Björn Charpentier on crafting practical movie magic in Whistle

Whistle is the latest horror feature from director Corin Hardy, following The Hallow(2015) and The Nun (2018). The story follows a group of students who unearth an Aztec Death Whistle and discover that the sound it emits will summon their future deaths to hunt them down. The film sees Hardy reunite with cinematographer Björn Charpentier, having previously collaborated on the acclaimed TV series Gangs of London. 

Hardy already had several films in mind as references when he discussed the project with Charpentier. “I don’t usually look at a mood board with the director,” begins Charpentier. “I don’t want to go into all those details straight away. I prefer to create my own mood board first to see what vision I have in mind. From there, I can compare notes with the director.” 

Charpentier argues that working this way opens up more possibilities. “Otherwise, you go down a certain path, so this allows for new ideas,” he says. “You can compare notes and at least there’s a good stepping stone to the next step of the visual style of it. That’s always a process I like to do.”

Charpentier admits that after reading the script he immediately knew how he was going to lens the project and how Whistle would look visually. “Lighting-wise, it was more of a search for me. I knew how to lens it, but not how to light it.”

Visual References 

During prep, Charpentier and Hardy shared a house. “We spent six weeks basically living together. This was so much fun, because you live the project through and through andyou keep talking about it. We watched so many movies together on the weekends. There was a big TV and we screened all these movies.” 

The Breakfast Club (1985) was a film they both looked at as it involves several characters with different backgrounds all coming together. The Lost Boys (1987) served as the main reference and is also one of Hardy’s favourite films. The two also revisited King Kong (1933), Creature from the Black Lagoon (1954), The Blob (1958) and A Elm Street 3: Dream Warriors (1987).

“We wanted to do as much as possible in camera,” explains Charpentier. “Going back to those older films showed us how much could be achieved practically without relying heavily on visual effects. We wanted to make it very artisanal in a way and it was very inspiring to see all of those old movies again.” 

There were a few visual effects that made it into the final film, however, where it wasn’t possible to achieve the required effects practically. “The scene where Mr. Craven’s (played by Nick Frost) face changes was inspired by the Mission Impossible films,” he says. “We did that with the real Nick Frost and then with the prosthetic Nick Frost. The problem was we couldn’t move the teacher’s bench at our location, which ultimately meant I couldn’t do a 360-degree tracking shot.”

To combat this, Charpentier explains that they had Nick Frost stand in the gym with green screen around him and then shot it 360 and lit it the same way so it matched. “On the relocation, we just styled the classroom and stitched it together. So that was one of our VFX shots.” 

Fairground Thrills 

The fairground scene was shot on location, although they decided to build the maze on stage. “We had nine days for that scene,” says Charpentier. “We were shooting acrosswinter late 2023 and early 2024 and so we were unsure about the weather. The set was constructed in a hangar and the ceiling was no more than 20 feet high. We couldn’t really hang a lot on the ceiling because of this.”

Instead, the crew decided to use the ceiling as a bounce board. “We projected a lot of lights onto the ceiling and bounced the light back,” explains Charpentier. “Whenever we saw above the hay bales in the shots, we just put black screens in. For example, whenthe crone is on top of the hay bale and we see the big Ferris Wheel in the background, that was blue key because we did plates on the location and we knew we’d be shooting into the sky. For some of those shots we had blue key because there was no way around it. Otherwise, everything was done in camera.”

Charpentier notes that the process involved utilising miniature shoots, split diopters, as well as dolly zooms. “We did all of that on set,” he adds. “We wanted to rely on immediate effects on camera.” 

An example of when they blended these techniques is when the crone crawls vertically down one of the hay bales. “We had several units,” says Charpentier. “We shot the hay bales as a plate, then we took one of the hay bales and we put it flat on the floor and then the actress crawled backwards and we reversed speed and tilted vertically, which is how we achieved the effect.”

The effect was also influenced by Bram Stoker’s Dracula (1992). “We had actors walking backwards and then reverse speed in edit and the whole movement of the joints feels different. It’s not as smooth, which makes it eerie. We also had a contortionist on set, so when the crone crawls up the hay bale, it was actually stunt artists performing the movement.”

Lighting through Music 

The inspiration for the lighting came through music, which Charpentier admits was a first. “Corin put together a playlist of music that inspired the tone for the movie,” he says. “There was a song on it that I really loved called King Night by SALEM. It was originally meant to be used for the Harvest Fest sequence. I was always playing it loudly in my office to help me stay in the zone, much to everyone else’s annoyance. In the end we didn’t use it.” 

Charpentier explains that the music would occasionally be too strong for the mics to hold, which resulted in a distorted sound. “It was those imperfections that Corin really loved,” he says. “That essentially triggered the way I needed to light the film. I didn’t want to go for perfection and realised we could play around with it. In the Harvest Fest scene, we had so much light pollution from all the various attractions. We did have two big cranes so we could direct some light, but once Grace and Dean are inside the mazethe lighting is more saturated. The deeper they go, the more neutral it became. I wanted to evolve the look, so at the beginning you see more practicals inside the hay bales and the deeper you go it gets darker and darker.” 

As the two characters enter the maze at different times the lighting is distinguished to reflect where they both are within the maze. “It was a nice visual playground to identify where each character was,” says Charpentier. “We also discussed how the tunnel would look, for when they go into the tunnel right before they ring the bell. We spoke about it at length to decide whether it should be a closed environment, or a circle or square.”

Production Designer, Jennifer Spence came up with the idea of making a square box with wooden planks with gaps in between, so light could still shine through. “My gaffer, Dimmer Board Operator and I tried to find a nice light effect we could use,” he says. “We had several four foot strips of light with LED bulbs in it and we spent lots of time playing with that effect. At one point we have Grace crawling through the tunnel, but the crone is crawling backwards on the ceiling. We had to trick that, so we had her crawl on the floor as well, but we swapped the light. It was all done in camera. The tunnel was maybe 23 feet, but because the light is moving, it looks endless. Shooting it was the stuff of proper nightmares.”

Charpentier enjoyed the freedom in being able to light each scene differently. He points to the memento mori room as a primary example. “When the characters discover the history of the whistle, we could play around with the contrast. We made it more single source in a way that a Rembrandt painting would be. Of course, we wanted to be mindful of shadows, but every scene had its own inspiration. We were able to shift depending on what we needed scene wise.” 

The first horror sequence shot was the post-basketball sequence which was lit at night. “I wanted to do something graphical with red light,” admits Charpentier. “Everyone was questioning the red light and I didn’t have an explanation, it just felt right. The school has this red kind of colour as well and it’s a colour that always comes back.”

Charpentier lit it that way and Hardy wasn’t sure as it was quite bold. “Corin asked to do more of a plain moonlight, but it didn’t work for me or have that edge,” he says. “I told him we needed to be bolder. My motto working on the film was ‘fortune favours the bold’ which is a line I remember from Oliver Stone’s Alexander (2004). So, we swapped back to red and everybody said it looked so cool and Corin admitted it was much better.” 

Lensing the project 

While music influenced the lighting approach, Charpentier’s lens choices were equally important in shaping the film’s visual identity. “There were six weeks of prep and six weeks of shooting to dissect the film,” he says. “I really enjoy going back to the script and analysing it and looking at each character arc. I’m always trying to see how I can tell a character’s arc through visual storytelling.” 

Another film Charpentier and Hardy saw together was The Evil Dead (1981). “We were lucky enough to see it on the big screen in Toronto,” he says. “In the film you have this fast camera going towards a character or the house and I thought we should try a lens that could visualise the sound wave of the whistle.” 

During pre-production, Charpentier had the opportunity to play around with lenses and cameras, testing which would suit the project. “For the sound wave of the whistle I was inspired by Logan (2017) when Xavier goes into epileptic shock and you see the images vibrating. We tried a few ways but they all felt too mechanical. We shot on Sony VENICE Rialto and I felt we should shoot it handheld. I wanted our lens to touch every character’s face.”

The rental house had a prototype Tokina lens that they’d built for Yellow Jackets and was the perfect fit for the effect Charpentier was after. “The centre of the image was clear and it’s smeared towards the sides,” he says. “I played with that and told them it was the right lens because it felt so organic and different. We of course changed the name to the Whistle lens. We baptised it on set as that and we used it for whenever a character blew the whistle, the spirit of the whistle is that lens basically.” 

When each character comes face to face with their death, Charpentier wanted each close-up to be visually unique. “I wanted a lens that would create a warp around the character. We finally opted for the Angenieux M1 50mm. The moment you shoot it wide open, you have this very shallow depth of field, but it felt completely different. The bokeh was so abstract it gave a sickly feeling. We used the Hawk V Lites for the main story and then we had the Hawk V-Plus Zooms as well. For the whole movie we shot mainly at a 2.8/4.”

All the underwater sequences were shot on stage in dry for wet principle. “We never went into real water,” says Charpentier. “We blacked out the studio wall and added a lot of smoke and created some light effect for the god rays of sun. We used the Alexa Mini for that and shot everything at 200fps on a technocrane that could go into matrix mode.” 

The rays of light were created by a custom box built by gaffer, David Allan. “We made a carton box with the top a silver layer of Rosco filter under 45° and we added a ventilator on it so the silver would move,” explains Charpentier. “Then we did several tests. We knew the box was going to be fixed at the ceiling, so we just needed to see how far the light on the ceiling needed to be from the box’s silver filter to have the right amount of sharpness on the actor.”

Meticulous Prepping 

Due to the amount of prep time, Charpentier acknowledges that it gave them time to solve all the problems before it came to shooting the project. “For example, the bedroom sequence with the two characters kissing required lots of planning. You can see the shadows of raindrops on their faces, which is something I really wanted to do. The location was very tricky because there was a tree just outside the window.”

Charpentier meticulously planned the sequence with his gaffer, measuring the exact distance between the wall and the actors. “We knew they would be six feet from the wall,” he says. “During prep we experimented with different lights to see how far we needed to put the light to have the right amount of sharpness. I didn’t want it to be super sharp. Once we were on location, we knew exactly how many feet away from the wall they needed to be and we also knew exactly which lights to use.” 

Working on the project was a great experience for Charpentier, which he puts down to having such a nice crew around him. “We spent a lot of time trying to find the right people,” he recalls. “That’s key to me when I work abroad, especially on a long form project. If the energy isn’t matching, then I don’t think it’s going to be a good fit. I need someone on my energy level and with the same amount of enthusiasm that I have. I want to have the same mindset as the people around me because then I feel we all do better work.”

Having previously worked with Hardy, Charpentier says there is already a trust between them. “You know what to expect and how that person works,” he concludes. “Corin is somebody with so much energy and love that the whole crew goes the extra mile without him even asking for it. There is no ego there and he knows what he needs from each department, so he’ll give people the time they need to do the work. There’s a lot of respect both ways. It was a dream project really.” 

By Oliver Webb