Metabones EF to EF-M T Speed Booster ULTRA 0.71x (EOS M) (MB_SPEF-EFM-BT1)

Metabones EF to EF-M T Speed Booster ULTRA 0.71x (EOS M) (MB_SPEF-EFM-BT1)

Sharper corners, less distortion, reduced vignetting

Optical design: advanced 5-element/4-group optical design incorporating ultra-high index tantalum-based optical glass to achieve extraordinary optical performance with improved corner sharpness, distortion and reduced vignetting.

Optical
• Increase maximum aperture by 1 stop. (with a maximum output aperture of f/0.9).
• Increase MTF (details).
• Makes lens 0.71x wider.
• Advanced 5-element/4-group optical design incorporating ultra-high index tantalum-based optical glass by Caldwell Photographic in the USA (patent granted).

Electronic
• Autofocus. AF speed is properly adjusted to account for and leverage the shorter focal length and the brighter maximum aperture.
• Focal length and aperture are adjusted in EXIF (see note 3).
• Image stabilization (IS) lens support.
• Video Digital IS support (on supported camera bodies).
• Store EXIF data (lens name, focal length and maximum/minimum aperture) for one manual lens in the adapter.
• LED indicator shows communication status.
• Powered by camera body. With most lenses, no external power source required.

Mechanical
• The tripod foot is detachable and compatible with Arca Swiss, Markins and Photo Clam ball heads.
• Flocking to reduce internal reflection.
• Rubber gasket protects EF-M mount connection from dust and moisture.
• Aluminum alloy and brass construction with chromium plating.
• Satin surface finish.

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(APS-C), 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 full-frame 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.

Compatible Lenses
• Canon EOS M series camera
• Canon EF-mount Lens
• Canon EF-Extender (Teleconverter)
• Carl Zeiss EF-mount Lens (see note 2)
• Sigma EF-mount Lens (see note 2)
• Tamron EF-mount Lens (see note 2)
• Tokina EF-mount Lens (see note 2)
• Contax N mount lenses modified to Canon EF by Conurus
• Contax 645 NAM-1 adapter modified to Canon EF by Conurus

Unsupported Lenses
• Canon EF-S Lens (see note 1 & 2)
• Lens correction such as peripheral shading, CA and distortion
• Focus confirmation chip (e.g. Dandelion)
• M42 screw mount adapters (see note 4)
• Stacking non-Metabones/non-Conurus mount adapters on top (see note 5 and list of lenses which require modification below.)

Note:
1. EF-S lenses do not fit on Speed Booster®. Some EF-S lenses may be modified to fit, but do so at your own risk.
2. Third-party lenses designed for APS-C format work only with cropped 4k video mode of EOS M50. They do not have enough coverage for still photography or full HD video when used in conjunction with Speed Booster®.
3. For use with fast lenses (faster than f/1.4), the pre-boost apertures will be displayed in the camera.
Slow lenses will report boosted apertures to the camera body but fast lenses will report pre-boost apertures. We wont show f/0.9 with a f/1.2 lens attached, but show f/1.2 instead.
Example:
a) EF 85/1.2L attached, camera display = f/1.2, physical aperture (lens + Speed Booster® combined) = f/0.85.
b) Sigma 35/1.4 attached, camera display = f/1.0, physical aperture (lens + Speed Booster® combined) = f/1.0.
4. Some improperly-made M42 screw mount adapters may short the electronic contacts of the Speed Booster® and cause damage to the Speed Booster® and/or camera body.
5. Many manual focus lenses (e.g. OM 28/2.8, OM 50/1.8, Leica R 15/3.5) have rear protrusions (spikes, levers, other appendages) which would damage the optics and/or housing of Speed Booster®  They need to be modified before they can be safely used on Speed Booster® Check and make sure there are no rear protrusions from the adapter/lens combination before using on Speed Booster®. Scratches and damages caused by rear protrusions on Speed Booster® are not covered by warranty.