The Photographer of Mauthausen Reveals the Extraordinary True Story of Francesc Boix — Who Smuggled 2,000 Nazi Negatives Out of the Camp

Behind the harrowing events depicted in The Photographer of Mauthausen lies an extraordinary true story: a young Spanish prisoner who helped preserve thousands of photographs documenting Nazi crimes and ensured that evidence survived beyond the walls of the concentration camp.

Directed by Mar Targarona, the 2018 Spanish historical drama follows Francesc Boix, a Catalan photographer imprisoned at Mauthausen during World War II.

Boix was barely 20 when he arrived at the camp after the fall of the Spanish Republic, his subsequent exile and the German invasion of France. He had been captured following the defeat of the French army.

What happened afterward transformed photography into far more than his profession.

It became a means of survival, resistance — and eventually evidence.

Boix helped save around 2,000 negatives

At the center of the film is Boix’s involvement in preserving photographic records from Mauthausen.

According to director Mar Targarona, photography is “the heart of the film.”

Boix and others managed to hide approximately 2,000 negatives documenting what happened inside the concentration camp and ultimately smuggle them out.

Those images would become historically significant.

The negatives provided evidence of the horrors committed at Mauthausen and later played a decisive role in the Nuremberg Trials.

Targarona was particularly struck by the unsettling fact that the Nazi system had extensively documented its own activities.

“What the Nazis did was all documented, despite all that they burned,” she explained.

“And it’s chilling to see. Most of all, seeing how naturally the Nazis themselves assumed their role.”

That idea became the foundation of the film.

Rather than telling another broad story about World War II, Targarona wanted to examine one specific chapter through the man whose photographs helped preserve it.

Thousands of Spanish prisoners were sent to Mauthausen

One of Targarona’s motivations was how little known the experiences of Spanish prisoners at Mauthausen remained in Spain.

The director had long been fascinated by World War II and Nazism and had spent years watching films and documentaries about the period.

When screenwriters Alfred Pérez-Fargas and Roger Danés brought Boix’s story to her attention, she immediately recognized its potential.

“I said to them, ‘Go for it!’” she recalled.

That began approximately four years of research and development.

The deeper the filmmakers investigated, the more material they uncovered.

Targarona said many people in Spain remained unaware that thousands of Spaniards had been imprisoned at Mauthausen.

Exact figures differ depending on the source, but she estimated that around 7,500 Spanish prisoners were sent there, with approximately 2,000 surviving.

That largely overlooked Spanish experience became essential to the film’s identity.

The filmmakers wanted to avoid making ‘a vague mosaic’

Targarona was conscious that countless films had already examined the Nazi era and concentration camps.

To justify telling another story, she believed The Photographer of Mauthausen needed a precise perspective.

“I have focused on one very specific, unexplored topic — the Spanish,” she explained.

Within that history, Boix became the central figure.

When the filmmakers travelled to Mauthausen as part of their research, they discovered that the photographer was far better known there than he was to many people in Spain.

Targarona said Boix was recognized in Austria and noted that there was even a small monument at the home of Mrs. Pointner, where negatives had once been hidden.

Boix therefore became the narrative thread capable of connecting the larger historical events.

Establishing that focus early was crucial, Targarona explained, because she did not want the movie to become “a vague mosaic in the infinity of films on the topic.”

Mario Casas lost nearly 40 pounds to play Boix

Spanish actor Mario Casas took on the demanding role of Francesc Boix.

Known for projects including The Mule and Palm Trees in the Snow, Casas reportedly lost almost 40 pounds in preparation for filming.

The filmmakers also faced the difficult task of transforming a complicated real person into a character who could carry a feature film.

Research became essential.

One particularly important source was Benito Bermejo’s book The Photographer of Horror.

Targarona described the book as an “irreplaceable help,” while Bermejo himself collaborated with the production during both writing and filming.

The team also consulted Montserrat Roig’s Catalans at Nazi Camps and information collected by Spanish deportees.

Because of the enormous amount of historical material available, some characters became composites based on several real people.

Boix himself also had to be condensed for dramatic purposes.

The real Boix was more than a solemn historical figure

The research allowed Targarona to develop a more rounded picture of the young photographer.

Rather than portraying him simply as a permanently grave figure moving through horrific circumstances, she discovered someone with a distinct personality.

Targarona described Boix as friendly, mischievous, intelligent and fundamentally a survivor.

He also possessed a degree of arrogance and self-confidence.

Those qualities were important because they helped turn him from a historical name into a recognizable young man.

The film’s first-person perspective consequently depends heavily on viewers understanding Boix not merely as a witness to history, but as someone attempting to navigate and survive it.

The film deliberately rejected the usual ‘grainy’ historical look

Targarona also made a deliberate visual decision that separates The Photographer of Mauthausen from many period dramas.

She did not want the movie to look artificially old.

“I can’t stand the idea that relates making a historical film and automatically adding grain and killing the color,” she said.

Instead, she and cinematographer Aitor Mantxola wanted imagery that felt realistic, precise and visually rich.

The approach avoided handheld camerawork, with shots carefully constructed rather than deliberately made to look unstable or archival.

Production designer Rosa Ros worked closely with Mantxola to create the historical environment with rigorous attention to detail.

The result was intended to make the past feel immediate rather than safely distant.

That decision becomes especially important when the movie recreates photographs associated with the real history.

Photography becomes an act of resistance

Ultimately, The Photographer of Mauthausen is not simply a survival story.

Its central theme is evidence.

Boix understood that photographs could preserve what people might later attempt to erase or deny.

The images survived when many other records did not.

They left the camp.

And eventually, they became part of the process of holding Nazi officials accountable.

That gives the movie an unusual perspective on resistance.

Boix’s most important weapon is not physical force. It is the preservation of visual truth.

The photographs shown during the film’s credits further connect the dramatized story with the historical evidence behind it.

For Targarona, that relationship between image and truth was fundamental.

“Photography saves Boix,” she explained, “and serves, in the end, to bring justice.”

The true story makes the film even harder to forget

The Photographer of Mauthausen was produced by Barcelona-based Rodar y Rodar in partnership with Netflix, We Produce 2017 AIE and Hungary’s Filmteam, with support from Spanish broadcaster RTVE and Catalan broadcaster TVC.

The movie was released theatrically in Spain on October 26, 2018, before becoming available on Netflix in February 2019.

For Targarona, it followed years working as a producer on films including Juan Antonio Bayona’s The Orphanage and Oriol Paulo’s The Body, while marking her second feature as a director.

But the significance of The Photographer of Mauthausen ultimately lies beyond its production history.

It brings wider attention to Spanish prisoners whose experiences in Nazi concentration camps remained unfamiliar to many people — and to a young photographer who understood that surviving evidence could matter almost as much as surviving himself.

Francesc Boix helped ensure thousands of images escaped Mauthausen.

Decades later, those photographs continue doing exactly what he risked so much to make possible: bearing witness.