Freefly produces high-speed cameras to capture slow-motion footage, and has been known for its E-mount cameras. They have just announced the new Ember 2.5K camera, at NAB 2024, with a Canon EF mount which shoots at up to 2,900fps.
By 'active', Freefly means that the mount has electronics that allow the camera to talk with and control the Canon EF mount electronics through the camera body (or the camera's remote controls).
