I recently had the opportunity to witness my first ultra high-speed shoot with French cinematographer Didier Daubeach.
I asked Didier about his approaches to very high speed shoots, and his recommendations for techniques. I share his insights here, illustrated by clips from the cinematographer’s work in the first of 2 posts.
Didier Daubeach is a French cinematographer who is a specialist in high-speed cinematography. Didier has worked on commercials with prestigious products like Dior, Louis Vuitton, Mercedes, Renault, Michelin, L’oréal, Orange, Siemens, Canal+, Ricard, Bacardi, Kit Kat, McDonald’s, Pepsi, Coca-Cola...
ultra vs normal
As a viewer, I distinguish 2 different kinds of slow motion: normal and ultra. With normal slow motion you're seeing something you normally perceive, only slower. This is true of many modern shoot out sequences. You know, the scene where our hero dives beneath a hail of bullets while glass windows shatter around him. This used to be shot at 150 fps in 35mm film, but with the Red Epic, filmmakers can shoot 2K at 300 fps without switching cameras.
Around 500 or 1000 fps, depending on the subject matter, slow motion crosses the border from normal to ultra, which I define as showing something you can't perceive. Ultra slow motion reveals a new temporal viewpoint. "You can see the invisible, says Didier. You discover things that are hidden from your normal gaze in physical phenomena, and that’s truly fascinating. There’s a real poetry that comes out of what we don’t see, that comes from freezing time."
Didier gives an example from a spec commercial for Fillico bottled water that he lit and directed . Watch for the ball of water in mid-air, a good example of the invisible phenomena revealed by ultra high-speed photography. There are two links to the clip, one with audio from Didier's web site, and a higher-res version without audio:
(but without audio)
High-speed cinematography requires special cameras. Didier reminds me that with 35mm film, the high speed reference was the Arri III, and then the Arri 435 which could shoot at 150 fps. Photosonics also provided up to 3250 fps cameras with rotating prisms, in 16mm, 35mm and even 70mm. Photosonics shoots were complex affairs that burned a lot of film.
High-speed was revolutionized by the advent of digital cameras, which gave filmmakers instant feedback, and brought the ultra slow motion look into the mainstream. The most common very high speed digital camera is the Phantom, and it is increasingly used on feature films, in addition to commercials. Didier shoots with a comparable, less well-known camera, the Photron, which can deliver 2000 frames per second in 2K or HD resolution. The Photron can also record higher speeds, but at lower resolution, for example 5000 images per second at 1024 x 720 resolution.
The first obvious difference about shooting high-speed is the trigger. Digital high speed cameras contain image buffers that are continually replenished while the camera is running, and then frozen when triggered. In the case of the Photron you get a little more than 5 seconds of real time at 2000 fps. The operator has to push a button to define either the beginning, the middle or the end of that 5 second interval. So the director gets to say “Start” or “Cut” but not both. “The trigger, says Didier, is usually set for the end. For example with things falling, it's often the impact that interest you, the corolla, rather than the object itself.”
Novice high-speeders often ask Didier what speed they should select for different shots. He smiles and explains: “once they’ve seen 2000 fps, most people will stay with that for the shoot.” While 2000 fps is sufficient for many falling liquids and objects, some phenomena require more. The balloon below was shot at 5000 fps. “The best explosions are at 10 000 fps” Didier adds, adding that “it’s very difficult to get a bullet without motion blur.”
To get a closer look at the water balloons, we repeated the various bursts in this clip. The first shot of the black water balloon bursting on a black floor was filmed at 5000 fps at a reduced resolution of 1024 by 720 pixels.
You can also watch this on YouTube
“There are 3 ways, explains Didier, to burst a water balloon: with a sharp object, by shooting a BB gun or with a detonator inside the balloon. And each impact is different.” The clip includes examples of the first two: the balloon in mid-air is shot with a BB gun. “The rubber of the balloon disappears faster than gravity.”
“When you’re shooting high-speed, the problem is usually the exposure. This shot was the hardest configuration for the camera: a black balloon bursting on black plexiglass. But this dark setting allows you to see the water better. After impact, you get a tidal wave effect, because the water is constrained by the ground.” For lighting, Didier used an HMI 18K through full 216 diffusion as a frontal key, with 4 6Ks PARs on the sides, to give a sparkle to the billowing water. “I always try to use diffused lighting, says he, to minimize bright spots in the image.”
There are several shots in the spec commercial of a woman in mid-air, which we've gathered in this clip:
You can also watch this on YouTube
How do you make a woman fly? Filmmakers often use wires at normal speed, but for high-speed you only need a moment in mid-air, so Didier likes to use a trampoline. Before shooting, the actress had several training sessions on a trampoline, so that she could perform easily on the day of the shoot. Didier shot the first shot at 1000 fps, the other shots were at 2000 fps. As you can see one of the takes is played upside down.
lighting different speeds
The spec commercial also contains relatively low speed shots, like the wide shot of the woman twirling in a room full of black balloons, shot at 50 fps. Didier wanted to “mix different rhythms. The hardest thing for me is to match the lighting between 2000 fps and 25 fps. When you go from one speed to the other, you usually have to change all the lighting. There are other techniques, like playing with the shutter or adding ND, if you can’t find other solutions. Also you tend to light differently for 2000 fps where you’re focusing on action, then at 50 fps where you’re dealing with the emotion of a face, for example. You’re not going to get the emotion you want if you stick an 18K in someone’s face!”
Didier rates the Photron at 800 ISO with a 180 degree shutter, or 1600 ISO with a 360 degree shutter. “I mostly shoot with a 360 degree shutter, unless there’s something going very very fast, and I want to avoid motion blur.” Didier explains that there is a huge exposure difference between 25 fps and 2000 fps: “each doubling of the fps is 1 stop, but actually 25 fps at 180 is equivalent to 50 fps at 360 degrees. So the jump from 25 fps to 1600 is actually about 5 stops, a little more for 2000 fps.”
Didier acknowledges that he often shoots with a wide open aperture. "If you’re at T2 on a wide shot, it looks nice to have a reduced depth of field. It’s aesthetically pleasing because you’re separating the character from the background, which looks cinematic. But if you’re doing a close-up on a product or an object that won’t work as well. Especially when you're using a macro lens, a very narrow depth of field can be a problem. So you’ll need to close down to T5.6, T8 or even T11, at 2000 fps the lighting can get very difficult."
We end part 1 with this lighting challenge. In part 2, Didier will give us detailed example of ultra high-speed photography involving tires and water...
Didier Daubeach's web page
Vision Research, makers of the Phantom camera