CCTV system PAL VS. NTSC
Source: LS VISION
Date: 2016/10/21
Different countries has different format, like normal we say PAL and NTSC.
That means PAL and NTSC use interlaced frames even lines － on one frame and odd lines － on the next frame. Interlacing frames gives a smoother motion with half the frame rate, the downside is with scene changes. NTSC is used with a fps of 60i or 30p whereas PAL generally uses 50i or 25p; both use a high enough frame rate to give the illusion of fluid motion. This is due to the fact that NTSC is generally used in countries with a utility frequency of 60 Hz and PAL in countries with 50 Hz, although there are many exceptions. PAL has a closer frame rate to that of film and is less likely to suffer from issues caused during frame rate conversion. Artefacts caused by frame rate conversion required when video has been recorded at the wrong rate for the display can be severe.
NTSC receivers have a tint control to perform colour correction manually. If this is not adjusted correctly, the colours may be faulty. The PAL standard automatically cancels hue errors by phase reversal, so a tint control is unnecessary. Chrominance phase errors in the PAL system are cancelled out using a 1H delay line resulting in lower saturation, which is much less noticeable to the eye than NTSC hue errors.
However, differt format present different image—can lead to picture grain on pictures with extreme phase errors even in PAL systems, if decoder circuits are misaligned or use the simplified decoders of early designs (typically to overcome royalty restrictions), if format not correct, image may not apprear. Finally, we can adjust the format when using.
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