PAL and NTSC on DVDs

[Roy G. Ovrebo]

On Tue, Dec 9, 2008 at 9:23 PM, Keith Henderson <khenders64 at yahoo.com> wrote:
> J.C. wrote...
>
>> >> anyway, the PAL thing only applies to videos, not
>> dvd's doesn't it?
>>
>> No, it applies to DVDs as well.
>>
>> This is a subject with a lot of piece-parts, and I'm
>> sure I do not understand
>> it fully, but here's a summary. Corrections and/or
>> pointers to a better article welcome.
>
> I'm just a layperson on this subject as well, but my understanding is that the difference in all "video" (ie, scanned images displayed on rows of pixels on a screen) between No.Amer./Japan (NTSC) and Europe/rest of world (PAL) reflects very basic differences that cannot be changed with any new format.  Conversion is the only way.  And that basic difference is in part due to the difference in electrical power, *not* the voltage difference but rather the frequency, 50 Hz vs. 60 Hz.  Because the scan rate is set to match the frequency of the alternating current in order to avoid weird interference patterns on your screen.

I think that isn't a problem anymore. TV system frequency doesn't have
to be wedded to the power frequency.

[snip]

>> It turns out that
>> up-converting NTSC to PAL is
>> so easy that most DVD players in the UK include this
>> feature. Going the other way is
>> harder (I don't know why) or perhaps just rarer.
>
> Maybe it is because NTSC has extra images (5 more) per second that can just be thrown out (or rather, a half-image of the odd-row of Image No. 3-NTSC mixed with a half-image of the even-row of Image No. 4-NTSC to make Image No. 3-PAL, whereas 1,2,5 and 6 NTSC are all taken straight across as images 1,2,4, and 5 PAL.  Repeat until 25 images are made from the original 30.)  ...is the way I think it actually goes.  This happens five times a second, so your eye wouldn't actually see this overlapping of half-images, unless Jerry Bruckheimer was director and the images only routinely last 0.2 seconds between cuts.

Wikipedia: "Many newer VCR and DVD players sold in Europe can play
back NTSC tapes/discs. When operating in this mode most of them do not
output a true (625/25) PAL signal but rather a hybrid of PAL and NTSC
known as "PAL 60" (or "pseudo PAL") with "60" standing for 60 Hz,
instead of 50 Hz. Some video game consoles also output a signal in
this mode. Most newer television sets can display such a signal
correctly but some will only do so (if at all) in black and white
and/or with flickering/foldover at the bottom of the picture, or
picture rolling"

My personal experience: Most DVD players now will convert the colours
of this PAL 60. Most TVs now will get the colours right without
depending on the DVD player.

I've got an old TV. When playing an NTSC disc on one DVD player, it'll
display in black'n'white, because neither the DVD player nor the TV
set will handle the converted colours right. Plug that DVD player into
a more modern TV and I'll get colour. I've also got another DVD player
that'll show NTSC discs in colour on the old TV.

So if your DVD player _and_ TV aren't _both_ crap, you should be able
to play NTSC discs in colour...

-- 
Roy