Metabones Canon EF to MFT Speed Booster 0.71x

Overview
The Metabones Speed Booster ULTRA for Canon EF lenses to Micro Four Thirds mount cameras has several impressive features. Firstly, it can increase the maximum aperture of a lens by 1 stop, resulting in improved performance in low light situations. It also has the ability to increase the MTF (modulation transfer function) of a lens, which measures its ability to reproduce fine details. Additionally, the Speed Booster ULTRA makes a lens 0.71x wider, effectively reducing the crop factor of mirrorless cameras with DX-sized sensors.

This advanced adapter also boasts a 5-element/4-group optical design, incorporating ultra-high index tanatalum-based optical glass, developed by Caldwell Photographic in the USA. This design, which is patent pending, achieves extraordinary optical performance with improved corner sharpness, distortion, and reduced vignetting. The Speed Booster ULTRA is powered by the camera body and does not require an external power source. It also has a detachable tripod foot, making it compatible with Arca Swiss, Markins, and Photo Clam ball heads. However, it should be noted that some manual focus lenses may require modification before they can be safely used with the Speed Booster ULTRA.

Summary
Lens Mount: Canon EF
Mount: MFT
Included in box
1x EF to MFT Mount Speed Booster ULTRA.

About the Metabones Canon EF to MFT Speed Booster 0.71x
Speed Booster ULTRA for Canon EF lenses to Micro Four Thirds mount cameras, Sharper corners, less distortion, reduced vignetting

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.

List of lenses with autofocus support on Speed Booster ULTRA:

Canon EF primes
EF 14/2.8L II USM
EF 24/1.4L II USM
EF 24/2.8 IS USM
EF 35/1.4L USM (Ver.19)
EF 50/1.2L USM
EF 85/1.2L II USM
EF 85/1.8 USM (Ver.18)
EF 100/2.8 USM macro (Ver.17)
EF 135/2L USM (Ver.17)
EF 200/2.8L II USM (Ver.17)
EF 300/2.8L IS USM
Extender EF 1.4x III
Extender EF 2x (mark I)

Canon EF zooms
EF 8-15/4L USM fisheye
EF 17-40/4L USM
EF 20-35/2.8L (Ver.18)
EF 22-55/4-5.6 USM
EF 24-70/2.8L USM II
EF 28-80/3.5-5.6 II (Ver.18)
EF 28-90/4-5.6 III
EF 35-350/3.5-5.6L (Ver.18)
EF 70-200/2.8L IS USM II
EF 70-200/4L USM
EF 70-200/4L IS USM
EF 70-300/4-5.6L IS USM
EF 70-300/4-5.6 IS USM
EF 100-300/5.6 (non-L, not USM, push-pull zoom) (Ver.18)
EF 100-400/4.5-5.6L IS USM

Tamron
SP 24-70/2.8 Di VC USD A007 (Ver.15)
SP 70-200/2.8 Di VC USD A009 (Ver.31)

Tokina (full frame)
28-80/3.5-5.6 (Ver.18)

Autofocus is DISABLED for the following lenses
Image stabilization (if supported by lens), auto aperture and EXIF work. Autofocus is supported only for those lenses marked with an asterisk (*), on NEX-5R/6, and with adapter firmware version 18 or above.

Canon EF primes
EF 14/2.8L (mark I)
EF 20/2.8 USM*
EF 24/1.4L USM (mark I)
EF 24/2.8 (old version, non-IS)
TS-E 24/3.5L
TS-E 45/2.8
EF 50/1.4 USM
EF 50/1.8 II
MP-E 65/2.8 macro
EF 85/1.2L (mark I)
EF 400/5.6L USM

Canon EF zooms
EF 24-70/2.8L (mark I)
EF 24-105/4L IS USM*
EF 28-70/3.5-4.5 II
EF 35-80/4-5.6

Sigma (full frame)
24-70/2.8 EX HSM
24-70/2.8 EX DG HSM
50/1.4 DG HSM (Ver.17)*
50/2.8 DG Macro
70-200/2.8 EX DG Macro HSM
100-300/4

Tokina
AT-X PRO 28-70/2.8

Zeiss ZE
ZE Distagon 15/2.8
ZE Distagon 21/2.8
ZE Distagon 35/2
ZE Makro-Planar 50/2
ZE Makro-Planar 100/2

List of manual focus lenses which REQUIRE MODIFICATION to be used on Speed Booster ULTRA
Many manual focus lenses have rear protrusions (spikes, levers, other appendages) which would damage the optics and/or housing of Speed Booster ULTRA. They need to be modified before they can be safely used on Speed Booster ULTRA. Check and make sure there are no rear protrusions from the adapter/lens combination before using on Speed Booster ULTRA. Scratches and damages caused by rear protrusions or by poor quality adapters are not covered by warranty. The following is an incomplete list of lenses known to be incompatible.

Leica R
Super-Elmar-R 15mm
Elmarit R 28/2.8
Elmarit R 35/2.8
Summicron R 50/2

Nikon F
20/2.8 AI-S

Olympus OM
OM 18/3.5
OM 21/2
OM 21/3.5
OM 28/2.8
OM 50/1.8

Pentax K
Every Pentax K-mount lens has a protruding fin and an aperture lever. It does NOT fit.

Mount Type Canon EF Lens to Micro Four Thirds Mount

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.