To film at 1000 frames per second (FPS) requires a well-thought-out workflow concerning both data volumes and lighting. To capture this many frames per second, an immense amount of lighting capacity is needed.
During this year's biggest fashion industry event, the Costume Awards, we filmed using what's known as a "glambot". We used a Phantom Flex 4K camera, capable of shooting at 1000 FPS, mounted on the Bolt Jr+ robot. By capturing such a high number of frames per second, we could later transform the footage into stunning slow-motion shots. Our goal was to provide the guests with access to these clips on the very same evening, so we had an editor working on post-production while we continued filming throughout the night.
The shoot took place at Ekebergrestauranten, and during our pre-shoot inspection, we discovered that there wasn't sufficient electrical capacity on-site to complete the recording.
A high-speed recording demands an incredible amount of light because the camera shutter operates very rapidly. We had the camera set to 950 FPS, a 180-degree shutter angle, an ISO of 800 (native), and a fast wide-angle lens, specifically the Angenieux EZ-2 15-40mm T2/FF.
Normally, it's recommended to use HMI lights for productions of this kind. They are flicker-free and provide soft, even illumination. HMI lights have been a staple in film production for years but come with certain limitations:
Size and Power: These lights are large and consume an incredible amount of power. In the past, we used an 18K Arri HMI, which draws 18,000 watts of power and requires a location with a 3-phase 400 Volt power supply.
Diffusion: HMI lights require a substantial diffusion scrim, which must be positioned at some distance from the light. This scrim needs to be secured against wind and occupies a significant amount of space on location.
Heat Emission: HMI lights generate a significant amount of heat, and they cannot be turned on and off frequently. The gas bulb in the light must cool down before the light can be re-ignited.
After several days of testing, we arrived at a solution we felt confident in. Our lighting rig became a combination of HMI lights and LED panels.
As our main light source, we used a Dedolight DPB79 Parallel Beam Light. This is a 1200W HMI lamp with a focused and concentrated beam of light, somewhat reminiscent of what you might see in Batman movies. Using one of their specially crafted Dedolight mirrors, we reflected the light and directed it back onto the subject. Dedolight offers different mirrors to achieve various light fall-off effects. These mirrors range from 1 to 4, with mirror 4 being the softest and providing the broadest light spread. After conducting our tests, we determined that Mirror 3 was the most suitable choice for this production.
To fill the area around the subject, we utilized two Lightstar LUXED-12-LM-Brute lights. These lights are LED bulbs positioned above a large panel. One should not underestimate the power of these lights. With the included softboxes, you can create a large light source conveniently placed on a single combo stand.
Note: Exercise caution when dimming the lights while shooting at high speed, as it may introduce "flicker" into the image. It's better to soften the light using a softbox or other forms of diffusion rather than dimming.
One of the significant advantages of the Lightstar lamps is their portability. They can easily be rolled around and placed in corners, making them suitable for locations with limited space. Additionally, they have a low power draw, consuming only 2160 watts per lamp. It's clear that LED technology is advancing rapidly, and even for demanding shoots like Glambot recordings, LED lights can be a viable solution.
File Handling: The Phantom Flex utilizes specially designed SSD cards and has built-in cache memory capable of storing up to 6 seconds of footage at a time. This data must then be written to the card. When the camera is writing to the card, it's not operational, but this process is relatively quick, taking around 30 seconds per clip.
Everything is controlled through Vision Research's proprietary software via an Ethernet cable connecting the camera to a computer. This software only functions on Windows machines. The cards have a capacity of 1TB, but since we needed to deliver files quickly to the editor, we only filled the cards halfway. The files were then transferred to an SSD drive and handed over to the editor.
Note: To transfer files through a Mac computer, you need third-party software that supports file transfer from the card to the Mac and then to the SSD drive. You can purchase an annual or weekly license for this software, typically costing around $150 for seven days. The editor then had to transcode the Phantom Raw files into a format compatible with Premiere, in our case, ProRes 4444. DaVinci Resolve is the only software capable of reading Phantom Flex files, so it's essential to have it on your computer.
We hope this article provides you with valuable information that will be beneficial in your upcoming film production. Please feel free to reach out to us if you have any questions regarding the use of high-speed filming techniques.