Remember when you were a kid, and your parents used to yell at you, "Don't sit too close to the TV"? Well, that was back when TVs weighed as much as a person and had curved, fish-bowl fronts and consumed enough electricity to power the Griswold family Christmas tree.

Now, we're going all digital. We've ditched picture tubes for flat screen plasmas and LCDs. OLEDs are just around the corner. And now, we find out we need to move closer to the TV.

HDTV is broadcast in one of two resolutions: 720i/p or 1080i/p. Standard TV produced a paltry 535×240 pixels on the screen at once — pixels being those little glowing specs that form the picture you see (that's 128,400 dots forming your picture). That's more than a LightBrite, but still, not that impressive. HDTV, broadcast in brilliant 1080p cranks out over 3,000,000 pixels. Yes, THREE MILLION pixels. Comparing 1080p to SD (Standard Definition) is kind of like comparing your old analog TV set to a LightBrite.

And, any good home theater fan knows that the distance you sit from your TV should be very precise. To keep the field of view just right, you have to adjust your distance based on the size of your set. Say you have a 46″ TV, then you should be sitting  5.75 to 9.5 feet away, so you have the optimal field of view (you don't want to have to turn your head back and forth to watch your movie).

But now, there's a new twist to viewing distances and resolutions: The Lechner Distance. Apparently, this guy, Bernard Lechner, figured out that when you're sitting nine feet from your TV, it's hard to make out all that wonderful 1080p detail.  Apparently, if you are watching 1080p at nine feet, you need a 69″ TV to get the full effect. If your TV is only 720p, your eye can distinguish the wonderful detail at nine feet on a 46″ screen.

Hmmm… So, seeing as how the national average for viewing distance is nine feet, do you want to buy a 1080p 69″ set, costing you over $1300 for a DLP, or a nice, crisp, clean 46″ LCD set for about $900?

Already bought your HDTV? Is it a cost-effective 37″? Well, forget what Mom said, man, you better sit closer to the set to get your money's worth.