The performance of the Siemens SMART CCD (chargecoupled device) area detector has been tested to assess its suitability for accurate electron-density (ED) determination. 92 043 diffraction intensities (14 701 unique reflections, 65 h experiment) have been collected on a reference crystal of methyl 2-[(4-butyl-2-methyl-6-oxo-(C30-H30N603S) at T = 120 K and compared with those (51 485, 14 699 unique, 600 h) obtained from a previous collection at T = 18 K on the same crystal using a diffractometer equipped with a conventional detector. Results from spherical and multipolar refinements (agreement factors, standard uncertainties of refined variables and geometries after correction for thermal motion) have also been compared. The M2 contamination, which affects area detectors but not well tuned conventional detectors, has been carefully investigated and proved to be a negligible source of errors (which can anyway be easily corrected). The encouraging results of this test prove that area detectors are also well suited for charge-density studies, offering a cheap and fast datacollection mode, without loss of accuracy, which can be exploited for ED studies on large systems.