Sharper corners, less distortion, reduced vignetting

New optical design: advanced 5-element/4-group optical design with ultra-high refractive, tantalum-based optical glass to achieve exceptional optical performance with improved corner sharpness, less 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, reducing 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 effectively utilizes exotic materials at the very edge of glass manufacturing technology, resulting in excellent correction for use with nearly all full-frame DSLR lenses, regardless of exit pupil distance. Thus, the Speed Booster ULTRA works exceptionally well with professional f/2.8 zoom lenses like Canon and Nikon's 24-70mm f/2.8 and 70-200mm f/2.8, creating 17-50mm f/2.0 and 50-142mm f/2.0 high-speed zooms. Similarly, high-speed prime lenses such as a 50mm f/1.2 are transformed into a 35.5mm f/0.9 lens with outstanding contrast and resolution from the center to the edges of the image.