What’s the difference between 1080i and 1080p? Should I buy 1080p or 1080i HD TV?

Some text is quoted from Doug Finck, General Manager of WPXT, Station Manager of WPME.

A more important question is what’s the difference between 1080i and 720p.

That’s because right now and in the foreseeable future, no television shows or movies will be recorded in 1080p. Broadcast, cable and satellite are not capable of delivering 1080p signals (and won’t be in the near future…if ever), the good shows are not going to be created in a format that can’t be appreciated via mass media distribution.

As for the broadcast networks, ABC, Fox, and My Network use 720p, while CBS, NBC, The CW and PBS use 1080i. You would be hard pressed to see a difference between the two.

1080p means 1080 pixels per inch in a “progressive” scan format. 1080i means the same pixels in “interlaced” format. Progressive scan broadcasting offers a higher quality picture so a 720p broadcast is similar to a 1080i broadcast. I’m not going to get into the technical aspect of this but I can tell you that unless you have better than 20/20 vision and you are sitting within 2 feet of your television screen, you don’t even have the chance of noticing the difference between 1080i versus 1080p, or 1080i versus 720p.

There are video snobs out there who call 1080p the only true HD, or Full HD. But does it matter if there is not any programming out there in 1080p and as I said won’t be in the foreseeable future. Broadcasters, cable, and satellite providers aren’t even up to speed on HD in general, let alone full 1080i programming which is the standard and what they are striving for.
Right now, 1080p is only being used for high-end web site video being downloaded (not streaming). The technology, and the need, just isn’t there. And 1080p uses up so much bandwidth over the wires and airwaves that it just isn’t viable in the near future for mass distribution.

Blu Ray and DVD-HD are viable for 1080p but Hollywood isn’t really willing yet to spend the money to get to 1080p.

If you really want to know some details, here’s a formula for determining the optimum screen size and pixel ratio:

The distance you sit from your TV screen determines whether or not you can
see the differences between 720p and 1080i. Specifically, beyond a certain
distance, the human eye and brain cannot see the differences. The formula
for determining that distance is surprising. Take the diagonal
measurement of your HD TV 16:9 screen (let’s use a 37 inch set for example
because that is very common) and multiply that number by 137% (in the case of
our example, that would give you the number 50.69, or just under 51
inches. So, if you are sitting more than 51 inches (or 4 feet, 4 inches)
away from your 37 inch diagonal HD TV, your eye and brain will not be able to
see any difference between the 720p and 1080i image. Most people sit more
than four feet from their TV screen. While a larger screen changes the number (a
50″ screen is “good” only up to 68.5 inches, 5.5 feet) you’re still talking
about distances that are far smaller than the typical living room set up.