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Re: Has the way the 4:3 flag is broadcast been changed?

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NY <me@privacy.net> wrote in news:118j9l8$18lvp$1@dont-email.me:

>> The effective resolution left is 540x576. That is absolutely adequate
>> for SD. 720 pixel columns is higher resolution than analogue PAL ever
>> was.
> 
> Is it? I thought that 720 was chosen specifically (*) to be about 4/3 of 
> the number of rows (576),

4:3 would be exactly 768x576, and that is a format actually used in 
some editing systems. But this an idealistic value that was never 
achieved in the analogue era. Even 720 wasn't.

> Given that almost every TV nowadays uses a non-CRT display, so the whole 
> screen is illuminated for the whole frame, interlaced or progressive is 
> fairly irrelevant: it's a difference only of delivery, rather than of 
> display.

Yeah but if the original content never had 720 pixels per line to begin 
with, it doesn't matter if they throw away part of it by cropping the 
sides. And it doesn't:
 
> (*) In the same way that the analogue bandwidth was limited to about 5.5 
> MHz which limits horizontal resolution. 5.5*10^6 / (625*25) = 352, which 
> is 352 pairs of alternate black/white pixels, so 704 pixels in total. 

Yes absolutely, but you're forgetting something: The sync pulse took up 
about 20 percent of each line, leaving roughly 282 cycles, which 
applying Nyquist requires 564 pixels.

So if they broadcast an analogue era video production at 720x576 
widescreen and black side panels cropped to 540 pixels, you are still 
getting the full resolution of that videotape, or at least close enough.

-- 
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Has the way the 4:3 flag is broadcast been changed? "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-07 21:28 +0100
  Re: Has the way the 4:3 flag is broadcast been changed? NY <me@privacy.net> - 2026-09-13 21:11 +0100
    Re: Has the way the 4:3 flag is broadcast been changed? "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-13 22:39 +0100
    Re: Has the way the 4:3 flag is broadcast been changed? Brian Gregory <void-invalid-dead-dontuse@email.invalid> - 2026-09-13 23:39 +0100
      Re: Has the way the 4:3 flag is broadcast been changed? "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-14 03:12 +0100
        Re: Has the way the 4:3 flag is broadcast been changed? Brian Gregory <void-invalid-dead-dontuse@email.invalid> - 2026-09-18 22:50 +0100
          Re: Has the way the 4:3 flag is broadcast been changed? "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-19 00:36 +0100
        Re: Has the way the 4:3 flag is broadcast been changed? Brian Gregory <void-invalid-dead-dontuse@email.invalid> - 2026-09-18 22:57 +0100
          Re: Has the way the 4:3 flag is broadcast been changed? "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-19 00:38 +0100
            Re: Has the way the 4:3 flag is broadcast been changed? Brian Gregory <void-invalid-dead-dontuse@email.invalid> - 2026-09-19 05:03 +0100
              Re: Has the way the 4:3 flag is broadcast been changed? "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-19 22:01 +0100
    Re: Has the way the 4:3 flag is broadcast been changed? richard@cogsci.ed.ac.uk (Richard Tobin) - 2026-09-14 09:55 +0000
      Re: Has the way the 4:3 flag is broadcast been changed? NY <me@privacy.net> - 2026-09-14 14:37 +0100
        Re: Has the way the 4:3 flag is broadcast been changed? "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-14 19:15 +0100
    Re: Has the way the 4:3 flag is broadcast been changed? wolfgang s <see@sig.nature> - 2026-09-18 09:19 +0000
      Re: Has the way the 4:3 flag is broadcast been changed? NY <me@privacy.net> - 2026-09-18 13:09 +0100
        Re: Has the way the 4:3 flag is broadcast been changed? "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-18 22:13 +0100
        Re: Has the way the 4:3 flag is broadcast been changed? Brian Gregory <void-invalid-dead-dontuse@email.invalid> - 2026-09-18 22:42 +0100
        Re: Has the way the 4:3 flag is broadcast been changed? wolfgang s <see@sig.nature> - 2026-09-20 19:03 +0000

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