... This formulation allows experimental conditions such as the unit cell size, peak size and profile, maximum reciprocal-space resolution and beam characteristics to be included into the design of an area detector. ... If the detector is a square, then the ideal area, AD ideal = sD 2 . ... The application of these criteria to the design of both a laboratory and a synchrotron detector for x-ray crystallography is described in the accompanying article by Stanton, Phillips, O'Mara, Naday and Westbrook [19...