New optical design:  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 f/2.8 zoom lenses such as the 24-70mm f/2.8 and 70-200mm f/2.8 zooms by Canon and Nikon to produce 17-50mm f/2.0 and 50-142mm f/2.0 high-speed zooms, respectively.  Similarly, high-speed fixed focal length lenses such as a 50mm f/1.2 will be transformed into a 35.5mm f/0.9 lens with excellent contrast and resolution from the center all the way to the edges of the image. (More information can be found in the press release here)

Key Features

Increase maximum aperture by 1 stop.

Increase MTF.

Makes lens 0.71x wider.

 Advanced 5-element/4-group optical design incorporating ultra-high index tanatalum-based optical glass by Caldwell Photographic in the USA (patent pending).

Electronic integration of aperture diaphragm, controlled by or from the camera body.

Partial autofocus support for late-model (post-2006) Canon-brand lenses.

Powered by camera body. No external power source required.

High performance 32-bit processor and efficient switched-mode power supply.

The tripod foot is detachable and compatible with Arca Swiss, Markins, Photo Clam ball heads.

Flocking material coating inside the inner hole to reduce the internal reflection.

EF lenses

Image stabilization (IS) lenses

Electronic manual focusing (e.g. EF 85/1.2L II and discontinued EF 50/1.0L)

EXIF (focal length, aperture, zoom range)

P, A, S, M exposure modes

Autofocus (see autofocus support section below)

Distance and zoom display on VG and FS series camcorders (see note 1)

Auto magnify (see note 1)

Contax N mount lenses modified to Canon EF by Conurus (see note 2)

Contax 645 NAM-1 adapter modified to Canon EF by Conurus (see note 2)

Sigma, Tamron and Tokina lenses in Canon EF mount (see note 3)

EF-S lenses

DX lenses

NEX-VG900 (see note 4)

Lens correction such as peripheral shading, CA and distortion

Focus confirmation "chip" (e.g. Dandelion)

M42 screw mount adapters (see note 6)

Stacking non-Metabones/non-Conurus mount adapters on top (see note 7 and list of lenses which require modification below.)

Certain telephoto lenses (see note 8)

Lens: Tamron SP 17-50mm F/2.8 XR Di II VC