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The Great Debate – NTSC HD vs. PAL HD

Technically, the title of this article is incorrect, since NTSC and PAL refer to standard-definition video formats. Nevertheless, you may see these terms come up in the various places, so please read on and it will soon make sense.

As HD video was first gaining momentum a few years back, many videographers were excited that we might finally be able to have a worldwide video standard that would eliminate the incompatibility issues between the NTSC and PAL video formats used in different countries.

In case you’re not familiar with the differences between NTSC and PAL, here’s a short history here. In the U.S., the standard-definition video broadcast standard has always been NTSC, which uses 525 lines of video at 29.97 fps (frames per second). In the digital world of the NTSC DV format, popular in camcorders and computer editing applications, 720×480 pixels are used to create a frame of video.

PAL video, used in the UK and many other countries, is a 625-line format at 25 fps. PAL DV uses a 720×576 frame size, somewhat larger than the 720×480 of NTSC DV. So, not only is the video frame a different size, but the frame rates differ as well with 25 for PAL vs. 29.97 for NTSC!When video editors need to combine NTSC and PAL footage for various reasons, there must be a format conversion to account for the differences in both frame size and frame rate. It’s more than a minor inconvenience, to put it mildly, and most video professionals would love to see these differences go away.

As mentioned earlier, HD video was supposed to eliminate the incompatibility between videos from different countries, since the same frame sizes are used worldwide. For instance, full 1080 HD is 1920×1080 pixels, 1080 HDV uses 1440×1080 pixels, and 720p uses 1280×720 pixels in any country.

The problem that arises is that many HD formats still have different frame rates between NTSC and PAL countries. While HD has unified the frame sizes, we are still stuck with “PAL” HD using 25 fps while “NTSC” HD uses 29.97 fps.

With interlaced video formats, each frame of video is actually made up of two fields, meaning PAL video has 50 fields and NTSC has 60. This correlates to the electrical systems used in PAL and NTSC countries, which operate at 50Hz and 60Hz respectively – in other words, the video equipment gets its timing from the power source.

Even though progressive-scan video uses only frames and not fields, we can still feel the effects of PAL vs. NTSC when looking at 720p video – 720p30 runs at 29.97 fps and is used in countries with NTSC, while PAL users shooting 720p will have 720p25 at 25fps! It seems that the only “universal formats” may be 1080p24 and 720p24, as these will be 24 fps in any country. Note that 24 fps is also the speed of movie film, which may be behind the universal appeal of 24p video.

From now on, if you see “PAL” associated with an HD format, it means it uses 25 fps, while NTSC would mean 29.97 fps. While not really correct, these labels continue to be used, but at least you’ll understand the reference when it comes up.

So as not to perpetuate the erroneous PAL and NTSC labels as you move into HD production, you should be familiar with proper HD format labels. While the exact syntax may vary from place to place, a typical designation of “1080i30” would equate to 1080 interlaced video at 29.97 fps and “720p24” would be 720 progressive at 24 fps. You will do well to forget about PAL and NTSC labels and pay close attention to frame rates when shooting and editing HD video.

Many HD cameras offer multiple frames rates, and some even offer both 1080 and 720 recording capabilities, so be very careful when setting up the camera for a shoot, whether for yourself or when providing footage for another company. If you choose the incorrect format, it could turn into a hassle as the footage may require conversion which takes time and could also reduce the quality.

1 comments
Notmine
Notmine

Thanks for the article. Really clear and useful.

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The Great Debate – NTSC HD vs. PAL HD