I have been testing my Canon 100-400 lens mounted on a Sony NEX6 using the Metabones Speedbooster Adapter. Scroll down and click to see the video below. As you can see its rather unbalanced and whichever way you look at it is either ridiculous or cool! – what do you think?
The first lens I attach to it is the Canon 17-40 L.
Don’t forget that with the Speedbooster an extra stop is gained, which makes this quite attractive mounted on the NEX6 to catch those moving animals or in lower light.
The Canon 100-400 is an awesome long range zoom lens which I used for most of my wildlife photography (paired with the Canon 5D mark2 )
I have also done another test review on the Metabones speedbooster paired with the 50mm 1.4 (making it a shocking F1.0) View here