PAL & NTSC

Rudi H. Martinsen

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Jan 20, 1999, 3:00:00 AM1/20/99

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What's the difference ( what is PAL??)????

Wayne Jeffers

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Jan 23, 1999, 3:00:00 AM1/23/99

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PAL - Phase alternating line (or something like that)

NTSC - Never Twice the Same Colour

Gerald Coe

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Jan 23, 1999, 3:00:00 AM1/23/99

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In article <36A89835...@technologist.com>, Wayne Jeffers
<ea...@technologist.com> writes

SECAM - System Essentially Contrary to the American Method
PAL - Peace At Last

(:-)

Actually NTSC and PAL are essentially the same system, in that they both
have a luminance (B/W) signal and the colour encoded as two colour
difference signals. These are R-Y (Red subtracted from the luminance)
and B-Y. This is almost all the information needed to reconstruct the
image. G-Y is not transmitted, rather it is generated by adding
proportions of the R-Y and B-Y signals to produce -(G-Y) within the
receiver.
This is essentially the NTSC system. It has a problem in that the colour
difference signals are sensitive to phase variation during transmission.
The effect is very noticeable on skin colours, which is mainly the red
signal. To overcome this the PAL system alternates the phase of the R-Y
signal every line. This is summed with a 1 line delayed signal and phase
variations are cancelled out.

Ed Hall

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Jan 25, 1999, 3:00:00 AM1/25/99

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Rudi H. Martinsen wrote:
>
> What's the difference ( what is PAL??)????

Just to answer the question different to the other posts.

PAL, NTSC, (and SECAM for that matter) are standards for Television
Transmission. They are very similar with the main difference being in
the method of including the colour information (when colour TV first
started it was important that Black & White TVs stilled worked so
essentially the same old B&W signal was sent with additional colour
information).

PAL is the system used in Australia, NZ, UK, .....

Not USA, Canada, Japan, .... who use NTSC.

SECAM is mainly French.

A NTSC TV will not receive a PAL signal. A PAL TV will not receive a
NTSC signal. Note that their are multi-standard TV's and video's that
can handle both (useful if you get video tapes from the US), and also
videos that play a NTSC video tape into a PAL TV (ie, does a
conversion). Note that the older multistandard videos could play NTSC
tapes but did not convert - that is you needed a multistandard TV also.

As an aside, there are also different PAL standards. For instance, a TV
from the UK will not get sound when brought to Aus/NZ! Reason is a
difference in sound carrier spacing (radio signal stuff!). A video tape
recorded in the UK will play on a Aus/NZ machine as it records the base
video and sound signals.

Cheers,
Ed.
--
Ed Hall

The magician is the most honest of all professionals.
The magician first promises to deceive you, and then does so.

email: edh...@ihug.co.nz
http://homepages.ihug.co.nz/~edhall/
http://homepages.ihug.co.nz/~edhall/magic.htm