The optical properties of the large-solid-angle QDQ spectrometer at NIKHEF have been studied. Over the full solid angle a momentum resolution better than 2 × 10 -4 for electrons is achieved. By particle back-tracing the target vector can be reconstructed with high precision: 7 mrad (FWHM) angular resolution in the dispersive direction and 8 mrad (FWHM) resolution in the scattering angle. The nondispersive target coordinate can be reconstructed with a resolution better than 1 mm. As a result, (e, e' p) coincidence experiments, with the QDQ spectrometer used for hadron detection, can be performed with 75 keV (FWHM) missing-energy resolution and a timing resolution better than 1 ns (FWHM).