On Fri, 28 Dec 2001 19:25:53 GMT, "Brian C. Barnes" wrote:
>"Neuman - Ruether" wrote in message
>news:3c3194ae.4334126@newsstand.cit.cornell.edu...
>> On Fri, 28 Dec 2001 02:11:54 GMT, "Brian C. Barnes"
>> wrote:

>> >Keep in mind that the 640 x 480 in the computer uses square pixels, while
>> >the 720 x 480 NTSC uses a pixel aspect ration of approx. 0.90 to one,
>which,
>> >on a square pixel system (such as a computer screen), would look like
>about
>> >655 x 480

>> ???????????????
>> 720x480 with square pixels (what else, unless the viewing
>> system is specifically designed to correct this to 4:3...)
>> would look like 720x480 on a square pixel system...;-)

>What I meant was that the 720 x 480 NTSC DV standard is designed for 0.909
>pixel aspect ratio. When viewed on a TV, it looks normal. When viewed on a
>computer with square pixels, it should look a bit stretched in the X axis.
>If you import computer images into a video designed for 720 x 480 NTSC DV,
>the images should be about 655 x 480 square pixels in resolution, and would
>then "stretch" to the correct 720 x 480.

No, there are no "pixels" in TV - it is an analogue system,
with a bandwidth... The "720" is used to increase
resolution. The DV standard is 720, but it could be 800,
2,456,738, or whatever number (to adjust resolution), which
when converted back to analogue, becomes more (or less)
bandwidth to provide actual picture in 4:3 proportion.
If you import a graphic into a computer NLE, it should
be at 4:3 also (conveniently 640x480), to avoid
distortion - but it could be anything else in the same
proportion (I often use 1280x960) and still work in many
NLEs. The "655" number has no basis...