... SCORPIO is a multi-mode focal reducer of the BTA. It it used for observations of star-like and extended objects in following observational modes at the prime focus (F/4) of the 6m telescope: . ... Long-slit spectroscopy . ... The device consists of the Focal Reducer (F/2.6) and of the prime focus Adapter (with tip-tilt auto-guiding system and lamps for flat-field and wavelength calibrations). ... SCORPIO design: . The optical part contains of the collimator (F/2.2) and the camera (F/1.8). ...