I have just taken delivery of a Contax-to-Lecia adapter and have taken some snapshots with the RD-1 and 50/1.4 Sonnar 7135xx. Whhooo. What fun. Funny thing . . . the Nikon 50/1.4 seems to focus well up close and wide open. Attached pic was with the Zeiss Opton at f8 (I think).