Metabones MB_SPEF-M43-BT3, Canon EF, T mount, Black, Silver

A Micro-4/3 mount Speed Booster adapter designed exclusively for the Panasonic GH4 and other selected Micro Four Thirds cameras, 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 record for Micro Four Thirds format.

The 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 11/3 stops, with a maximum output aperture of f/0.80 when an f/1.2 lens is used. For example, a 50 mm f/1.2 becomes a 32 mm f/0.80, which is a faster aperture available for full size Micro Four Thirds format.