ARRI Hi-5: The Focus Puller’s Companion
ARRI & Cine Visuals Present: ARRI Hi-5 Follow Focus
Cinematic Heritage
ARRI has long stood as one of the quiet architects of modern cinema. Founded in 1917 by August Arnold and Robert Richter in Munich, the company’s name – derived from the first two letters of each founder’s surname – has become synonymous with precision engineering and an almost obsessive commitment to filmmakers. For over a century, ARRI has built tools not merely for capturing images, but for the craft of filmmaking itself. Their philosophy has always been rooted in a simple but profound principle; listen to the people who actually use the equipment. Spend any time on a professional film set and you will hear the same sentiment repeated by cinematographers, operators, and camera assistants alike – ARRI gear just feels right. The balance of a camera body, the resistance of a focus ring, the placement of a button on a hand unit – these details rarely make headlines, yet they define the daily experience of working filmmakers and make the stories on the silver screen possible. ARRI’s success comes from understanding that filmmaking is as much a physical activity as it is mental exercise. Their engineers work closely with cinematographers, operators, and camera assistants to refine every aspect of their designs. The result is equipment that disappears into the workflow, allowing filmmakers to focus entirely on the creative process.
The craft of focus pulling has evolved alongside the tools used to capture moving images. In the earliest days of cinema, focus was often fixed or adjusted manually on the lens barrel itself. Cinematographers and operators would physically turn the focus ring from the barrel while operating the camera, a process that demanded both precision and a steady hand. As filmmaking grew more complex, productions required greater control over focus while the camera moved dynamically through space. The invention of the mechanical follow focus was the first major step forward. Mounted on rods attached to the camera, the follow focus used gears to translate movement from a large external knob to the much smaller focus ring on the lens. This allowed the focus puller, usually standing beside the camera, to perform delicate adjustments with far greater accuracy. The large knob offered a longer throw, making fine adjustments possible even on lenses with very shallow depth of field. The addition of marking discs allowed assistants to place focus marks corresponding to actor positions. Suddenly, focus pulling became a choreography – a dance in real time with the operator and actors as they moved the frame and through it.
For decades, this system defined the role of the focus puller and even the term focus puller is synonymous with 1st AC (or First Assistant Camera) in countries like the US and UK. But filmmaking itself continued to evolve. Cameras began to leave the tripod and dolly more frequently. Steadicam, cranes, car rigs, and handheld cinematography transformed how images were captured. As cameras moved farther away from the focus puller and operators controlled the camera remotely, mechanical follow focus units became more and more impractical. This challenge led to the development of wireless follow focus systems. By the late twentieth century, manufacturers began experimenting with remote motor control systems that allowed focus pullers to operate lenses from a distance. These early systems were often bulky and unreliable, but the potential was immediately clear. Wireless focus control liberated the camera from the physical limitations of cables and proximity. ARRI entered this space with their Wireless Compact Unit series, which would gradually become an industry standard. The WCU-1 and later WCU-3 introduced robust wireless motor control designed specifically for professional film sets. However, it was the WCU-4, released in 2012, that truly cemented ARRI’s reputation among focus pullers. The WCU-4 was compact, reliable, and deeply integrated with ARRI cameras and lens data systems. For nearly a decade, it became one of the most widely used wireless hand units in high-end film production.
But filmmaking never stands still. As digital cinema matured, new demands emerged. Lens metadata became increasingly important for visual effects workflows. Radio frequency environments on set grew more crowded as wireless video transmitters, lighting systems, and communications equipment proliferated. Camera systems themselves became more interconnected, with camera assistants expected to control not only focus but also iris, zoom, and camera functions from a single interface all from a remote distance of the camera. ARRI recognized that the next generation of wireless control would require a complete rethink of the hand unit itself. In 2021 they introduced the ARRI Hi-5 Follow Focus, the fifth generation of their intelligent hand units and the natural successor to the WCU-4. The Hi-5 was not simply an update but rather it was the centerpiece of an entirely new approach to electronic camera control. It is a tool shaped by the experience of countless focus pullers working long days on demanding sets. Every dial, screen, and function is built around the reality of how 1st ACs actually work. The result is a device that feels less like a piece of electronics and more like an extension of the craft itself.
