The Cinematography of “Alder”

Back in February 2019 I spent a long day in Black Park, a forest behind Pinewood Studio, shooting a short film called Alder for director Vanda Ladeira. A little late perhaps, but here are my reflections on the cinematography and general experience of making this experimental fairytale.

The film is about a forager (Odne Stenseth) who does not realise he is being watched by the very spirit of the forest, the titular Alder (Libby Welsh). As he cuts a sprig of holly, or steps on a mushroom, he is unknowingly causing her pain. Meanwhile a group of ghosts – Alder’s former victims? – cavort in the woodland, and strips of film made with ground-up human bone reach out from the trees to ensnare the forager.

Vanda contacted me after seeing my work on Ren: The Girl with the Mark. She was keen for Alder’s lair to have the same feel as Karn’s house in that series. We had a number of meetings to discuss the tone, visuals and the logistics of the shoot, which initially was going to take place over two days but was eventually compressed to one.

In October 2018 we conducted a recce in a forest that we ultimately weren’t able to use. I remember at the time that I was considering shooting the project on celluloid, tying in with the plot point about Alder making film from her victims’ bones. I dropped the idea after taking light readings on that recce – when it was very overcast – and realising just how dark it could be under the tree canopy.

We ultimately shot on a Blackmagic Ursa Mini and Xeen primes, provided along with the lighting kit by gaffer Jeremy Dawson. The Blackmagic sensors seem to do very well with earthy tones, as I noticed on the village set of Ren, and the Ursa rendered the browns of the bracken, the soil and the forager’s costume nicely. Jeremy also provided us with a jib which enabled us to underscore the forager’s action with some definite moves: an introductory crane down; a dramatic pull up as he drives his knife into a tree; and a frantic boom down with him as he searches for his lost compass. In Alder’s lair we kept the camera drifting from side to side or up and down to bring energy to her more static scenes.

Lighting for the forager’s scenes was all natural, with just a little bounce or negative fill from time to time to keep some shape to the image. An Artem smoke gun, operated by Claire Finn, was used on almost every shot to give the forest some life and mystery, and also to keep the backgrounds from getting too busy; the grey wall of smoke serves to fade the background slightly, keeping the eye focused on the foreground action.

As there was no dialogue, I was free to change the frame rate expressively. Examples include: over-cranking close-ups of the forager’s feet and hands in contact with nature, emphasing the sensuality of his unwitting connection to Alder; over-cranking the dance of the ghosts to make their movements even more beautiful and supernatural; and under-cranking the forager slightly to enhance his panic when he finds himself lost and surrounded.

Alder’s lair was a set built by Denisa Dumitrescu in the forest. I took broadly the same approach to lighting it as I had for the reference scene from Ren, making some holes in the branch-covered roof and shining a blinder (a bank of four LED spotlights) through it to produce dappled shafts of sunlight. On the floor around Alder were a number of candles; we beefed up the light from these by skipping an 800W tungsten lamp off a bounce board on the floor.

The biggest challenge was the meeting between the two main characters, a scene scripted for daylight which we were forced to shoot after dark due to running behind schedule. It was the longest and most important scene in the film and suddenly the cinematography had to be completely improvised. We did not have anywhere near the lighting package that a woodland night exterior normally calls for – just 800W tungsten lamps, a few LED fixtures, and a generator only powerful enough to run one of each.

What I ended up doing was putting an 800 in the background, ostensibly as a setting sun, and bouncing a blinder off poly-board as fill. We shot the whole scene through in a single handheld shot, once with smoke and once without, then picked up a few close-ups.I tried to hide the lack of light in the background by allowing the 800 to flare the lens and render the smoke almost impenetrable at times. Vanda and her editor, Tom Chandler, leant into the strange, stylised look and bravely intercut the smoky and smokeless takes. The result is much more magical and expressive than what we would have shot if we had still had daylight.

You can watch the finished film here. It won me Best Cinematographer at the New York Cinematography Awards (August 2019) and Film Craft Award: Cinematography at Play Short International Film Awards (2019).

The Cinematography of “Alder”

The Science of Smoke

Smoke, haze, atmos, whatever you want to call it, anyone who knows me knows that I’m a big fan. But how does it work and what is the purpose of smoking up a set?

