Interview with Martin Gschlacht, AAC, about "The Devil’s Bath", by Severin Fiala and Veronika Franz

1750. Upper Austria. Agnes, a young bride, feels like a stranger in her husband’s cold, rural world. Deeply religious and sensitive, she retreats into herself. Her inner prison becomes overwhelming, and her melancholy unbearable. She sees only one escape—a shocking act of violence.

What is striking after watching the film is the extreme realism in the historical recreation. How do you immerse yourself in 18th-century Germany as a cinematographer ?

Martin Gschlacht : Naturally, one immediately thinks of the great painters of the 17th century, like Rembrandt or Vermeer. But the film primarily relies on the work of historians’ who studied the era in southern Germany and Austria. The descriptions of the lives of these peasants, for example, scenes such as carp fishing in the river and in the mud, are very close to historical reality. The same is true of the settings, such as the Austrian forest, which we scouted during a previous short shoot (The Sinful Women of Hollfall from The Field Guide to Evil). These locations and scenarios are crucial to the film’s visuals and atmosphere.

Was that short film a kind of draft for this project ?

MG : Yes, absolutely. It was our first exploration into that time period and historical recreation, including, for example, the family house where our protagonist comes from, shown at the beginning of the film. It’s the exact same house we filmed in back in 2019. We were lucky to find it in the same condition. Regarding the main house deep in the woods where Agnes and her husband settle, our production designer discovered it. It’s an incredibly simple, raw space that immediately struck us. However, we had to secure the structure to prevent collapse and contend with the challenges of filming in a place with almost no windows. It was nearly impossible to light the space from the outside, as the walls were thick and dark. Cold too. But it suited perfectly the austere environment of this house that Agnes moves into. This was in Lower Austria, in the northeast (Waldviertel), with very peculiar, almost mystical landscapes.

How do Severin and Veronika work as directors ?

MG : They have a unique way of making films. Once the locations were selected, they spent a week on-site scouting angles and creating a preliminary breakdown—without the actors. It was like a technical rehearsal where we used a simple phone, themselves acting out scenes in front of the camera. It’s funny because I still have pretty much the entire film recorded on my phone with them acting.
This process was very useful, as it allowed us to feel each scene in situ, put things into perspective in the image, and simplify the scenography.
Later, in a second phase with the actors, they prepared them, not by focusing strictly on the script but by immersing them in their character’s psychology and situation. Dialogue wasn’t emphasized as much as the context and mood were.
For example, they asked Anja, our lead actress (in her first on-screen role), to spend several days preparing for the harsh winter cold to adjust to the film’s challenging atmosphere. She prepared by living on a small farm among animals in a rural setting similar to what her character would be experiencing. I remember all four of us spent several weekends in this small house in the woods, one of the main locations of the film. We stayed there with no phones or electricity, heating ourselves with firewood just as it would have been done during that era. It was a way to bond as a team and experience the daily lives of the film’s characters. After spending two or three days in such a cold, damp environment, cooking and keeping warm with basic tools, breathing in the fresh forest air, you become truly ready to film such a story !

Why did you decide to shoot on film ?

MG : This was my second feature-length project with them, plus the segment from The Field Guide to Evil I mentioned earlier. Since the first film we did together (Goodnight Mommy, 2014), Severin and Veronika were adamant about shooting on film. It was an especially bold decision since that film starred 11-year-old twins with no acting experience. But after comparing it to digital, the rendering of colours, skin tones, and textures with film immediately made them lean towards celluloid.
Beyond the visual appeal—which can certainly be debated given modern digital colour grading— the concentration and quiet on set during a film shoot is critical to them. The quiet hum of the camera and the rolling film commands attention from everyone. It’s fundamentally different from digital filmmaking, where the camera can roll continuously, even during rehearsals. Sometimes, even while a makeup artist is still in the frame, doing a touch up.
Severin and Veronika shoot economically, and the importance of the first takes suddenly take on a whole other meaning. I would say that they capture the essence of a scene in the first take about 90% of the time ! We rarely exceed three takes per shot, resulting in a film-to-shot ratio of about 11:1 or 12:1—a modest figure compared to modern productions. This keeps film and lab costs relatively low.

