TV resolutions- 480i, 480p, 720p, 1080i, 1080p

Week of March 19, 2006

Q: I have a Toshiba HDTV with a 1080p display. Does it convert the 480p signal from my progressive-scan DVD player to 1080p? Do I gain anything from an upconverting DVD player (such as the Oppo 971) if my Toshiba is already outputting a 1080p display? In any event, I’m very happy with the picture.

-Bob Kuhn, Minneapolis MN

A: Any signal going into your TV will be converted to 1080p for display. More on this later, but first, some background for the rest of our readers.

Numbers such as 1080p, 1080i, and 480p refer to screen resolution. The number is the lines of resolution; the higher the number, the better the picture quality. Resolutions of 480 the maximum given for are standard definition television, the format we have been watching for many years. Figures of 720 and 1080 are HDTV quality.

The i and p refer to scanning, either interlaced and progressive. Interlaced scan draws the picture in two separate, interlaced fields. This happens very quickly so to the viewer it looks like a single image. Progressive scan draws the entire picture in a single pass, producing superior picture quality than interlaced, especially with fast-moving subjects such as sports. This is one reason ABC and ESPN (daughter company of ABC) chose 720p for their HDTV broadcast format.

The most common figures you will see given for TV and DVD players are 480i, 480p, 720p, 1080i, and lately, 1080p. The 720p, 1080i and 1080p were specified when the new HDTV format was developed. The 1080p specification of your Toshiba is tops- it combines the highest lines of resolution with progressive scanning. Standard definition TV only has a 480i specification; the 480p came later with the advent of HDTV. When HDTVs were introduced, they supported higher scan rates that allowed them to reproduce a 480p image. Realizing the potential for better image quality, electronics manufacturers developed progressive-scan DVD players. These players take the picture information from the DVD and digitally convert it into a progressive-scan image before sending it to the TV, yielding a better picture.

Whatever signal is fed to your TV will have to be converted to 1080p for display, its native display rate. If you feed it an analog 480p signal from a DVD player, it will be upconverted by the TV to 1080p. It will still look great, but some picture quality may be lost. It is usually better to do upconversion in the player instead of the TV, if possible.

An upconverting DVD player takes the progressive-scan DVD player a step further. Instead of simply assembling the 480-line picture progressively, it converts it to an HDTV resolution such as 720p or 1080i before sending it to the TV. It does not create an HDTV image, but if the upconversion is done well, you will get a better picture than you would with a 480p DVD player. If this upconversion is not done well, it will have picture defects and may look much worse than a standard 480p image. Not all players do upconversion well, and some have been noticeably bad- one of several reasons I recommend the Oppo so strongly. It’s only $200, has proven to be a top-grade performer, and is very well supported by the manufacturer. Though it outputs 1080i and not 1080p, I do think it will yield a better image than your 480p progressive scan player and is worth the investment. You can see it at

Now- your 1080p Toshiba. As I noted before, the 1080p specification is the best available. However, at present no 1080p video sources exist to feed it a 1080p signal, so everything coming in will be converted to 1080p. As you have noted, it looks great and you are happy. Fact is, most people ARE happy with their HDTV picture, be it 720p, 1080i, or 1080p. Well-done HDTV in any form looks magnificent, and more variations in picture quality will be seen between different models of TVs than the display resolution. I think we get obsessed with number crunching sometimes! When shopping, don’t choose a HDTV based on numbers, but by looking at the picture it produces.

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