Featuring an advanced 5-element/4-group optical design incorporating ultra-high index tanatalum-based optical glass to achieve extraordinary optical performance with improved corner sharpness, distortion and reduced vignetting.
Like the revolutionary original Metabones Speed Booster announced in January 2013, the 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. However, the new ULTRA design makes very effective use of exotic materials at the furthest limit of glassmaking technology, and as a result is well corrected for use with virtually all fullframe SLR lenses regardless of exit pupil distance. Thus, the Speed Booster ULTRA performs extremely well with professional-grade f2.8 zoom lenses such as the 24-70mm f2.8 and 70-200mm f2.8 zooms by Canon and Nikon to produce 17-50mm f2.0 and 50-142mm f2.0 high-speed zooms, respectively. Similarly, high-speed fixed focal length lenses such as a 50mm f1.2 will be transformed into a 35.5mm f0.9 lens with excellent contrast and resolution from the centre all the way to the edges of the image.
The Mark V Speed Boosters are equipped with a rubber gasket to protect the E-mount connection from dust and moisture. To promote ease-of-use, an LED indicates the adapter's operation mode, optical image stabilization operation and communication status. A dedicated switch controls in-body image stabilization (IBIS) on Sony cameras equipped with SteadyShot INSIDE.