Handling & Adaptability
The first thing a focus puller notices about the Hi-5 is how familiar it feels. ARRI wisely resisted the temptation to reinvent the physical form entirely. Years of muscle memory built around the WCU-4 meant that many assistants already had an intuitive understanding of how the device should sit in the hand. Instead of radical change, ARRI refined and strengthened the design. The body of the Hi-5 feels solid and purposeful. Weighing roughly 1.8 lbs or 830 grams, it strikes a balance between durability and portability. In the hand it carries enough weight to feel substantial without becoming tiresome during a long day of shooting. Anyone who has spent 12 hours pulling focus knows how important this balance is. The industrial design of the Hi-5 reflects ARRI’s deep understanding of how assistants work in the field. A built-in NATO rail along the side of the unit allows for easy mounting of accessories such as monitor brackets, rangefinder displays, or custom rigs. This seemingly small feature becomes incredibly valuable when adapting the unit for different shooting environments. On one job the Hi-5 might live in the hands of the focus puller all day; on another it may be mounted to a stand near video village alongside a monitor.
Power is supplied through ARRI’s smart battery system using the NP-L interface. These batteries slide neatly into the back of the unit, providing a runtime of roughly 12 hours under typical operating conditions. In practical terms, this was designed to allow a focus puller to comfortably run through an entire shooting day without constantly worrying about power. However, when power is drained, battery swaps are quick and painless, and the system provides clear information about remaining capacity.
Weather sealing is another crucial element of the design. The Hi-5 is both dustproof and weather resistant, which means it can confidently accompany the camera into harsh environments. Rain, desert dust, and snow are all realities of location shooting. Knowing that your hand unit can withstand those conditions brings peace of mind in moments when the rest of the set might be scrambling to protect sensitive equipment. Temperature resilience is another crucial aspect of the design. Film productions sometimes take place in extreme environments, from freezing mountain locations to scorching deserts. Not every set takes place in the mild weather of Hollywood. The Hi-5 is engineered to function reliably across a wide temperature range, ensuring that focus control remains stable even when conditions become challenging.
At the heart of the Hi-5 remains the focus knob itself. This is the tactile center of the device, the physical connection between the focus puller and the lens. ARRI designed the knob with an adjustable drag system that allows assistants to tune the resistance to their personal preference. Some prefer a light, responsive feel for fast movements, while others favor heavier resistance for precise pulls on wide-aperture lenses. The ability to adjust this resistance ensures that the unit can mimic the feel of a traditional mechanical follow focus as closely as possible.
The Hi-5 supports control of one to three motors depending on the installed license configuration. This allows focus, iris, and zoom to be managed simultaneously from a single hand unit. The radio system offers access to up to roughly one hundred channels, providing flexibility when working in crowded wireless environments. With an operating voltage range of 10.5 to 34 volts, the system integrates smoothly with a wide variety of professional camera rigs.
User Interface
If the exterior of the Hi-5 represents ARRI’s mastery of industrial design, the internal software reveals their understanding of modern digital workflows. The hand unit’s interface is built around a flexible touchscreen system that allows assistants to customize the layout according to their needs. The unit’s display is a bright color touchscreen positioned for easy viewing during operation. Even under harsh sunlight, the information remains clear and legible. The screen allows assistants to monitor focus distance, lens data, motor status, and radio connectivity without diverting attention from the shot for more than a moment. Navigating the menus feels straightforward and responsive. Focus marks, lens files, radio channels, and camera controls can all be accessed quickly without digging through complicated menus. For a focus puller, speed matters. Moments on set move quickly. Seconds saved on troubleshooting the camera can be the difference between making the day and losing the next job.
One of the most powerful aspects of the Hi-5 is its integration with lens metadata systems. Modern cinema lenses often transmit detailed information about focus distance, iris value, and focal length. ARRI’s Lens Data System, commonly known as LDS, was designed to capture and communicate this information throughout the camera ecosystem. The Hi-5 reads and displays this metadata directly, giving the assistant a clear picture of the lens’s current state. Compatibility with Cooke’s /i protocol further expands the range of supported lenses. Whether the production is using ARRI Signature Primes, Cooke S7s, or other modern cinema optics, the Hi-5 can interpret and display the relevant data. Accurate lens metadata allows VFX artists to replicate the exact optical characteristics of the shot in postproduction. Focus distance, focal length, and distortion profiles can all influence how digital elements are composited into the scene. Beyond lens control, the Hi-5 can also communicate with a variety of camera systems. While it integrates most seamlessly with ARRI cameras such as the Alexa Mini, Alexa Mini LF, and Alexa 35, it can also interface with other major platforms including the Sony Venice and various RED cameras through compatible control licenses. From the hand unit, a focus puller can trigger camera run and stop commands, monitor camera status, and in some cases adjust specific settings. This level of integration reduces the need for additional control devices and streamlines the overall workflow on set. Wireless communication remains the backbone of the system. The Hi-5 transmits commands to lens motors through a robust radio architecture designed to withstand the increasingly crowded RF environments of modern productions. Whether the camera is mounted on a handheld rig or flying hundreds of feet away on a crane, the focus puller maintains reliable control.
