Wireless Compact Unit WCU‑4

It's all in your hands

WCU-4 klein rechts (2)
Advanced Lens and Camera Control

The Wireless Compact Unit WCU‑4 is a lightweight, ergonomic hand unit offering up to 3-axis lens control. Rugged and splash-proof, it features an easy-to-read lens data display, lens mapping to pre-marked focus rings and focus tracking, for example of the slate at the beginning of a shot.


Best overall production value 

  • Ergonomic 3-axis lens control
  • ARRI camera remote control
  • Lens programming interface
  • Backlit focus knob with adjustable friction
  • Easy-to-read lens data display
  • Lens mapping to pre-marked focus rings
  • Support of the OCU‑1 or Master Grips override function

Useful features

  • Distance measurement readout
  • Focus tracking function
  • Remote REC and tally
  • Personalized settings
  • Playback function
  • Vibrating markers

Useful Features

  • Camera remote control functionality for ALEXA Mini LF, ALEXA Mini, AMIRA when used with the UMC-4 motor controller or cforce mini RF, ALEXA Plus, XT Plus, Studio, XT Studio, SXTW Plus and 65.


Gentefied (1)


Homeland (1)




ford v ferrari

Ford v Ferrari

and we go green

And we go green

Hand of God (1)

Hand of God



above suspicion

Above Suspicion

angel of mine

Angel of mine

True Detective

True Detective Season 3

7 days out (1)

7 days out

ant-man and wasp

The ant-man and the wasp

black panther

Black Panther

kleine hexe

Die kleine Hexe





osiris child

The Osiris Child



the exorcist

The Exorcist


Most of the time I actually work with the ARRI WCU‑4 and the 0.5 m pre-marked focus ring, as it is very reliable. The WCU‑4 is the most stable hand unit and the triangle function on the focus scale when I am using a distance measurement device was super important - especially with dolly push-ins and when we had an aperture of T0.8.

1st AC Emanuel Köll (Known for: Die Toten vom Bodensee – Der Seelenkreis, Love Machine, Sargnagel, Post Mortem, Wanda music videos and many more)

I’ve been using the ARRI WCU‑4 since it first became available. On this year’s Super Bowl halftime show with “The Weeknd,” we used ALEXA Minis and RF motors for focus, to communicate with the WCU‑4. The WCU‑4s performed perfectly, with no interference from outside sources in the stadium. While camera settings were being controlled remotely from the truck, we retained full control of focus. We had no issues with the gear and the live show was a flawless success.

Focus puller Joseph K. “Tampa Joe” Boylan

I love working with the WCU‑4 because the display with the lens data, the pre-marked focus rings and the green triangle from the UDM are a perfect combination to keep the shot in focus. 

1st AC Alois Kozar (Known for: Rubikon, Ugly, 7500 and many more)

The WCU4 is the most robust, complete and customisable solution I have ever used for wireless focus. It has features that make it far superior to the competition. From real-time DoF on the large backlit screen, to vibrating focus marks, customisable buttons and much more. I love being able to change camera settings right from the handset when the camera is mounted on a crane or arm. 

1st AC Ambar B Capoor (Known for: Lovelace, The Grand Tour, Transparent, Con Man, Rosewood and many more) 

Focus pulling is the art of remembering the past and knowing the future.
The WCU‑4 never let me down.

1st AC Karl Keil, BVK (Known for: Homeland, Babylon Berlin, TV-Series and many more)

The WCU‑4 is very light, comfortable in my hand and super ergonomically when it comes to mounting and also for the run and gun life. Camera control at your fingertips has been a fantastic tool for steadicam and crane stuff. 

1st AC Brian Aichlmayr (Known for: Playing God, Dropa, Sanitatum, Osprey, Commercials for Brands such as Walmart, Nike, Intel, Reebok, Facebook, Adidas and many more)

For me the WCU‑4 was the obvious choice of lens control - most of my jobs are on ARRI cameras, and so being able to control a lot of the settings from my handset is fantastic. I also really like the lens mapping with the easy to see the UDM readout/arrow.

