In article <telecom24.49.11@telecom-digest.org>, Mark Crispin
<MRC@CAC.Washington.EDU> wrote:
> Arguably, European TV systems are "better" than system M by having 100
> more scan lines; but that too comes at a hefty cost; a 50Hz refresh
> rate that is noticably flickery. People who live in Europe for
> extended periods of time may no notice it; but Americans (and
> Europeans who had extended stays in North America do.
Of course people who are used to everything flickering at 60 Hz will
find things that flicker at 50 Hz irritating -- the converse is also
true! After nine months in 50-Hz territory, when I returned home I
found everything electrical unbearably flickery for a good three
months or so before my brain readjusted. It's not like the developers
of systems [A-LN] had any choice in the matter: the power grid
frequency was pretty well fixed before TV became a consumer product.
Running TV at 60 Hz when all the lights around you (and in the
studio!) are flickering at 50 Hz would be far worse.
> In South America, there is PAL-M which uses PAL color on system M;
Only in Brazil to the best of my knowledge. and there it appears to
have been a market-protection tactic. Other countries use either
NTSC-M or PAL-N, except in the Caribbean where French posessions use
SECAM-K and everyone else uses NTSC-M. (Presumably the French are
able to get away with their 8-MHz channels by being far enough away
from congested airwaves that it makes no matter.)
> These days, the NTSC vs. PAL debate has been supplanted by 8-VSB
> vs. COFDM -- rather silly since the modulation has no impact on image
> quality (unlike, say, 720p vs. 1080i).
Not silly at all, since the modulation has a significant impact on the
quality and convenience of home reception. The fact that only a tiny
minority of digital TV consumers in the US are getting it from
over-the-air 8-VSB broadcasts (as opposed to 64-QAM cable or DVB-S
satellite) is evidence of that.
--
-GAWollman
Garrett A. Wollman | As the Constitution endures, persons in every
wollman@csail.mit.edu | generation can invoke its principles in their own
Opinions not those | search for greater freedom.
of MIT or CSAIL. | - A. Kennedy, Lawrence v. Texas, 539 U.S. ___ (2003)
Garrett Wollman (wollman@lcs.mit.edu)