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Use any EF mount lens on ALEXA Mini LF or ALEXA Mini

Compatible with cine-style and still photo EF mount lenses


The EF Mount (LBUS) allows the ALEXA Mini LF or ALEXA Mini to accept lenses with an EF mount and it also provides an LBUS connector.

In order to extend the benefits of using EF mount lenses to large-format motion picture productions, ARRI has redesigned its EF mount with a wider light baffle, allowing it to cover the large-format sensor of the ALEXA Mini LF, as well as the Super 35 sensor of the ALEXA Mini.

The use of cine-style EF mount lenses on motion picture cameras has been a popular way to make more affordable optics available to budget-conscious productions. Their mechanical focus rings with physical end stops and industry-standard gears allow the use of external lens motors and precise remote control through ARRI ECS hand units like the wireless WCU-4 and SXU-1 and the wired Operator Control Unit OCU-1 and Master Grips. Setup of external lens motors is fast and clean with the LBUS connector on the lens mount, which frees up the EXT connector on the Mini LF and Mini. With the use of the ARRI Lens Data Archive, metadata from the external lens motors will be displayed as well as recorded. 

Additionally, the EF Mount (LBUS) allows filmmakers to utilize the wide variety of still photo EF mount lenses for insert shots, including vintage lenses, extreme wide-angle lenses, fisheye lenses, tilt-shift lenses, extreme telephoto lenses, macro lenses and other specialist EF mount lenses. For specialty shots, the EF mount (LBUS) even powers the image stabilization built into some telephoto EF mount lenses. Since most still photo EF mount lenses have internal iris motors, those can be set by the camera and ARRI ECS hand units.  

Built to ARRI’s exceptionally high standards of durability and reliability, the EF Mount (LBUS) is suitable for hard-wearing use on professional film sets. 


Use EF mount lenses on ALEXA Mini LF or ALEXA Mini

- Wide light baffle for with large-format and Super 35 sensors

- Use affordable cine-style EF mount lenses 

- Use the wide variety of still photo EF mount lenses 

- Use image stabilization in EF mount telephoto lenses

- Locking ring for secure mounting and stable flange focal distance

Control cine-style EF mount lenses with ARRI ECS hand units

- LBUS connector allows fast and clean setup of external ARRI cforce lens motors

- LBUS connector frees up EXT connector on Mini LF and Mini

- Wireless lens control with WCU-4 or SXU-1

- Wired lens control with OCU-1 or Master Grips

- Display and record lens metadata with Lens Data Archive (LDA)

Set iris of still photo EF mount lenses

- On most lenses with 1/4 steps

- Set from camera

- Set from ARRI ECS hand units

Camera Compatibility

The EF Mount (LBUS) is compatible with the ALEXA Mini LF and ALEXA Mini. The EF Mount (LBUS) does not physically fit the AMIRA, nor does the AMIRA support the mounts’ LBUS connector. This is why the old, slightly less expensive EF Lens Mount remains available.

Note: LBUS accessories can still be used with AMIRA by using an EXT to LBUS adapter cable to connect the AMIRA to the LBUS accessory. 

The EF Mount (LBUS) does not require a specific camera Software Update Package (SUP).


  • The new EF Mount (LBUS) (K2.0019965) was designed for Super 35 and large format. It is mechanically compatible with the ALEXA Mini and ALEXA Mini LF. Due to the wide light baffle, large format EF Mount lenses will not vignette. The LBUS connector allows connecting any LBUS device and frees up the EXT connector on the camera.

    The old EF Lens Mount (K2.0001103) was designed for Super 35 recording resolutions. It is mechanically compatible with the ALEXA Mini, AMIRA and ALEXA Mini LF, but vignetting may be visible on the ALEXA Mini LF when using large format EF Mount lenses. Please note, that the amount of vignetting is based on the optical lens design, the focal length and the aperture, and therefore, we cannot provide information as to which lens will vignette how much. If you want to find out how much a given lens vignettes, we recommend shooting a test.

    The image below shows the new EF Mount (LBUS) on the left and the old EF Lens Mount on the right side.

