Hedwig tells her friends she got a coat from "Canada," mocking another woman who thought she meant the country. Kanada was the name given to Auschwitz's vast storehouse of goods confiscated from the prisoners.
Director Jonathan Glazer used up to five fixed cameras in the house and garden with no visible crew to capture many scenes so the actors didn't know if they were being shot in a close-up or wide shot. They were totally immersed in the scene and enjoyed working in that realistic environment.
Due to the unconventional multi-camera set up, Glazer and his team had over 800 hours of raw footage at the start of the editing process.
Jonathan Glazer did not want the atrocities occurring inside the camp to be seen, only heard. He described the film's sound as "the other film" and "arguably, *the* film". To that end, sound designer Johnnie Burn compiled a 600-page document containing relevant events at Auschwitz, testimonies from witnesses, and a large map of the camp so that the distance and echoes of the sounds could be properly determined. He spent a year building a sound library before filming began, which included sounds of manufacturing machinery, crematoria, furnaces, boots, period-accurate gunfire, trains, dogs, and human sounds of pain. He continued building the library well into the shoot and post-production. As many of the new arrivals at Auschwitz at the time were French, Burn sourced their voices from protests and riots in Paris in 2022. The sounds of drunken Auschwitz guards were sourced at the Reeperbahn in Hamburg.
In a 2023 interview with Vanity Fair, Jonathan Glazer spoke about the real-life origin of the little girl character who leaves food for the prisoners overnight and detailed the process of shooting those scenes with a thermal camera: "This girl is playing a woman, Alexandra, who I met when she was 90 years old. When I started going to Auschwitz and I started thinking about this film, obviously everything you're dealing with is pitch black. The horrors of it all are very oppressive even to think about, and there were many times during the evolution of this project that I felt I couldn't continue with it because it was nothing but darkness. A friend and one of the co-producers, Bartek Rainski, started to research people who still lived in that area, who were alive at the time-and in fact some of them were children who were basically partisans, working with a resistance movement called the AK that was the sort of Polish underground. They were running documents and they were sharing information in and out of the camps. Because they were children, they were suspected less. I met this lady and she told me her story, which was what you see in the film: As a girl, she actually worked in a coal mine, but wasn't actually down the mine. She was a local Polish, non-Jewish girl who lived locally and felt compelled to do what she could for prisoners. And part of the thing she did was to leave food for them in construction sites at night, where she was less in danger than she would've been obviously during the day... We've talked about the film being seen through a 21st century lens. It was about making sure that all of the cameras needed to be as sharp and unadorned as possible, not using lights. We didn't use film lighting-and as a result, you're then working within the limitations that you've set yourself. So you have a scene like this: Here's a girl at night in 1943, in a construction site that was full of slave labor during the day. How are you going to see her if you can't use lights? There's no ambient light anywhere near that you could justify. Lukasz Zal and I talked about how we could see her. Really, it just came down to: What's the only tool that exists where we'll be able to see something that our eyes couldn't? That was a thermal camera. Then we went on a long and very difficult journey into that technology in order to capture this sequence.
You're not seeing light recorded here. You're seeing heat recorded. I suppose it's a pretty dramatic shift in imagery from everything you've seen up until this sequence, but it's presented with the same intention, with the same commitment to the dogma of 21st century tools, 21st century lens. It's present tense. The aesthetic follows the fundamentals of it-there's something very beautiful and poetic about the fact that it is heat, and she does glow. It reinforces the idea of her as an energy."