The new ARRI 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...