Thomas Smet
Veteran
They are built for very specific lens mounts. The last I read the M4/3 version of the Speedbooster may be out in April but there will be no Canon EF version at first. Nikon, Leica and a couple of other not as common lens mount options. You will need a different Speedbooster adapter for each type of lens mount you want to adapt.
I also read the M4/3 version will be manual only with no support for autofocus. Even the Sony mounts for Speedbooster that do have autofocus I understand are painfully slow to the point of being useless.
I also read the M4/3 version will be manual only with no support for autofocus. Even the Sony mounts for Speedbooster that do have autofocus I understand are painfully slow to the point of being useless.