The EF 3 Mounting Adapter improves upon the previous model in several ways.
Despite having a delay in shipping its anticipated MAVO Edge 8K cinema camera (now expected by February), Kinefinity has released a new EF mounting adapter for its MAVO LF/6K and TERRA cameras.
The EF 3 Mounting Adapter is based on the EF Mounting Adapter II but literally adds a new twist. When using the EF Mounting Adapter II, you wouldn't rotate the EF lens as you would on a traditional DSLR or mirrorless camera to secure it. Instead, you would hold the lens in place while rotating a locking ring to mount the lens to the camera. This is similar to mounting PL lenses.
The EF 3 is redesigned to simplify the process with a bayonet style mount. Users can now mount a lens as they normally would on a Canon camera by lining up the red dots and then rotating the lens clockwise. The EF 3 has an additional active lock to fully secure the lens. This is a nice improvement from Kinefinity as it adds confidence when lining up the communication pins between the lens and mount.
As the video above shows, what's unique about Kinefinity cameras is their KineMOUNT, which allows you to interchange the mount based on the lens.
Instead of the MAVO LF/6K or TERRA having a dedicated mount, they use an "open source" approach where you can easily swap out the mount yourself. They have options for PL, ARRI LPL, Canon EF, Sony E, and Nikon F.
Kinefinity also has its EF Mounting Adapter with e-ND filters and the EF Mounting Adapter II w/ KineEnhancer that acts as an expander. No word on if or when the EF 3 will be incorporated into those options. Most likely it will happen down the road.
You can find more info about the EF 3 Mounting Adapter here.