This is a quick test of the Canon 24-105/4 and the lovely 10-18 IS STM on the Blackmagic Pocket Cinema Camera.
Please note that I have no idea if the 10-18 can be modified for a EF-Speedbooster. And that it is focus by wire only, in other words, it cant focus or set aperture with a dumb adapter.
They way I was able to focus it was with the zoom. It turns out that zooming shifts the focal plain from near to far.
On the 24-105/4 I could focus fine but of course no aperture control.