the high quality of the picture the 5S provided. But he was completely sold on shooting with the phone after coming across a new anamorphic lens adapter for smartphones created by Moondog Labs and the app, FiLMiC Pro. 

With the lens adapter and the app, which made it possible for the phone to shoot at the level a pricey DSLR camera provides, Baker felt the phone would be "elevated to a cinematic level." (The FiLMiC Pro app costs $7.99 and the Moondog lens adapters range from $160-$175.)

And his financiers, who included Mark and Jay Duplass (creators of HBO's "Togetherness"), agreed after Baker showed them his test footage.

What Baker didn't realize until principal photographer on "Tangerine" began in the February of 2013 was the level of sophisticated shots they could pull off with the phone. Baker used his talents as a former bike messenger in Manhattan to weave closely around his characters as they said their lines. Biking with one hand on the handle bar and another holding a smart-phone designed Steadicam called a "Smoothee" ($149), the movie has these slick, eye-catching passing shots of Sin-Dee as she walks furiously throughout L.A.

But perhaps the most dazzling of the cinematography in the film are the "crane" shots.

Throughout the film a handful of scenes begin high above buildings and then smoothly travel down to the faces of the characters. On traditional movie sets giant crane rigs that cost in the thousands of dollars are used to pull this off. Baker was able to do the same shots cheaper and in a more practical way.

"We purchased a large painter's pole and we would rig the phone to the end of it and do these up and down movements," Baker explains has he stands and imitates the movements, almost like he's painting the walls off the Magnolia meeting room with a long paint roller. "We would do like 10 shots, one after the other, and then look at all of them on the phone and decide if we had to do it again. It was basically like being back in your parent's yard, 12 years old, doing stuff with the VHS camera."

Baker admits if the film was done a few years later they probably would have used drones for some of those shots.

Though shooting with the phone was a success, Baker was weary about promoting how "Tangerine" was shot. When the film got into this year's Sundance Film Festival back in January, he did not allow any of the publicity material to state that it was shot with an iPhone.

"We didn't want people to have any preconceived notions about how it would look," he said. "I have to say, if I had a choice to see a movie between a film shot on 35mm and a film shot on an iPhone, I would pick the film shot on 35mm."

But following the premiere screening, Baker knew he had to reveal how they shot it. Overnight, he became the poster child of the future of low budget filmmaking.

"It's starting to get crazy," Baker admits. "I'm getting way too many Facebook messages and Twitter DMs from people asking how I made the movie. I just don't have the time to answer all of them. It's so easy - you get the phone, you get the app, you get the rig and you just do it."

Apple has even warmed to the film.

Baker said when they originally sent Apple the film treatment they got the typical response that the company didn't want to be involved. But after the Sundance premiere he began hearing from multiple departments in the company. Some praising what he did. Others, not so much.

"A few times they had been really nice to me, but a few times they rubbed me the wrong way," he said. "One time a department was like, "We're coming to your apartment and we're going to shoot the way you edit and shoot and we're going to spend two days with you.' I was like no, you're not."

But all is well, as Baker said Apple invited the film to take part in one of their Apple Store filmmaker chats recently, and they were all given new iPhones.

Baker is not planning to make another film on an iPhone, hoping that he will have a much larger budget to work with on his next one. But he believes audiences will be seeing more movies made on phones in the years to come.

"I went to Sundance thinking we would be one of many films shot on a phone," he said. "But a lot of people are starting to use it for features and shots. And a lot have been used for commercials already. It's about time."

"Tangerine" opens in theaters on Friday.

Watch the "Tangerine" trailer below, and see the amazing picture quality yourself.