ARRI Electronic Control System

ARRI Electronic Control System

ARRI's Electronic Control System is a sophisticated toolset for remote camera and lens control. It includes the award-winning WCU-4 wireless 3-axis hand unit, which displays extensive lens data when used with ALEXA Plus and Studio cameras, as well as its smaller companion, the SXU-1 single-axis hand unit for controlling focus, iris or zoom. 

New tools being released in 2014 give the Electronic Control System complete operational autonomy, allowing the WCU-4, SXU-1 and other system elements to be used with all kinds of lenses and cameras, including the new ARRI AMIRA but also any third-party camera on the market. All system components are built to withstand hard, prolonged use on set, and are backed by ARRI's worldwide network of official service centers.


  • 3-axis remote control of focus, iris and zoom on any camera 
  • LDS Lens Data Archive for accurate lens data with any lens 
  • Long-range radio system for reliable connectivity 
  • Internal and external timecode for lens data synchronization 
  • Serial interfaces to peripheral equipment 
  • Focus tracking with ultrasonic measurement devices 
  • Large display for setup and vital status information 
  • SD card slot for lens data storage and file transfer 
  • Ethernet interface for IT integration 
  • Optional interfaces to Canon and Fujifilm focus and zoom demands



The new Universal Motor Controller UMC-4 is an advanced 3-axis motor controller that offers functions previously only available with ALEXA Plus and Studio cameras. By incorporating ARRI's LDS Lens Data Archive, the UMC-4 goes beyond mere camera and lens control to offer the added value of lens data that is useful both on set and in post.


Lens data provides the current setting for focus, iris and zoom. This information enables lens mapping to pre-marked focus rings and depth-of-field display on the WCU-4 wireless hand unit. It also enables the UMC-4 to do focus tracking -- setting the focus motor to continuously follow a subject in the frame by using an ultrasonic measuring device. For VFX tasks in post, the UMC-4 records frame-accurate lens data, with timecode, that helps match the virtual lens to the recorded image.


The UMC-4 includes multiple serial interfaces (RS232/422/485) that can be configured for peripheral equipment such as ARRI's UDM-1 distance measurer, or that can stream real-time lens data on set. Optional connector modules directly interface with focus and zoom demands from Fujifilm and Canon. An Ethernet connector integrates the UMC-4 with standard IT equipment, allowing convenient lens table programing and Ethernet-based system control. The intuitive user interface makes the UMC-4 easy to use, while its high-quality outdoor antenna offers improved durability and reliable radio connectivity. Software updates can be easily performed via SD card, ensuring a future-proof system that can adapt as new functions evolve.


ARRI is introducing two small and lightweight motor controllers that offer an alternative to the UMC-4, providing basic lens control functionality for setups where size and weight matter.

The ENG Motor Controller EMC-1 was specifically developed for use with ENG-type lenses such as the Fujinon Cabrio Zooms. The EMC-1 controls the integrated focus, iris, and zoom motors of such ENG lenses and provides lens data for display on the WCU-4 hand unit.

The Single Motor Controller SMC-1 is a compact 1-axis motor controller designed for weight and size-critical setups such as Steadicam or camera drones. It drives a single CLM motor and is the perfect counterpart for the SXU-1 single-axis hand unit.


ARRI's Lens Data System (LDS) comprises a range of products generating highly accurate lens data for use on set and in postproduction. Lens data generation has two basic requirements: encoders that determine the current setting of a lens axis, and a lens table that interprets these raw encoder values. ARRI offers two configurations:

1.) LDS lens and LDS-mount camera: each LDS lens can detect the position of its lens rings and store its own lens table. When mounted to an LDS-compatible camera (AMIRA and most ALEXAs), the data is transmitted to the camera, which calculates the actual lens value internally. This 'plug-and-play' system requires no additional setup.

2.) External lens encoders and the Lens Data Archive: As well as allowing remote control of the lens, ARRI's controlled lens motors deliver raw data about the position of the lens rings to either a UMC-4 or an ALEXA Plus module. Both of these devices include the LDS Lens Data Archive, which provides the lens tables and enables them to calculate the lens data, making the advantages of ARRI's Lens Data System available to any lens.