Choice of the T Step or the 2T Pulse for Measuring Short-Time Waveform Distortions in TV Facilities

There are basically three types of short-time waveform distortion: overshoot, undershoot and ringing. Overshoot and undershoot distortions can readily be measured by either the 2T Pulse or the T Step. This is because the flanks of the 2T Pulse and the T Step are identical for all practical purposes, a fact not widely recognized and easily overlooked. Ringing distortions cannot be measured with the 2T Pulse but can be with the T Step. It is shown that TV film and live cameras produce brightness transitions whose risetimes are nearly identical to the risetimes of the T Step.