I'd like to try an NN5+RD16 with a long lens, say a 300mm on full frame, or 200mm on aps. It looks like the RD16 should work fine if I mount the camera in landscape. Problem is, the vertical displacement. As I understand it, the NN5 only has 15 degree stops -- right? Is it possible, and if so, is it a good idea, to adapt a 2nd RD16 to use as the top rotator on the NN5?