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 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.

Features & Benefit

• Increase maximum aperture by 1¹/₃ stop
• Increase MTF
• Makes lens 0.64x wider
• Patented 6-element/4-group optical design by Caldwell Photographic in the USA
• Supports 4k video mode with DX lenses.

Limitations

• Supports only Panasonic GH4, GH3, G3, G5, G6, G7, G10, GF3, GF5, GF6, GX1, GX8, Olympus E-PL7, Blackmagic Cinema Camera with Micro Four Thirds mount**, Blackmagic Pocket Cinema Camera*** (Please refer to the link below for further information)
• EF-S lenses require modification to fit (but third party DX lenses can be used without modification)
• EF-S and third party DX lenses may not cover the full Micro Four Thirds sensor in still photo and FHD video modes (but will cover 4k video mode)

For more information on compatibility, please refer to this weblink: