NTSC and PAL are two different video standards, that decide how a video signal is displayed or rendered on analog video systems. Due to incompatibility of these standards, a DVD encoded in NTSC format, won't be rendered properly by an analog video system, that is built for PAL format. That is why, American NTSC format videos won't be rendered properly on European television sets and vice versa.
One may wonder why does the difference between two analog video formats matter in this age of digital TV and HDTV. There is one prime reason for this, which is the following. Even though the signals are digitally modulated, their rendering on television sets and computer screens is still analog. So, frame rate and pixels displayed per second, which are defined by these standards, still make a difference.
Any video is actually a display of rapidly changing series of still images, displayed in succession. The rate of change of each picture frame is so high, that our eyes do not notice the discontinuity between the images. On a TV screen, there are two ways in which pictures are rendered. One is the interlacing method and other is a progressive method.
In both methods, every frame is divided into lines. In the interlacing method, alternate sets of odd and even lines are displayed in succession, while in the progressive method, each line is numerically rendered on-screen. More the lines of display on-screen, more is the resolution and clarity of the moving picture. Two important parameters are the frame rate (still images displayed per second) and the resolution (number of lines in each frame). After this brief background, let me begin with the comparison.
Fundamental Difference Between NTSC and PAL
NTSC stands for 'National Television System Committee', which was instrumental in developing it as a TV broadcasting video format. First developed in 1941 in USA, it was modified in 1953 for color television. In 2009, it was replaced by the ATSC (Advanced Television Systems Committee) format, as the default standard for over-the-air television signal transmission.
PAL (Phase Alternating Line) was introduced as an analog television encoding system in 1963 and was invented by Walter Bruch at Telefunken, a German television company. It is used throughout most of Europe and Asia as the default analog television video standard. Let us see the difference between the two video standards, according to region of usage, frame rate, and resolution.
NTSC as a format for transmission and display of video images is used in Canada, Japan, Mexico, Korea, Peru, Panama, Nicaragua, Panama, Philippines, Cuba, and until very recently, USA. Compared to NTSC, PAL has a wider worldwide acceptance. It is used in Germany, United Kingdom, Switzerland, Australia, India, Denmark, Finland, Brazil, Indonesia, China, and many other countries around the world.
Difference in Frame Rate
Due to the frequency of alternating current delivered in United States of America being 60 Hz, NTSC-based signals are rendered at a rate of 60 fields per second. Due to the interlacing nature of rendering method on a television, this means that an NTSC based television has a frame rate of 30 per second.
On the other hand, the countries which have electrical power delivered at 50 Hz, have a PAL frame rate of only 25 frames per second. This is because, the moving picture in the PAL format is delivered at the rate of fifty fields per second.
Difference in Resolution
The picture quality is dependent on the resolution and frame rate. Resolution is quantified in terms of number of lines delivered in each frame. A PAL-based system, delivers 625 lines of resolution, compared to only 525 lines, delivered by NTSC. Color quality is much better in PAL-based systems, as compared to NTSC.
Be aware that an NTSC format DVD won't play on a PAL-compatible DVD player and vice versa, because of the mutual difference between the two formats. Some companies offer the facility for interconversion between the two, but it can be time-consuming. Just see to it that you take care of these analog video format differences, when sending video files to European or Asian countries, as they use PAL format. When purchasing DVDs, do not forget to check which analog video encoding format it has and see to it that your DVD player and television are compatible with it.