September 15, 2021


Software Update Package LF SUP 4.2 provides a critical bug fix for an error that prevents the camera from booting correctly. With ALEXA LF SUP 4.1 we were able to remove the most frequent occurrence of this issue and with ALEXA LF SUP 4.2 we were able to remove all occurrences of this issue by eradicating the root cause.

We strongly recommend updating all ALEXA LF cameras that currently have LF SUP 4.0 or LF SUP 4.1 software.  Cameras with LF SUP 3.0 or earlier are not affected.

LF SUP 4.2 requires LF SUP 3.0 Software & Hardware Upgrade

LF SUP 4.2 should only be installed on ALEXA LF cameras that have previously undergone the "ALEXA LF 3.0 Software & Hardware Upgrade", which can be performed free-of-charge by ARRI service. The ALEXA LF 3.0 upgrade includes the upgrade of an electronics board (ACDA3 gets exchanged for ACDA4), and LF SUP 4.0, 4.1 and 4.2 require the ACDA4 board. LF SUP 4.2 will not run on ALEXA LF cameras with the older ACDA3 board installed (any camera running LF SUP 2.0 or LF SUP 2.1).

Upgrade Paths

  • If your ALEXA LF has LF SUP 2.0 or 2.1: contact ARRI Service to schedule your free upgrade to "ALEXA LF 3.0 Software and Hardware". ARRI service will then also install LF SUP 4.2. More information about the "ALEXA LF 3.0 Software and Hardware Upgrade" can be found below.
  • If your ALEXA LF has LF SUP 3.0, 4.0 or 4.1: Download LF SUP 4.2 and install.


Once LF SUP 4.2 is installed, it is possible to revert back to LF SUP 4.0 and LF SUP 4.1, but not to LF SUP 3.0 or older. However, due to the nature of the issue that 4.2 avoids, it is not recommended to downgrade to LF SUP 4.0 or LF SUP 4.1.


Software Update Package LF SUP 3.0 for ALEXA LF contains:

New Features Overview

A more detailed description of each feature is given in the section 'New Features and Changes'.

• Support for ALEXA Electronic Viewfinder EVF-2

• Support for SxS PRO+ 256 GB cards

• Support for battery adapters BAB-HG & BAB-HV

• New features

  • Six ZOOM positions for EVF-1/2 & MON OUT
  • Simplified global anamorphic de-squeeze
  • Monitor Identification

Please note that LF SUP 3.0 and later will not run without a new electronic board (ACDA4) in the camera. Newly manufactured cameras will have the new board and the latest SUP installed. Existing cameras running LF SUP 2.0 or LF SUP 2.1 can be updated from ACDA3 to ACDA4 and from LF SUP 2.0/2.1 to the latest SUP by all ARRI Service Centers, free of charge. This is also why LF SUP 3.0 is not available for download on the ARRI website. Please contact ARRI Service to schedule an appointment.