The introduction of high-definition television (HDTV) offers important improvements for user experience in terms of the quality of the image (definition) as well as the sensation of reality (immersion in the scene). However, until broadcasts are transmitted in a single HD format, there is going to be a transition period of several years in which the three current digital TV formats (standard definition (SD), HD720, and HD1080) will coexist. Taking into account that each of these formats has its own optimal TV size (based on viewing distance), it is not a simple matter to determine which size TV will offer the best image quality across all three formats. This paper analyzes optimal viewing distances, and proposes an optimal as well as a practical solution to deal with this situation. © 2013 Alcatel-Lucent.