On 21 Dec 2002 00:45:23 -0800, greglee@umich.edu (Gregory Lee) wrote:

>I think I'm a bit confused over horizontal and vertical resolution,
>due to this website's table (if you scroll down a bit)
>
>http://www.ee.washington.edu/conselec/CE/kuhn/hdtv/95x5.htm
>
>If I understand correctly, PAL has 625 lines of vertical resolution,
>NTSC has 525 lines of vertical resolution, and HDTV has 1050 lines of
>vertical resolution; is this correct?

No - the directions are wrong. NTSC DV has 480 vertical
lines (determined by the number of vertical pixels and
the number of scan lines - but not all of these are visible).

>So regardless of the format, video is recorded in, the vertical
>resolution is always fixed, eg. for NTSC:
>
>mini-DV: horizontal resolution: 480 lines, vertical resolution: 525
>lines
>thus it is 525x480

NTSC, etc. vertical resolution is fixed, but the horizontal
resolution is not for analogue signals (though it is for
DV) - but these figures represent the MAXIMUM possible
resolution, not what you will get in reality...).

>VHS: horizontal resolution: 240 lines, vertical resolution: 525 lines
>thus it is 525x240

Well, 240x480 or so...

>Betacam SP: horizontal resolution: 700 lines, vertical resolution: 525
>lines
>thus it is 525x700

No, since "TV resolution" is figured differently from
source-image resolution, so "700" becomes about 500
for horizontal resolution...

>Why did I get the impression that mini-DV was 720x480 NTSC and 720x576
>PAL? Where are the numbers 525 and 625?

Probably the differences are in the spaces between frames...
And 720x480 is the NTSC source-image area H and V
pixel-count, not the actual resolution that winds up
being displayed...

>I assume the first number is always vertical resolution and the 2nd
>number is always horizontal resolution, is that correct? 720x480
>(HxV)

No - the first is horizontal resolution (of vertical
lines...;-); the second is vertical resolution (of
horizontal lines...;-). More confusing: people assume that
the figures for the format pixel array (DV) or medium
resolution limit is what they will get - but it cannot be.
These numbers (if accurate...) represent the ABSOLUTE
resolution limits, and only the very best gear can
*approach* these, but never "get there" - most gear shows
considerably lower resolution in practice...

>Can someone help me in layman's terms?

Prolly not...;-)
But, basically, there are two "systems" involved:
the "source-image" and the "display-image", and
these (and their resolutions) are not the same...