Jacek paired the Sony NEX-5 and the Carl Zeiss Jena Tessar 50mm f/2.8 via a Kipon E-mount to M42 lens adapter and here are his results. He stated that "the threaded plate is upside down which means that lens scale numbers are facing down." He has informed Kipon about this issue. The problem is easily rectified with a screwdriver.
Click here to see the rest of the Carl Zeiss Jena 50mm Tessar Photos from Jacek.