Metabones announces the EF to EF-M speedbooster

I guess Viltrox coming out with the focal reducer for the EF to EF-M got Metabones to wake up.

Metabones after many years of rumors finally has come out with a speedboster for the EF-M system. Mount your EF lenses on the EOS M system with this adapter, and they will function as if the focal length is the same as full frame.  For instance, usually, when you put a 24-70 on your EF-M system with an adapter, because of the crop factor the equivalent focal length becomes 39mm to 112mm.  However, when you use this adapter instead, the equivalent focal length is 27 to 80.  Much closer to how the lens would be on a full frame camera.

You can purchase metabones adapters directly from metabones, or from B&H Photovideo.

Press Release

Vancouver, Canada, May 2, 2019 – Metabones introduces the latest member of its award-winning Speed Booster family of DSLR (digital single-lens reflex) to mirrorless lens mount adapters, EF-EOS M Speed Booster ULTRA 0.71x. Full-frame Canon EF-mount lenses are now one stop faster, 0.71x wider and with increased MFT (note 1) on Canon EOS M cameras. The 4k/UHD video crop on EOS M50 can also be mitigated with third-party APS-C lenses using this Metabones Speed Booster. Some Canon EF-S lenses may be modified to fit on the Speed Booster but Metabones cannot be held liable for any issues arising from modifications. Using APS-C lenses with Speed Booster for still photography or full HD videography may result in vignetting.

Ever since the first Speed Booster was introduced, there have been DIY attempts to modify it to fit EOS M cameras. The turnkey solution Metabones now offers adds a number of refinements:

• The optical housing is redesigned for perfect fit on EOS M.
• The EXIF metadata is changed to reflect the faster aperture (note 2) and shorter focal length.
•  The autofocus speed of the lens is adjusted and optimized for the change in focal length and aperture to ensure the best performance. This is especially important for dual-pixel autofocus (DPAF) in video mode.
• A ‘chip’ mode is added so that the user may store the metadata of a fully mechanical manual lens in the adapter.
• A LED indicates operational status of the Speed Booster.

Since both the lens and the camera speak the same protocol most features are supported with the exception of lens aberration correction, which is automatically turned off.

Technical Details and Key features

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.

Compatibility with EF lenses

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 won't 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.

List of manual focus lenses which REQUIRE MODIFICATION to be used on Speed Booster^®

Many manual focus lenses 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 or by poor quality adapters are not covered by warranty. The following is an incomplete list of lenses known to be incompatible.