1st AC Julia Green (Known for: Solo: A Star Wars Story, Black Mirror: Bandersnatch, Mary Queen of Scot, The Breaker Upperers, Random Acts and many more)

The biggest advantage of the WCU‑4 is that it combines so many features into one compact device. Keeping so much control in your hand in the form of a device makes the daily workflow much easier and helps us to master any new challenges on the job.

1st AC Sasha El Gendi (Known for: Unheimlich perfekte Freunde, Die Kleine Hexe, Smaragdgrün, Heidi, Point Break, Colonia Dignidad and many more)

The dependability and versatility of the WCU4 allows me to achieve everything that has been asked of me no matter what project I have been involved in. 

1st AC Philip A.T. Smith (Known for: Dune, Wonder Woman 1984, The King, John Wick: Chaper 3 – Parabellum, Solo: A Star Wars Story, The Great Wall and many more)

The WCU‑4 system, with all its wireless possibilities to control the focus, iris, zoom and the camera settings combined in one unit, allows us on set the most of flexibility and is on top also easy to handle. The perfect all-round tool for today’s 1.ACs.

1st AC Oliver Schill (Known for: Haven: Above Sky, Bliss, Hell, Meiberger – Im Kopf des Täters, Jugend ohne Gott, Nackt. Das Netz vergisst nie and many more)

What I like at the WCU‑4 most is its large digital display. In combination with lens data it is very easy to follow the signal of a range finder system. And it is very easy to spread the scale of the lens in Situations I have not much dept of field. 

1st AC Boris Treffert (Known for:  Die Spezialistn – im Namen der Opfer, Jonas Waldek, Keine zweite Chance, Block B – Unter Arrest, DieTrixxer, Headhunter: The Assessment Weekend and many more)

The WCU4 fits easily in your hand and weights barely anything. Its ergonomic design just hasn’t been matched in the newer models of any competing manufacture. It’s also become the standard as newer handsets are always trying to recreate the brilliance of the WCU4’s layout.

1st AC (Focus Puller) Ian Barbella (Known for: Gentefied, Moxie, The Exorcist, Teachers, I Am the Night, Corporate, Wakefied and many more)

The WCU‑4 is a compact and very versatile system. I like the fact that all three axis (Focus, Iris and Zoom) can be operated from only one device and that I can occupy each unit individually. The WCU guarantees a fast and precise work on the set.

1st AC Manuel Steer (Known for: Papa auf Wolke 7, Flucht durchs Höllental, Die Rosenheim Cops, Das Ende der Wahrheit, Tatort and many more)

Using a WCU‑4 when shooting on an Arri camera always makes a lot of sense for the additional camera control it gives, however even when using other manufacturers cameras it is still my go to choice. 

1st AC Matt Choules (Known for: Britannia, Dark Encounter, And We Go Green, The Revenger: An Unromantic Comedy, Berlin Station, Solis and many more)

The WCU‑4 is a precise tool for focus pulling, allowing me to easily retain control over the most used settings of the camera. Alongside of that, I find the customizability of its settings to suit my needs and the integration of distance measurements very useful. 

1st AC Aurel Wunderer, BVK (Known for: Guns Akimbo, die kleine Hexe, Euphoria, The Putin Interview, Buddenbrooks, Nirgendwo in Afrika, Die Manns – Ein Jahrhundertroman and many more)

The reason I work with WCU‑4 is because it's fast, precise, reliable, smart and easy to work with.

1st AC Tamás Jánossa (Known for: SAS: Red Notice, The Martian, Tyrant, The Selection, Mars, Genius, Lords of Chaos, Maigret in Montmartre and many more)

The WCU‑4 gives me full control of the camera which is incredibly useful when you are working quickly. Specially, on gimbals and on steadicam where you can’t always easily get access to the camera being able to adjust the NDs from the WCU‑4 or playback a clip for the director becomes a massive advantage.

