Originally Posted by Mando E
I have Directv, and I noticed that my receiver has a light for 1080p; however I'm only able to use the 1080i. I went into settings and yes the option to handle 1080p is checked.
I moved it to 720p and the picture looks better than 1080i.
I have the 55' HX 750.
Odd, I always thought that 1080 trumps 720 any day.
I Think that HDTV broadcasts from your local TV station, cable, or satellite service are either 1080i (such as CBS, NBC, WB) or 720p (such as FOX, ABC, ESPN) but not 1080p.
So...720p is 1,280 pixels across a screen horizontally and 720 pixels down the screen vertically. This arrangement yields 720 horizontal lines or pixel rows that are sent to a TV or other display device progressively, or each line sent following another (that is where the "p" comes from). In other words, the entire image (720 lines or pixel rows) is sent every 60th of a second (or twice every 30th of a second).
1080i represents 1,920 pixels arranged horizontally and 1,080 pixels arranged vertically. This yields 1,080 horizontal lines (pixel rows), sent to a TV alternately (referred to as an interlaced signal). In other words, all the odd lines or pixel rows are sent to the TV, followed by all the even lines or pixel rows.
This means that 1080i, since it is interlaced, only sends 540 lines (or half the detail) every 60th of a second, with all the detail sent every 30th of a second. On the surface, 1080i produces more detail than 720p, but since the increased detail is only sent every 1/30th of a second, rather than 1/60 of a second, fast moving objects, will exhibit slight interlacing artifacts - which can appear to look like jagged edges or a very slight blurred effect.
We also have to consider that all lcd or plasma or dpl tvs can only display progressively scanned images, they cannot display a native 1080i signal. If a 1080i signal is detected the TV has to scale the 1080i image to either 720p (if it is a 720p TV) or 1080p (if it is a 1080p TV). As a result, the quality of the image you see on the screen depends on the how well the TV's video processor works - some TVs do better than others.