How do you avoid charges of sensationalism if you set out to make a movie about the world’s first sex-change operation?

The simple answer is that you aim high. You set out to deliver a serious story and a quality product free of lurid tabloid exploitation.

It also helps to attach some big-name talent to the enterprise. People like Oscar-winning actresses Nicole Kidman and Gwyneth Paltrow and director Lasse Hallstrom.

Hallstrom says that, if all goes well, shooting on The Danish Girl will begin in May in Europe, and he couldn’t be more enthusiastic about a project that’s already generating controversy, and which will test the talents of all concerned. But the 63-year-old filmmaker isn’t worried.

“It’s the story of the first man who ever did a sex change: a Danish painter. Nicole is playing the man who turns into a woman, so that will be fun.”

Still, the project has experienced some bumps along the way. Kidman committed early on to the role of Einar Wegener, the Danish-born artist who died in 1931 as Lili Elbe after a series of male-to-female sex reassignment surgeries. But Charlize Theron, originally announced for the role of Wegener’s wife, Gerda, who was also an artist, withdrew from the production and was replaced by Paltrow. The film also lost its original director, Swedish filmmaker Tomas Alfredson, who was replaced by fellow countryman Hallstrom.

The film is an adaptation of a novel by David Ebershoff – a novel that recreated one of the most unusual love stories of the 20th century. It will return to a pivotal moment in the relationship – the moment more than a hundred years ago, when both artists were working in their studio, and Gerda Wegener unexpectedly found herself without her female model. She asked her husband if he would mind slipping into female apparel so she could complete her magazine illustration. That moment marked the birth of “Lili Elbe,” a model who brought fame to Gerda and her paintings of this beautiful enigmatic “woman.” Years later, there was a brief flurry of scandal when it was revealed that Gerda’s most striking model was, in fact, her husband, but by this time, Einar was passing successfully as a woman in the streets and social circles of Europe.

It’s a fascinating story, but if you believe Hallstrom, that’s not the primary reason he took on the project. Neither was story the main reason he took on the new film version of author Nicholas Sparks’s bestselling novel, Dear John, which is now in theatres.

“It’s really character that’s more important,” Hallstrom says. In fact, he often avoids stories that are too plot-driven, because of his weakness for sacrificing character for plot. People, he insists, interest him the most.

“Any story that brings people who have that irrational human behaviour and may seem odd, but ring true, emotionally. When you have that, I’m drawn to into it. I’m excited about making the film.”

That credo served Hallstrom well when he brought the sprawling human canvas of John Irving’s The Cider House Rules to the screen, when he unleashed the youthful talents of Johnny Depp and Leonardo DiCaprio in What’s Eating Gilbert Grape, and when he examined the psychology of a con artist in the recent Hoax. It’s also what drove him to accept the challenge of The Danish Girl and led to his rewarding experience with the current Dear John, in which he and stars Amanda Seyfried and Channing Tatum worked to convince audiences that this was a lot more than just a conventional love story.

Dear John deals with the intense love between a career soldier (Tatum) and a wealthy Southern girl (Seyfried) and how it’s fractured by the fact that they occupy two different words. It also has a memorable sub-plot involving Tatum’s relationship with his loving but remote father, played by Richard Jenkins.

Hallstrom says he always wants to ensure strong emotions in his films – “and not step into sentimentality when I don’t have to.

“If I have contributed here at all – having stayed on the right side of the line – I think it’s because we’ve been trying to be as honest as possible with the performances.”

So The Danish Girl will definitely be a study in character, because that’s what Hallstrom is happiest doing.

“I’m really driven to strong sentiment, but I personally hate sentimentality, and I think the honesty of the performances is what really helps you. It feels real to me, and I work hard to make it real.”