The final status of the optical design of the Russian–German soft-X-ray beamline at BESSY II is presented. Ray-tracing calculations provide the optimized parameters of the optical layout based on a Petersen-type plane-grating monochromator that operates with collimated light. Resolving power up to 25,000 and photon flux up to 3×10 10 photons/s/100 mA with a slit width of 20 μm will be available for spectroscopic experiments.