Ok. Here comes a rather basic question: what exactly does the Birger mount do?
(I've found absolutely no information on the Birger website, and have spent 2 hrs searching the reduser archives, to little avail.)
http://youtube.com/watch?v=C7t6W2cWzMw
Allows use of Electronic lenses with no aperture. Electronically controls both focus and aperture. Eventually will include wireless remote follow focus and image stabilization using Canon IS lenses.