While it is always a matter of personal preference, I believe the recommended "standard" is with the center of the screen level with the viewer's eyes...???Ideally, seated eye height is even with 1/3 up from the bottom.
In other words, 1/3 of the image below the eyes, 2/3 of it above.
While it is always a matter of personal preference, I believe the recommended "standard" is with the center of the screen level with the viewer's eyes...???
http://www.practical-home-theater-guide.com/Tv-viewing-distance.html
http://www.thx.com/consumer/home-entertainment/home-theater/hdtv-set-up/