They are the same. The 1080i/p distance for a given screen size is the maximum distance from the screen where person can perceive all the resolution in the picture. If you move between the 1080p and 720p distance the 1080p image will be sharper. When you reach the 720p distance and beyond for a given screen size you will not be able to perceive the higher sharpness of the 1080p display over the 720p display because you are to far away from the screen for your eyes to resolve the 1080p screens higher resolution.

HD Guru

Providing the “distance” data out to 2 decimal places is MEANINGLESS. It just clutters the table and needlessly makes it more difficult to interpret.

Rounding distance results to the nearest inch, and the “diagonal” to the nearest 0.5″ is sufficient. Adding more decimal places just makes it less useful.

Similarly, providing the height and width values is redundant. You have already provided the most often specified physical screen attribute, the “diagonal”, and you specified the aspect ratios…so the H&Ws are redundant and again…that clutters up the table and needlessly makes it more difficult for people to follow the rows/columns and actually use the results.

Lastly, you might consider adding a reminder to people to be sure the vendor’s specified “diagonal” is the maximum image diagonal…and not just the physical diagonal. For example, I’ve seen a disreputable vendor try to sell a 24″ image capable TV as a 28″ TV by using a tape measure to “prove” to them it measures 28″ from corner to corner of the exterior of the TV head. They tried to tell the customer it was mis-marked on the tag so they were “actually” getting a 28″ display for the price of a 24″ display…what a super deal!

Sitting farther back, while remaining at the same horizontal and/or vertical position relative to the screen, reduces the sometimes very obvious color, contrast, and brightness shifting that can often destroy a viewing experience on those screens with more limited viewing angles. This is because as you move back the absolute offset angle at which you were viewing portions of the screen decreases.

–this is where optical colors come into play, such as bluegreen or is it red/green as a primary color since if one stares at primary charted/segmented color then looks away at a white sheet their eyes “create” the primary/secondary color automatically from the previous color. Neat huh? :)

–now if we had the optics of the sea http://www.livescience.com/technology/091025-mantis-shrimp-eyes.html

–this could explain why colors/objects bend before our eyes, columns from far away (entasis), or similiar illusions–like staring at a chair leg through a chairs enclosed arm–the leg becomes distorted in the optics–probably new color is happening here and our eyes cannot handle it(refraction of light too), so the consequence is bluring.

So in essence, feet and distance to matter espeically if one wants to spend bundles on networking and video elements–understanding the aggregate is essential.

(For those who don’t know, 20/16 is better than 20/20 for seeing at a distance)

for 16:9, 1080i/p:
D = 1.568 * I

for 16:9, 720p:
D = 2.352 * I

1080 set “I” inches, sit “F” feet,

~ F = I/7.6 (1080)

720 screen I” inches sit “F” feed,

~ F = I/5.1 (720)

16*9 screen

~ Width = 87%*I, (16*9 diag)

4×3 screen

~ Width = 80%*I (4*3 diag)

16*9 high definition screen diagonal “HD” whose picture is the same height as 4*3 standard definition’s screen’s diagonal “SD”,

~ HD = 122%*SD

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I am purchasing an HDTV for our bedroom and will watch lots of sports. We are 140″ from the tv when in bed. Our space will not accomodate larger than a 40″. What is your recommendation on screen size and pixel resolution?