The Metabones Speed Booster ULTRA has a magnification of 0.71x, and so it effectively reduces the crop factor of mirrorless cameras with DX-sized sensors, such as Sony E-mount and Fuji X-mount cameras, from 1.5x to 1.07x. It will fit the Sony A7 bodies but will have to be used in “APS-C Size Capture” to fully support the speed booster’s functions.
- Increase maximum aperture by 1 stop.
- Increase MTF.
- Makes lens 0.71x wider.