 

Aerial perspective

At the most basic level, smoke simulates a natural phenomenon called aerial perspective. If you look at – for example – a range of mountains receding into the distance, the further mountains will appear bluer, lighter, less contrasty and less colour-saturated than the nearer mountains.

An example of aerial perspective

This effect is due to light being scattered by particles naturally suspended in the air, and by molecules of the air itself. It is described by the scary-looking Rayleigh Equation:

We don’t need to get into what all the variables stand for, but there are a few things worth noting:

  • The symbol on the far right represents the angle between the incident light and the scattered light. In practice this means that the more you shoot into the sun – the more the air you’re photographing is backlit – the more scattering there will be. Place the sun behind your camera and scattering will be minimal.
  • is the distance from the particle that’s doing the scattering, so you can see that scattering increases with distance as per the Inverse Square Law.
  • Lamda (the sort of upside-down y next to the x) is the wavelength of the light, so the shorter the wavelength, the more scattering. This is why things look bluer with distance: blue light has a shorter wavelength and so is scattered more. It’s also why shooting through an ultraviolet filter reduces the appearance of aerial perspective/atmospheric haze.

 

How smoke works

An Artem smoke gun

Foggers, hazers and smoke machines simulate aerial perspective by adding suspended particles to the air. These particles start off as smoke fluid (a.k.a. “fog juice”) which is made of mineral oil, or of a combination of water and glycol/glycerin.

In a smoke machine or gas-powered smoke gun (like the Artem), smoke fluid is pushed into a heat exchanger which vaporises it. When the vapour makes contact with the colder air, it condenses to form fog.

A hazer uses compression rather than heat to vaporise the fluid, meaning you don’t have to wait for the machine to heat up. The particles are smaller, making for a more subtle and longer-lasting effect.

As a general rule, you should use only hazers for interior cinematography, unless there is a story reason for smoke to be present in the scene. Outdoors, however, hazers are ineffective. An Artem or two will work well for smaller exterior scenes; for larger ones, a Tube of Death is the best solution. This is a long, plastic inflatable tube with regularly-spaced holes, with a fan and a smoke machine (usually electric) at the end. It ensures that smoke is distributed fairly evenly over a large area.

A Tube of Death in action on the set of “The Little Mermaid”

 

The effects of smoke

Just like aerial perspective, smoke/haze separates the background from the foreground, as the background has more smoke between it and the camera. The background becomes brighter, less contrasty, less saturated and (depending on the type of smoke) bluer, making the foreground stand out against it.

Since smoke also obeys the Rayleigh Equation, it shows up best when it’s backlit, a bit when it’s side-lit and barely at all when front-lit.

Here are some of the other things that smoke achieves:

  • It diffuses the image, particularly things further away from camera.
  • It lowers contrast.
  • It brightens the image.
  • It lifts the shadows by scattering light into them.
  • If it’s sufficiently thick, and particularly if it’s smoke rather than haze, it adds movement and texture to the image, which helps to make sets look less fake.
  • It volumises the light, showing up clear shafts of hard light and diffuse pools of soft light. (For more on this, read 5 Tips for Perfect Shafts of Light.)
  • Backlit smoke in front of a person or an object will obscure them, concealing identity.
Heavy smoke (from an Artem) pops Lyanna (Dita Tantang) out of the background in “Ren: The Girl with the Mark” (dir. Kate Madison).
Backlit smoke through a roof of branches creates magical shafts of light in “Ren: The Girl with the Mark”.
The final day/sunset look. From each side an orange-gelled and a pink-gelled par can light the backdrop. A 2K tungsten fresnel provides backlight, while a 650W fresnel with a cucoloris provides dappled light on the tree and tarsier. An LED panel off right supplies fill, and a second panel is inside the cave with a turquoise gel.
The colour-washed infinity cove in the background of this music promo for Lewis Watson’s “Droplets” (dir. Tom Walsh) is softened and disguised by smoke.
Haze gives the LED panels their glowing appearance in this video for “X, Y & Z Rays” (dir. Tom Walsh) by Revenge of Calculon.
This torch beam in “Above the Clouds” (dir. Leon Chambers) shows up so well because the set is heavily fogged.
Smoke backlit by an HMI creates the blue background glow against which the heroes of “The First Musketeer” (dir. Harriet Sams) stand out.
Haze creates the shafts of light from HMIs outside the windows, and adds to the gothic feel of “Heretiks” (dir. Paul Hyett).
The Science of Smoke