As Mike has said, the lenses from the Retina II SLR and after fit the Retina S and the Retina Instamatic. The older Retina I, II, IIc, IIC, IIIc, IIIC, as well as the first Retina SLR use a changeable front element instead of a changeable lens. These are interchangeable within that sub-set of cameras, but they cannot be used on the later SLR's - and vise versa. Since the entire lens changes on the later SLR cameras (and the Retina S) the issue of Schneider or Rodenstock lenses is immaterial on these cameras.