So Blackmagic surprised everyone and announced the new Blackmagic Pocket Cinema 6K camera, which has a Super 35mm Sensor and an EOS lens mount. The sensor is an impressive 6144×3456 sensor, and the Super 35mm means aps-c size which means a 1.6x crop factor vs the 2x crop of the 4K mft version. And it is $2495 vs $1295, but doesn’t need a Speed Booster, which would have fixed the crop factor, and increased the lens speed, but also added more glass between the sensor and lens.
Now the camera will eat more battery than the already battery eating 4k (That it turns out is why they made the battery grip). And the new camera only shoots ProRes in 4k and UHD, saving BRAW for 6k. And the current manual only lists 4k speeds for drives and Cfast cards.
For someone with EF lenses this is a dream camera, if only I could afford it right now!