An investigation, based on subjective tests according to ITU Recommendation 500, was carried out to correlate the TV contrast-definition parameters to the subjective quality perceived by the viewers. The results show that high definition pictures (HDTV), with reduced contrast, and standard definition pictures (SDTV), with high contrast, are of comparable quality. Tests were carried out with the HDTV design viewing distance equal to 3 times the screen height (DVD=3H). A test using the preferred viewing distance (PVD) was also carried out. PVD is a subjective parameter and a function of screen height. For the 38", HDTV, 16/9 screen used in this test, PVD was 5.2 H. The results show that the design of new displays for HDTV should guarantee a large screen with adequate contrast in order not to make the higher definition contribution ineffectual.