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.
85/2.8 Carl Zeiss Sonnar Polarizer