Panasonic S1/H

https://www.reddit.com/r/blackmagicdesign/comments/174muyl/internally_its_a_completely_different_camera/

https://forum.blackmagicdesign.com/viewtopic.php?f=2&t=188113&start=300

Sensor: IMX410 (unconfirmed)

Panasonic S5II/X

https://www.reddit.com/r/blackmagicdesign/comments/174muyl/internally_its_a_completely_different_camera/

https://forum.blackmagicdesign.com/viewtopic.php?f=2&t=188113&start=300

Sensor: IMX410 (same gain circuit as Sony FX9) (unconfirmed)