I’ve collected some data for you regarding HDTV and viewing distance…
Basically, for HDTV you need to sit about 2x the diaganol size of your TV… And 5x or greater for Standard Def…. So for a 50-inch TV you need to sit 50*3/12 = 12.5 feet close-in to notice the detail on HD. Sitting further away means you’re just paying for pixels you can’t see.
What this also means is you can’t take a room designed for Standard Def viewing, replace the TV and expect it to be ok for HDTV… So once you configure your seating and HDTV correctly you’ll find that you “feel” like you’re sitting too close to the TV – but in actuality you need to be sitting that close to preceive the details in the image at HD resolutions.
So most folks with HDTV aren’t really getting much benefit from their HDTV set because they’re sitting too far away.
While the following clips don’t all say the same thing, they are all essentially saying that you need to sit pretty close to the set… With an outer max of 4x if you have really-really good vision (hence my rule of thumb of 2 to 3x)
furniture.com – “For high-definition, wide-screens … sit at a distance 1.5 to 3 times the diagonal width of the screen.”
ezinearticles.com – “five times the screen width as the maximum view distance, while more than adequate for a standard analog TV picture, is a bit too far away for a person to see the fine detail supported by a HDTV picture – a three to four times the screen width represents a more practical limit for the maximum viewing distance in the case of HDTV.”
Call for Help – “With a high definition TV the optimal viewing distance is between 2 and 3–4 times the width of the TV. Remember, if you sit too far away for the size of TV you will not realize the sharp detail of HDTV”
My-Home-Theatre.com – “For optimal viewing of high-defenition images, the distance between the viewer and the screen should equal about 1 1/2 to 2 1/2 times the screen size”
So – those of you with HDTV sets… break out those tape-measures and move your sofas!