The optical layout of the QBM Sonnar was slightly different from the C/Y type as shown below. 

     

                                Rolleiflex QBM                                                                                  Contax C/Y

85mm is a focal length  I rarely used. This is the lens I bring along when I travel as it is small and compact. It is not as hard as the Planar, and has the very smooth character of Sonnars.

 

 

SL2000F, f5.6 1/30-1/60, 85/2.8 Carl Zeiss Sonnar + Polarizer, 25 May 1999