ARRI EF Mount (LBUS)
Expand your lens horizon
Expand your lens horizon
The ARRI 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 ARRI 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 ARRI 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 ARRI 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)
No, the new ARRI 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).
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 ARRI 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.