August 9, 2016 at 2:21PM, Edited August 9, 2:45PM


Speed booster for EF Mount camera body

Is there a speed booster for EF lenses to a EF mount camera? I'd like to get a wider field of view and gain a stop on my Ursa Mini 4k's super 35 sensor.


If I understand correctly what you are asking is to make a full frame lens (EF) into a cropped frame lens (EF-S). In theory someone could make this but it would be complicated because not only do you have to change the focal length as the speed booster does you also need to correct the flange focal distance because such an adapter would have a minimum thickness and the flange focal distance for EF and EF-S lenses if pretty much the same.

Your best bet is to use crop frame lenses in the first place such as the sigma EF-S lenses.

August 9, 2016 at 2:38PM

Cary Knoop

I see what you mean. Thanks

Grant Reinero

August 9, 2016 at 2:43PM

i no have sigma lens, but... are you sure that a EF-S lens not have crop on aps-c camera?
with canon i had many ef-s zoom, also last 17-55 2.8 canon which is a 1200$ lens, and if i put in 50mm i had same field of view from EF 50mm 1.2, that seems it ad crop at same way, same thing with 35mm 2.0 and more... seems that canon with zoom ef-s not build an ef-s lens, only mount an ef-s lens rear, but optical build is the same of ef, with loosing of view angle.

Carlo Macchiavello

August 12, 2016 at 2:44AM

SpeedBoosters are designed for mirrorless cameras that have a much shorter distance from the lens mount to the camera sensor than a traditional Canon EF DSLR. This short mount distance allows for the optics and the lens mount-adapter of the SpeedBooster to fit in between the lens and the camera body and still KEEP accurate focus with your Canon lenses.

So SpeedBoosters are ONLY available for Micro 4/3 and Sony E mount mirrorless cameras.

August 9, 2016 at 6:39PM, Edited August 9, 6:39PM

Guy McLoughlin
Video Producer

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