A Canon EF to MFT (micro four thirds) speedbooster has been long awaited, however for a lot of people the wait continues as this adaptor is made for use with the Blackmagic Pocket Cinema Camera only.
Metabones has made this very clear, and early reviewers Andrew Reid and James Miller have both confirmed its lack of direct compatibility with the likes of the Panasonic GH4. To confirm, this adaptor is only designed for use with the Blackmagic Pocket Cinema.
Metabones first announced camera specific speedboosters towards the end of last year, bringing out two unique adaptors that worked with the Blackmagic Cinema Camera and Pocket Cinema. Both offered increased magnification compared to standard speedboosters, adapting Nikon G (and later Leica R) to MFT.
The new Canon EF to BMPCC adaptor offers the same specification as the previous Nikon G and Leica R equivalents, however this is an active adaptor, meaning aperture information is transferred electronically, as well as providing power for Image Stabilization with compatible lenses.
The Canon EF BMPCC offers a speedboost factor of 0.58x, this reduces the crop factor to 1.75x. Figures like these can get a little confusing, so please see the below graph for reference of how this affects your lens.
Many document the crop factor of the BMPCC as 2.88, however Metabones record it at 3.02. The above graph adheres to Metabones calculations, as well as Canons APS-C crop factor of 1.6.
In reference to calculating the focal length and the new Canon EF speedbooster, you simply times the focal length of the original lens by the sensor crop factor, then times that figure by the speedboost:
(50mm X 3.02) X 0.58= 87.5mm.
An easier way, is to times the sensor crop factor by the speedboost to establish a new crop factor, then times the focal length by this figure.
3.02 X 0.58 = 1.75
50mm X 1.75 = 87.5mm
This is how the advertised crop factor of 1.75 is produced.
The new adaptor is noticeably slimmer than its Nikon counterpart, also utilizing superior Caldwell Photographic optics.
The current firmware on the BMPCC does not enable display of apertures wider than f/1.0. To avoid conflict with this, Metabones has designed the adaptor to relate aperture information relative to the physical size of the aperture, not the predicted speedboost figure.
Whilst EF-S lenses share the same lens mount as EF, the flange distance is slightly different (EF-S protrude a little further back). Because of this, EF-S lenses are listed as un-compatible with the Canon EF BMPCC speedbooster. Andrew Reid rightly pointed out in his blog that all third party (non Canon) EF-S lenses actually adhere to the EF mount, so this will not affect the likes of the Tokina 11-16mm and the Sigma 18-35mm (probably the two most popular EF-S lenses for video around).
Check out this video by James Miller using the Blackmagic Pocket Cinema with Canon EF BMPCC Speedbooster:
Lens collections are often a filmmaker’s greatest investment and can often sway the decision of picking a new camera body between another. What Metabones is doing is fantastic, by continually offering more and more adaption between different lens mounts it is becoming easier to own different camera brands with different sized sensors.
Gone are the worries of multiple lens setups for each camera. A non Blackmagic specific Canon EF to MFT is on the way, and when that arrives it really leaves the door wide open for migrating DSLR users to the likes of the Panasonic GH4.
The Canon EF BMPCC Speedboost will retail at $659, availability imminent.
Photos by Philip Bloom