Metabones Nikon SpeedBooster for the Blackmagic Pocket Cinema Camera.
Note that this new 0.58x Speed Boosters will only attach to BMPCC equipped with a Micro-4/3 mount. They cannot be attached to standard Micro 4/3 cameras.
The new 0.58x Speed Booster reduces the crop factor of the BMPCC from 2.88x to 1.75x, and produces the largest aperture optics currently available, with a maximum output aperture of f/0.74. For example, a 50mm f/1.2 now becomes a 87.50mm f/0.74. An increase of 1 stop and 2/3rds.