However, the Rectimascopes are dual focus like many other scope lenses (Kowa, Moeller, Sankor) and I'll soon have the ability to test how this handles in real shooting. But I wonder if it is not possible to use a camera with continous autofocus for the rear lens at all. This way one would only have to focus the anamorphic lens and the rear is adjusted by the camera with contrast autofocus. No reason to fear the autofocus might adjust to the backround in this setup, though.

I have a Canon 60D and no autofocus lens at the moment since I use my old Contax/Yashica lenses for video and also photos but what I've read in the manual their autofocus won't allow for continous and fluent focus revision during REC. But a Panasonic GH series camera might do the trick. Eventually there is somebody who already tested this approach?