  • No, the new EF Mount (LBUS) is mechanically not compatible with the AMIRA and the AMIRA does not support the mounts’ LBUS connector. If you want to use EF Mount lenses on an AMIRA, use the EF Lens Mount (K2.0001103).

  • The position of the LBUS connector on the EF Mount (LBUS) was chosen to allow compatibility not only with current, but also with future cameras. 

  • Since cine cameras are exposed to greater stresses than stills cameras, it is important to safely lock the lens to the camera. This also ensures a stable flange focal depth by pushing the lens securely against the lens mount flange surface. 

  • Still photo EF mount lenses with internal lens motors will automatically calibrate their focus and iris motors to their memorized virtual end stops when you connect them to the EF Mount (LBUS), as long as the camera is powered on, and on the lens  the Auto-Focus (AF) switch is set to ON or the MF/AF switch is set to AF. There is no manual calibration possible, or necessary.  

  • Since the iris of most still photo EF mount lenses can only be set in steps of 1/4 stops, we recommend against a live iris pull during the shot with still photo EF mount lenses.  

  • It is not possible to calibrate external lens motors on the focus ring of an EF mount still photo lens, as these lenses have a freely rotating focus ring without end stops, and the lens motor expects an end stop for calibration.  

  • Yes. To use the cforce mini RF motor, which is our fastest and most responsive motor, in the most effective way, switch the motor to “client” mode and connect it with an LBUS cable to the EF Mount (LBUS). The motor will use the camera's radio and will communicate lens ring position metadata to the camera. 

  • Yes and no. 

    If you use cine-style EF mount lenses, that have a mechanical focus ring with end stops, and if you use an external lens motor to drive the focus ring, yes, you can. And you can use the ARRI ECS hand units, like WCU-4 or SXU-1 as wireless focus controllers or the OCU-1 or Master Grips as wired focus controllers. 

    We recommend against professional focus pulling with still photo EF mount lenses with internal focus motors. While rudimentary control of the focus motor of most still photo EF mount lenses is possible with ARRI ECS hand units to set a focus distance, actual focus pulling does not work so well. The accuracy and repeatability of focus marks as well as the smoothness of the focus lens ring motion do not match what is possible with external lens motors and vary greatly from lens to lens. 

    So: focus pulling with cine-style EF mount lenses and external lens motors is definitely possible, but focus pulling with still photo EF mount lenses using the internal focus motors is not recommended.

  • ALEXA Mini LF机身和镜头卡口之间的接口技术跟ALEXA Mini以及AMIRA是一样的,所以从物理方式来说,ALEXA Mini或AMIRA能用的镜头卡口也能用在ALEXA Mini LF上。但是,有些镜头卡口不应该用在ALEXA Mini LF上,因为它们带来明显的暗角。目前,我们建议在ALEXA Mini LF上使用以下镜头卡口:

    • ARRI LPL镜头卡口(如下图所示安装到ALEXA Mini LF上)是所有LPL镜头最理想的卡口方案,搭配PL-LPL转接环(如下图所示,机身前方)还支持所有的S35或全画幅PL卡口镜头。LPL卡口支持LDS-2和库克/i镜头数据系统,PL-LPL转接环支持LDS-1和库克/i镜头数据技术。
    • 徕卡M 0.8镜头使用的LEITZ M卡口支持ALEXA Mini LF,该卡口由徕卡直接提供。更多信息请点击这里
    • 潘纳维申为ALEXA Mini LF开发了PV和PV70卡口。


    • ALEXA Mini的钛合金PL LDS LBUS卡口(K2.0003216)是针对S35画幅设计的,只适合S35机身。由于LPL卡口组合PL-LPL转接环比单纯使用Mini PL卡口暗角更少,我们不建议在ALEXA Mini LF上使用Mini PL卡口。
    • EF镜头卡口(K2.0001103)是针对S35画幅设计的,它可以用在ALEXA Mini LF上,但搭配全画幅镜头可能会有暗角。未来将推出一种带LBUS接口、支持S35和大画幅格式、遮光板更宽的EF卡口(LBUS)

Tech Talk Live: The new ARRI EF Mount (LBUS)

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