AbstractPerceived sharpness is investigated for computer monitor tube (CMT) as well as for television tube (TVT) applications in a number of subjective evaluations using a test pattern and natural images blurred by Gaussian filters. For CMT applications, the visibility of differences in perceived sharpness is determined based on a simple black‐and‐white test pattern. This pattern is either blurred in the horizontal direction only or in both the horizontal and vertical directions. Subjective evaluations demonstrate that the perceived sharpness is related to the diagonal step response, determined from the horizontal and vertical step responses measured at the black‐white transitions. For TVT applications, perceived sharpness is evaluated in three additional experiments, using mainly natural images and trained as well as inexperienced observers. For these experiments too, the diagonal step response describes the decrease in perceived sharpness for an increased degree of blurring very accurately.