Are you sure you want to do this?


Who should we e-mail when a
Metabones Canon EF to Micro 4/3 Speed Booster XL Adapter
becomes available?

Want to add more than this item? Head to our waitlist builder


Metabones Canon EF to Micro 4/3 Speed Booster XL Adapter

Gear Arrives On
Ships Back On
? ? ?
? ? ?

4 Day Rental Price:



*up to 2nd day air - overnight available

The Metabones Canon EF to Micro Four-Thirds Mount Speed Booster XL 0.64x mounts EF glass to certain Micro Four-Thirds bodies such as the Panasonic GH4 & GH5. This pa0rticular XL version is special because it converts the normally super long crop factor of 2.34x when shooting in 4K on a GH4 to a remarkable 1.5x crop, effectively the same as a Super 35 sensor! That's right, your EF lenses will have the same focal length on a 4K GH5 as they would on a C100 Mark II or crop DSLR! The speed of any attached lens is increased by 1 1/3 stops, which means a 50mm f/1.2 lens would essentially be a 32mm f/0.80!!! #MINDBLOWN

Key Features

  • Increase maximum aperture by 11/3 stops
  • Increase MTF.
  • Makes lens 0.64x wider.
  • Build-in electronics to control lens aperture.
  • The lens aperture is set by the controls on the camera body.
  • Powered by camera body. no external power source required. 
  • High performance 32-bit processor and efficient switched-mode power supply.
  • The interior is painted with flocking coating to further reduce the internal reflection. 
  • The tripod foot is detachable and compatible with Arca Swiss, Markins and Photo Clam ball heads.
  • Support Panasonic GH4, GH3, G3, G5, G6, G10, GF3, GF5, GF6, GX1, Olympus E-PL7, Blackmagic Cinema Camera with Micro Four Thirds mount**, Blackmagic Pocket Cinema Camera***

This booster will vignette when used with APS-C lenses below 20mm with the Panasonic GH5 due to the full sensor 4k readout on the GH5. Full frame EF lenses are fine down to the Canon 11-24, but APS-C lenses like the Sigma 18-35 will vignette until 20mm.

We cannot recommend Metabones adapters for professional work. We reached this decision after LensProToGo folks and rental clients experienced repeated failures in the field. Though it might work much of the time, it’s our opinion that this product’s performance is too unpredictable to be trusted on high-value projects. Use for casual testing or try-before-you-buy purposes only. USE AT YOUR OWN RISK!


The Speed Booster XL 0.64x is similar to the Blackmagic-specific 0.64x BMCC Speed Booster (MB_SPEF-BMCC-BM1), but has been completely re-designed to meet the following requirements:


  • The working distance has increased by 1mm to permit use on the Panasonic GH4 and a number of other Micro Four Thirds cameras without touching the flexible outer cover of the camera’s shutter mechanism.
  • The optics are optimized for a standard Micro Four Thirds filter stack thickness of 4mm rather than the 2.4mm found in Blackmagic cameras.
  • The image circle diameter has been increased to 21.63mm so that the full 17.3mm x 13mm Four Thirds format is covered.  This has been achieved while maintaining unusually high image quality over the 17.4mm image circle used by the Panasonic GH4 in its Cinema 4k video mode.


Although the Speed Booster XL 0.64x has extra clearance compared to the 0.64x BMCC Speed Booster, there are still a number of Micro Four Thirds cameras that are not supported due to mechanical clearance issues.  This is summarized in the table below, which is color-coded so that Green means the camera is supported and Red means the camera is not supported. 

Note that many of the Red-coded cameras actually do function, but there is a minor interference with the protective shutter cover.  Although slight contact with the shutter cover appears to have no effect on the functioning or cosmetics of either the camera or the Speed Booster we cannot support these combinations due to possible risk of damage.


*Not yet tested

Metabones Speed Booster XL 0.64x Specifications:

Magnification:  0.64x

Crop Factor for Full Micro Four Thirds format:  1.28x

Crop Factor with GH4 in Cinema 4k (4096 x 2160) Video Mode:  1.5x

Maximum Output Aperture:  f/0.80 (with f/1.2 lens attached)

Rectilinear Distortion:  < 0.8%

Lens Elements/Groups:  6/4

Length Reduction:  6.2 mm

Camera Mount:  Micro Four Thirds

Image Format:  17.3 mm x 13.0 mm (full Micro Four Thirds format)


Supported Not supported 

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)

Distance and zoom display on camcorders (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 2)

External 5 Volt power supply (see note 6)


EF-S lenses (some EF-S lenses may need modification)

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.)

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


  1. Requires lenses supporting distance information.
  2. A third party zoom lens may need to be registered with the Speed Booster/Smart Adapter first in order to detect its maximum aperture. 
  3. This Smart Adapter is designed to cover an 17.3mm x 13mm sensor.
  4. Some improperly-made M42 screw mount adapters may short the electronic contacts of the Smart Adapter and cause damage to the Smart Adapter 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 Smart AdapterThey need to be modified before they can be safely used on Smart Adapter. Check and make sure there are no rear protrusions from the adapter/lens combination before using on Smart Adapter. Scratches and damages caused by rear protrusions on Smart Adapter are not covered by warranty.
  6. For those passive (without electronic pin or without power supply from the camcorder) MFT camcorders, this Speed Booster Adapter can also be powered by external third-party 5 Volt MicroUSB power supply*.
    * ) third-party 5 Volt MicroUSB power supply is not provided in the box. The compatibility of 3rd party power supply can't be guaranteed. 
  7. For use with fast lenses (faster than f/1.8), 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/0.8(Speed Booster XL Max. limit) with a f/1.2 lens attached, but show f/1.2 instead. 


    a) EF 85/1.2L attached, camera display = f/1.2, physical aperture  (lens + Speed Booster combined) = f/0.8 (Speed Booster XL Max. limit).
    b) Sigma 18-35/1.8 attached, camera display = f/1.0, physical aperture (lens + Speed Booster combined) = f/1.0.

Select the correct EF-MFT Speed Booster fits for your camera:

List of lenses (have been tested by metabones) with support on EF-M43 Smart Adapter. (Lenses which have been tested with EF-E Smart Adapter may refer to EF-E Smart Adapter product page.)

Canon EF zooms

Canon 20-35mm3.5-4.5

Canon 28-80mm2.8-4L

Canon 70-200mm2.8L

Canon 24-70mm2.8_II

Canon 24-105mm4_L

Canon 70-200mm4_L

Canon 70-300mm4-5.6L

Canon 70-300mm4-5.6

Canon EF primes

Canon 50mm1.8

Canon 50mm1.4

Canon 85mm 1.2

Canon 100mm 2.8


Sigma 18-200mm3.5-6.3

Zeiss 35mm2


List of manual focus lenses which REQUIRE MODIFICATION to be used on Smart Adapter

Many manual focus lenses have rear protrusions (spikes, levers, other appendages) which would damage the optics and/or housing of Smart Adapter. They need to be modified before they can be safely used on Smart Adapter. Check and make sure there are no rear protrusions from the adapter/lens combination before using on Smart Adapter. 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.


Canon EF Body Cap

Micro Four-Thirds Rear Lens Cap