# Resolution numbers



## dude2 (May 28, 2006)

When you see the specs: 1920x1080i is that refering to the number of scanlines that can be sent accross the tv screen? Also which number refers to the horizontal scan and which one to the vertical scan.
Also why aren;t they the same, like 1080x1080i?


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## P Smith (Jul 25, 2002)

look in your TV ( HiDef ? right ?) manual, cool dude2


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## dave1234 (Oct 9, 2005)

dude2 said:


> When you see the specs: 1920x1080i is that refering to the number of scanlines that can be sent accross the tv screen? Also which number refers to the horizontal scan and which one to the vertical scan.
> Also why aren;t they the same, like 1080x1080i?


Here's the simplified version:

1920 refers to the horizontal resolution, there are 1920 pixels in the width of the picture on the screen.

1080 refers to the number of vertical scan lines.

The aspect ratio of the HD screen is 16:9, that's why there are more horizonal pixels than vertical scan lines.

Note that 1920/1080 = 16/9.


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## zmark (Apr 18, 2005)

And note that with HDTV, we're talking about actual pixes just like with computers. Not like with analog TVs where resolution is measured in scanlines with the constant debate of scanlines vs. pixels.


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## harsh (Jun 15, 2003)

zmark said:


> And note that with HDTV, we're talking about actual pixes just like with computers. Not like with analog TVs where resolution is measured in scanlines with the constant debate of scanlines vs. pixels.


If you're going to launch a preemptive strike, you must have your facts straight.

Analog resolution is measured as how many vertical lines can be distinguished, not (horizontal) scan lines. It is arguably a much more meaningful metric than pixel density because it factors in the video processing hardware and algorithms.


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