1st AC James Hills (Known for: Greater Things, Bloody Cuts, Blackbird and many more)


OCU‑1 – Cine lenses

Override Function available


WCU‑4 or SXU-1 + cforce mini RF + cforce mini/plus motors + AMIRA

WCU‑4 or SXU-1 + EMC-1 + Servo Zoom lens

WCU‑4 or SXU-1 + UMC-4 + CLM motors

WCU‑4 or SXU-1 + AMC-1 + cforce mini/plus motor

WCU‑4 or SXU-1 + SMC-1 + CLM motor

WCU‑4 or SXU-1 + UMC-4 + cforce mini/plus

WCU‑4 or SXU-1 + cforce mini RF + cforce mini/plus motors

WCU-4 Dust Klein


1 - High-performance radio system for reliable connectivity 

2 - Lens mapping to backlit, pre-marked focus rings

3 - Fluid knob with adjustable friction for precise focus pulls

4 - Full control with lens data display and distance measure readout

5 - Ergonomic design for comfortable prolonged usage


  • Yes. You can use the WCU‑4 with any camera, using the Universal Motor Controller UMC-4, the cforce mini RF or the Mini Motor Controllers AMC-1, SMC-1 and EMC-1.

  • You can control up to three motors for focus, iris, and zoom. The ALEXA Remote License Key activates remote camera setup capabilities via WCU‑4 for ALEXA Plus, ALEXA Plus 4:3, ALEXA XT Plus, ALEXA Studio, ALEXA XT Studio, ALEXA SXT, ALEXA SXT W , ALEXA 65 and ALEXA Mini/Mini LF cameras, as well as for AMIRA if combined with the Universal Motor Controller UMC-4 or the cforce mini RF lens motor.

    This includes the following parameters:

    • Full Playback Control (ALEXA Mini/Mini LF)
    • Sensor Frame Rate
    • Shutter Angle
    • Exposure Index
    • White Balance
    • ND Filter (ALEXA Studio and ALEXA Mini/Mini LF/AMIRA)
    • Peaking on Monitor Output (on/off)
    • Surround View on Monitor Output (on/off)
    • False Color on Monitor Output (on/off)
    • Status Info on Monitor Output (on/off)
    • Frame Lines on Monitor Output (on/off)
    • User Buttons
  • There are many different lenses on the market and we do not have an individual pre-marked ring for all of them. We do have five pre-marked rings with metric scale and five rings with imperial scale. These rings can be mapped to any given lens by using the Lens Data Archive (LDA).

  • There are various ways to make good use of pre-marked rings. You can choose the ring marked with a close focus or minimum object distance (MOD) that is nearest to – but less than – the MOD of your lens. For example, if your lens MOD is 16”, you would choose the 14” focus ring. Or you simply select the ring with the focus scale spread that matches your scene best.

  • Lens data is transmitted to the WCU‑4 from the camera device where it is generated  (ALEXA Plus, ALEXA Plus 4:3, ALEXA XT Plus, ALEXA Studio, ALEXA XT Studio, ALEXA SXT, ALEXA SXT W , ALEXA 65 and ALEXA Mini/Mini LF cameras, Universal Motor Controller UMC-4 or the cforce mini RF lens motor).

  • The Lens Data Archive is an archive that contains lens tables. Those lens tables set the raw motor encoder values in correlation to the actual lens scales. Once you choose the right lens table from the Lens Data Archive and calibrate your lens motors, you get the same type of lens data as an LDS lens would deliver. You can create your own lens tables for any given lens with the WCU‑4, save it on SD card and transfer it to the ALEXA Mini/Mini LF, the Universal Motor Controller UMC-4 and the cforce mini RF wirelessly.

  • Lens data is generated on the camera side and displayed on the WCU‑4. The data is generated in one of two ways:

    1. From LDS lenses, via the internal lens encoders

    2. From the Lens Data Archive (LDA), via the motor encoders

ARRI Journey - ARRI Controller - Marsh-24_lowres
Robust and solid
ARRI WCU-4 Premarked Rings meter

Recommended Products

Related Products

Tech Tips & Tech Talks