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Old April 1st, 2004, 03:24 AM   #1
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why is it 1080i?

Just wondering,

why is HD 720 Progressive but 1080 is interlaced ?

Seems its going backwards, obviously there is a reason for this.

HDCAM is 1080P?


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Old April 1st, 2004, 08:25 AM   #2
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Just a guess, but maybe the 720p is 16/9 and the 1080i is 4/3. Note that (720*2)/1080=1.33 and that (16/9)/(4/3)=1.33.
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Old April 1st, 2004, 08:33 AM   #3
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720 and 1080i are both 16:9. There's also 1080p that's used for "film" aquisition. Why i then? because it offers greater temporal resolution - 60fields per second as opposed to 24 or 30, hence better for sporting action, like the 720p 60fps, which due to being lower resolution, can do 60 frames rather than 60 fields.

interlaced is not the problem it used to be, especially now that there are a number of high quality de-interlacers....

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Old April 1st, 2004, 08:36 AM   #4
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It's due to size. The size of an 1080p signal is quite big. Also some have stated that 720p looks as good as 1080i with less bandwidth. At least that's some of the things that I have heard. I have also heard that they are using 1080p for shooting movies in HD.
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Old April 1st, 2004, 10:11 AM   #5
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The reason is you can't fit 1080p into the bandwidth allotted.

720p is better than 1080i because you are presented with only 640 lines per frame at a time with 1080i.
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Old April 1st, 2004, 11:48 AM   #6
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I thought the question and answers in this thread would be about the number itself. I wonder where 1080, 1920, 720, 480, 576 and all those actually come from. I mean why those numbers and not others?
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