A new Micro-4/3 mount Speed Booster adapter designed exclusively for the Panasonic GH4 and other selected Micro Four Thirds cameras (refer to the below camera compatbility table), with a magnification of 0.64x.  The Speed Booster XL 0.64x uses an advanced 6-element optical design to achieve extraordinary optical performance at apertures up to an incredible f/0.80, a new record for Micro Four Thirds format. 

The new Speed Booster XL 0.64x reduces the full-frame crop factor of the Panasonic GH4 from 2.0x to 1.28x, thus effectively transforming these cameras into APS-H format.  When the GH4 is used in Cinema 4k video mode the horizontal full frame crop factor is reduced from 2.34x to 1.50x, thus effectively transforming the GH4 into a super-35 format 4k cine camera.  In addition, the speed of any attached lens is increased by 1 1/3 stops, with a maximum output aperture of f/0.80 when an f/1.2 lens is used.  For example, a 50mm f/1.2 becomes a 32mm f/0.80, which is the fastest aperture available for full size Micro Four Thirds format.

Although the Speed Booster XL 0.64x has extra clearance compared to the 0.64x BMCC Speed Booster, there are still a number of Micro Four Thirds cameras that are not supported due to mechanical clearance issues.  This is summarized in the table below, which is color-coded so that Green means the camera is supported and Red means the camera is not supported. 

Note that many of the Red-coded cameras actually do function, but there is a minor interference with the protective shutter cover.  Although slight contact with the shutter cover appears to have no effect on the functioning or cosmetics of either the camera or the Speed Booster we cannot support these combinations due to possible risk of damage.

*Not yet tested