On Oct 24, 4:57 pm, "William Sommerwerck"
wrote:
"Sam Goldwasser" wrote in message

...

"William Sommerwerck" writes:
One possible source of moire patterns is the use of a 625-line tube
in a 525-line set, or vice-versa.
Huh? A 625line tube? Perhaps you should clarify.

This isn't a joke.

Think of the way a shadow mask has hundreds of thousands of tiny holes,
spaced at some particular pitch. Now imagine those whole "interfering" with
the scanning lines in the image, producing a moire.

I first learned of this about 25 years ago, when I viewed the then-new
Proton TVs. Proton was using CRTs with a dot-pitch suitable for a 625-line
system in 525-line TVs, to get better horizontal resolution. Unfortunately,
this sometimes produced moire patterns.

Wanna buy a bridge? How do you explain dual standard monitors? I
assure you I don't change out the CRT to change from PAL to NTSC. The
odds are much higher that the 'moire' is from the Y/C separation in
the monitor. If a DVD is played into the monitor/TV using _component_,
there would be no separation as the signal was never encoded. If the
moire is present then, THEN I'll buy CRT explanations.

GG