Did you have to convince the production team to approve shooting on film ?

MG : Yes, it was a challenge initially. The German co-producer claimed it would add €100,000 to the budget. However, this cost was highly over estimated, as it was based on a high shooting ratio of 16:1, which we never came close to. Plus, when it’s the directors who strongly advocate for shooting on film, it becomes easier to justify the cost.
The downside is that the production team tries to cut costs elsewhere, like choosing the cheapest lab available, which isn’t always the one you would want to work with.

Was shooting on film challenging, given its lower sensitivity compared to digital ?

MG : Everything was shot at 500 ISO with Kodak 5219. I avoided over processing, as the resulting sensitivity gain often compromises image quality. As I was mentioning earlier, the rendering with film of the colours, skin tones, and for example many of our candlelit scenes are unmatched by digital.
In terms of the lenses I chose, I equipped my Arricam with a classic lens set I often use, the Cooke S4. I tested Zeiss Master Primes during pre-production, but the Cookes’ soft yet sharp look was much more suited to this project.
Most of the time, we relied on natural light sources, when possible, primarily HMIs during daytime or dusk scenes, using the few windows and doors available. For candlelit scenes, we augmented the light with additional off-camera candles or flames to maintain the right flicker and warmth. But some scenes are incredibly dark, almost too dark—this is a film meant to be seen in a theatre, in the dark, not on a bright TV in a lit room.

How was the film shot overall ?

MG : As mentioned, the directors prepared extensively without relying on the script too much, but relied more on the actor’s improvisations during a scene. Another unique aspect, which goes hand in hand with the actor’s interpretation of scenes, was that we shot the film entirely in chronological order. Even the prologue sequence, with the mother and the child at the top of the waterfall, which we filmed a year earlier for production and budgetary reasons, fits seamlessly into the narrative.
After that, we really filmed each scene in the exact narrative order, going back and forth between the different locations, which fortunately weren’t too far apart either.
Filming chronologically really helped Anja with her character’s emotional progression. However, we had to shoot part of the film in Germany due to co-production requirements.
That was something we knew from the outset, and which gave rise to a few discussions about shooting everything in chronological order. Should we start in Germany or end the film there ?
The second option was chosen, and the transition occurs in the final act, when Agnes meets the boy and leads him to a small oratory. The forest changes visibly in this sequence, with different tree species and a reddish-brown forest floor instead of the green and cyan hues of Lower Austria.
At first, we were really worried about this visual change, but it ended up working well, and complementing Agnes’s strong character evolution. It goes to show that you always have to know how to exploit the unpredictability of the weather, or any other unforeseen events during filmmaking.

So, was the final sequence in the town square also shot in Germany ?

MG : Yes, the entire ending, including the crowd scene which was also shot there. This was one of the few times we used two cameras, capturing the action with a documentary-like approach. Most of the extras from the wedding scene earlier in the film reappear here. As it was impossible to cast people between Austria in Germany to maintain continuity, we sent 2 busses and sent everyone who had filmed with us the previous month from Vienna to Germany for the day.
It was admittedly paradoxical considering our limited budget, but authenticity remained the priority. The entire film was made on a tight budget, with a small crew, over 36 shooting days (plus two for the prologue a year earlier).

What did you take away from this film ?

MG : I was deeply moved by Anja’s performance. As a musician and singer with no prior acting experience, and in addition to all the preparatory work she did, she really carried the film from start to finish.
One unforgettable moment was the confession scene near the end. We set up a stationary camera and gave her basic framing instructions, leaving her alone for a single take on a 300-meter film roll (11 minutes with a 35mm). A video feed had been set up by the filmmakers a few meters away. Watching her performance on the video feed, I remember crying, just as the film ran out. It’s the kind of precious moment that you remember as an operator long after the filming adventure is over...

(Interview directed by François Reumont for the AFC, and translated from French by Chloé Finch)