Converting the GeoVISIONTM NTSC Signal to PAL or SECAM
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PAL, NTSC, and SECAM Explained
NTSC (National Television System Committee) is the video standard used
in many countries around the world and for Marks Products GeoVisionTM
Camera systems. NTSC was the system adopted in the 1950s as
American television manufacturers prepared for the changeover from black &
white to color television. The primary philosophy behind the NTSC system was - to make sure that color
broadcasts wouldn't look garbled on the black & white TVs predominantly
used at the time, NTSC is
used in North and South America (excluding Brazil), and many parts of the Far
East. While it's not technically superior, it's more widely used because
it is used in the United States
and Japan. When
a VHS, DVD or laserdisc is released using
the NTSC format it can have a maximum
resolution up to 525 lines with a vertical frequency of 60hz.
PAL (Phase Alternating Line) is a video standard used in Western Europe (excluding France), Australia, some parts of Africa and a few regions of the Far East.
When a VHS, DVD or
laserdisc is released using the PAL format it can
have a maximum resolution up to 625 lines with a vertical frequency of 50Hz.
There are different types of PAL standards, one of which uses a vertical frequency of 60Hz
instead of 50Hz. PAL is an encoding scheme that allows for sharp pictures and color.
SECAM (Sequentiel
Couleur Avec Memoire)
The SECAM standard is used in France and eastern Europe, much of the Middle East, and some parts of Africa and the Caribbean
So can you play a PAL
VHS, DVD or laserdisc on an NTSC
TV? The answer is no. TVs are either NTSC
capable, PAL capable or both. Nearly every TV in the United States is NTSC only. If you live in a country where PAL is
the standard, you can generally get a TV that is capable of both PAL and
NTSC native playback.
So you live in an NTSC
country and you want to play a PAL Video tape or DVD, what's are the options? Look at the possible solutions and
the good and bad of each.
|
Solution
|
Good
|
Bad
|
|
Buy a NTSC / PAL TV or VCR Allows native
playback of both NTSC and PAL standards.
|
Native playback of both signals
|
Expensive - Have to import it (high shipping + taxes).
Power converter needed.
|
|
Buy a NTSC / PAL Converter - Converts PAL to NTSC
format, allowing for playback on NTSC TV (or vice versa)
|
High quality conversion if you get a good model.
|
May cost more, good equipment starts at approximately
$200.
|
|
DVD decoder card - Many have PAL / NTSC conversion
capability
|
Inexpensive
|
Quality isn't as good as the other solutions,
|
Format Standards by Nation
The following link provides a list of countries listed by
video format used.
World Television Conversion Standards
For a more detailed explanation on video format
conservation standards go to:
Building Bridges
between the Standards
For GeoVISIONTM
product information, sales, brochures, demo tapes, and pricing on all of our
products you may:
Call 800-255-1353 toll free
from the US and
Canada, elsewhere
804-741-4274
Fax
1-866-871-9646 or
Email: john@geovision.org