Today Arri announced that they will offer a new software upgrade for the AMIRA, which will allow it to record ProRes Ultra HD files (at a resolution of 3840x2160). The upgrade is expected to be available for purchase at the online Arri License Shop by the end of 2014.
The new Arri ALEXA HD camera is designed for economical and efficient HD video workflow. It shares the same sensor, color processing, controls, and menus, as well as accessories and software license options as the rest of the ALEXA line.