What does it mean for 720p to be 1080i compatible?

mcidfta200

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I don't understand this, does this say that the 1080 signal gets converted to 720? Is it possible to use a 1920 resolution on this?
 

Ilander

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It's all about vertical resolution, IIRC, and that means you usually need 1920x1080 or higher....otherwise, you have to downconvert to 720p, which is a lower resolution.
 

lakedude

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Ok first things first. The "p" stands for "progressive" and the "i" stands for "interlaced". Progressive scan draws the whole screen every time and is better than Interlaced which only draws half (every other line) the lines each time. So p>i, got it?

You need a screen that has at least 720 (native) lines of resolution to be "720" and 1080 lines of resolution to be "1080".

Now here is the tricky part. Read carefully: Some monitors (like my 50") have a resolution of less than 1080 (like say 1366 by 768). Having 768 lines of resolution makes this monitor a 720p monitor (more or less). It is NOT a 1080 monitor since it has less than 1080 lines of resolution. It can however down convert a 1080 signal so it is called "1080 capable" or some such nonsense. What this means is that if your source is outputing a 1080 signal the monitor's electronics can accept the 1080 signal and produce a watchable display (instead of garbage or an "out of range" error message) but the resolution is reduced to (basically) 720p.

A true 1080 display would have a resolution of 1920 by 1080 (or so) AND also be able to accept a 1080 signal. My 1366x768 display accepts the 1080 signal but does not display in full 1080 resolution.

Confused? Sorry if that didn't come out clearly.

Why do you ask BTW?
 

mcidfta200

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No, that's perfectly clear, thanx for taking time to explain it to me.

Well, the reason I as is because I would like to buy a new LCD to use as a monitor and tv, but I keep seeing lcd's which are 1366 or whatever resolution, and stating that are 1080i compatible... which made no sense to me since it's a not 1920 x 1080 resolution lcd.

I guess a 37" would be nice... I tried my friend's 42", but it's just too big to sit up close to (I have bad eye vision from far away, so I must be up close to see detailed things). I am just trying to figure out if a 720p will be good for me... I run my screens on 1280 x 800, which I like the most, not too small or too large.

 

lakedude

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I've got a friend with a 32" 1366 by 768 LCD. He uses it for both TV and computer purposes in a bedroom. It works pretty darn good for both and didn't cost too much. A higher def/res set would be even better. Go to Wal-Mart or BestBuy (or Circuit City or where ever) and view their demo monitors from the same distances you would be using at home. If the pixel size on the 720p sets bothers you then get the higher res monitor. Same goes for deciding between 42 and 37 inch. You will be able to sit closer to a smaller set with higher res (finest dot pitch) than a larger set or one with lower resolution.

EDIT: Displays look smaller in a huge store than they will in your home. Somehow on the way home they "grow".
 

wenfeng cao

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it is not very clear about the question.So may be you should detail it and then we can give accurated reply that will meet your demand.