Metabones EF-MFT T Speedbooster XL 0.64x Adapter

This adapter allows a full frame Canon EF mount lens to be used with a MFT camera. By focusing the image onto the smaller sensor size you effectively gain one and 1/3 stops of aperture.

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 11/3 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.

Magnification: 0.64x
Crop Factor for Full Micro Four Thirds format: 1.28x
Crop Factor with GH4 in Cinema 4k (4096 x 2160) Video Mode: 1.5x
Maximum Output Aperture: f/0.80 (with f/1.2 lens attached)
Rectilinear Distortion: 0.8%
Lens Elements/Groups: 6/4
Length Reduction: 6.2 mm
Camera Mount: Micro Four Thirds
Image Format: 17.3 mm x 13.0 mm (full Micro Four Thirds format)