Adjustability
One of the defining strengths of the Hi-5 is its adaptability. No two film sets are the same, and ARRI designed the system to accommodate a wide variety of shooting conditions. A key feature is the use of interchangeable radio modules. Instead of locking the hand unit to a single frequency band, ARRI allows users to swap RF modules depending on regional regulations or interference conditions. Modules operating in different frequency ranges can be installed in seconds, ensuring reliable communication even in difficult environments.
Equally important are the Smart Focus Rings developed for the Hi-5 system. These rings attach to the focus knob and contain electronic contacts that allow the hand unit to recognize the scale automatically. For a focus puller, this dramatically simplifies the process of swapping lenses. Instead of manually aligning focus scales, the Hi-5 reads the ring and maps the lens data instantly. The physical feel of the focus knob can also be adjusted to match personal preference. Torque and resistance settings allow assistants to create a tactile response that mirrors the behavior of different lenses. This subtle customization helps maintain consistency when moving between different projects or lens sets.
Among the more subtle yet useful features is the unit’s haptic feedback system. The Hi-5 can vibrate when the focus approaches a programmed mark, giving the assistant a physical cue without requiring constant visual attention. This becomes particularly valuable when operating in situations where the focus puller must divide attention between the monitor, the actors, and the hand unit itself. These layers of adjustability transform the Hi-5 into a highly personal tool. Every assistant develops their own preferred configuration, shaping the device to suit their working style.
Ecosystem
While the Hi-5 is impressive as a standalone hand unit, its true strength emerges when viewed as part of ARRI’s broader Electronic Control System ecosystem. This network of devices and software creates a comprehensive platform for lens and camera control. At the camera side of the system are ARRI’s cforce motors, including the compact cforce mini and the more powerful cforce plus models. These motors attach directly to the lens gears and translate the wireless commands from the hand unit into precise mechanical movement. The motors communicate through ARRI’s LBUS protocol, allowing multiple devices to operate seamlessly on the same network. The RIA-1 receiver interface adapter acts as the central hub connecting the radio system to the camera and motors. It bridges wireless communication with wired motor control, enabling the Hi-5 to operate at considerable distances from the camera. Additional control devices expand the system’s versatility. The OCU-1 operator control unit allows camera operators to adjust iris or focus directly from the camera body while the focus puller maintains overall control from the Hi-5. This collaboration between operator and assistant can be invaluable in fast-moving shooting environments.
ARRI also offers a range of software licenses that unlock deeper integration with other technologies. Compatibility licenses enable communication with RED and Sony cameras, while specialized tools such as Cinefade allow for automated focus transitions that can simulate depth-of-field effects in camera. Integration with rangefinder systems like Focusbug brings real-time distance measurement into the workflow, assisting focus pullers in maintaining sharp images even under challenging conditions. The ECS Sync App further extends the ecosystem into the digital realm. Through this application, lens files and configuration settings can be managed, updated, and shared across devices. Firmware updates ensure that the system continues to evolve over time, adding new capabilities long after the hardware itself has been released. For the focus puller, this ecosystem transforms the Hi-5 from a simple control device into the central command center of the camera’s optical system. Every component from the motors to the metadata pipeline works together to support the delicate task of maintaining sharp focus on moving subjects.
Focus pulling is one of the most demanding crafts on a film set. It requires precision, intuition, and constant awareness of the actors, the camera, and the story unfolding within the frame. By supporting the focus puller with reliability, flexibility, and thoughtful design, the Hi-5 helps keep the creative momentum of the set moving forward. And when everything aligns – the actors hit their marks, the camera glides through space, and the image snaps perfectly into focus – the technology fades into the background, leaving only the magic of cinema.
The ARRI Hi-5 is available for rent at Cine Visuals. For inquiries or testing appointments email info@cinevisuals.com or call (323) 244-2552.
