Another solution is coming: apertus° launch a crowdfunding campaign for an open source & free video camera
apertus° has launched a crowdfunding campaign today for the AXIOM Beta, the first free & open digital 4K cinema camera.
Link is here: https://www.indiegogo.com/projects/axiom-beta-the-first-open-digital-cinema-camera/x/8611015
And you will find more informations on the web site: https://www.apertus.org/
No more problem then on upgrading or hacking himself the camera, as it is open definitively and all inside details are published and accessible for free!