The system used in UK. Developed in Germany in the late 1960s. Used in the UK and much of Europe. Similar to the NTSC system that had been developed more than a decade earlier, the PAL signal has the phase reversed on alternate lines to improve colour stability. .
Phase Alternate Line is the acronym's expansion.
PAL has a line/frame rate of 625/25, which means that pictures are made up of 625 horizontal lines scanning at 25 frames per second

There are also two other PAL systems that are used in some South American countries

 

PAL-N is only used in Argentina, Uruguay and Paraguay. It is basically the same as normal PAL but with the sub-carrier is set at 3.58 MHz so that narrower channels can be used
PAL-M bears a greater similarity to NTSC than PAL. It is only used in Brazil. It is similar to PAL-N but has a 525/30* line/frame rate, the same as NTSC

The original colour television system. Developed in the United States and introduced in 1953 from a specification laid down by the National Television Standards Committee.
NTSC pictures are made up of 30* frames scanning at 525 horizontal lines per second.

Another interpretation is Never Twice the Same Colour, due to the signal's susceptibility to differential phase errors.

* The true frame rate for NTSC is in fact 29.97 frames per second (FPS). Working at 30 FPS results in an error of 3.6 seconds (108 frames) per hour between tape counters and real time. More sophisticated cameras, VCRs and editing equipment can compensate for this by having a "drop frame" (DF) mode. It doesn't actually drop a frame of video, but what happens is that the counter drops 2 frames every minute EXCEPT every 10th minute. Each time it drops frames you will see the frame time code go 28, 29, 02, 03. This brings the tape counter into line with real time.

Started in France in the late 1960s, and used by other countries with a political affiliation. Also adopted by the former Soviet Union and many Eastern Block countries to be intentionally incompatible with Western TV broadcasts. Since the fall of the "Iron Curtain", some of the Eastern European countries have now changed over to PAL.

SECAM stands for Systeme En Coleur Avec Memoire. It has the same 625/25 line/frame rate as PAL. Pictures are made up of 625 horizontal lines scanning at 25 frames per second

Also said to stand for System Essentially Contrary to the American Method.

 

 

Steven Abrams Video Productions

E-mail convert@video-pro.co.uk