A method for use in characterizing a digital imaging system (53) having an array of imaging elements (35), and in particular for measuring the modulation transfer function (sometimes called the spatial frequency response) even in directions (33) at large angles to both horizontal rows and vertical columns of the array of imaging elements (35), wherein at large angles compared to either horizontal rows or vertical columns of the array of imaging elements (35)--and even at angles other than for directions lying along a diagonal to the array of imaging elements--only non-interpolated readings of the imaging elements (35) are used in determining a supersampled characterization of the digital imaging system (53).