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29.97 vs 30 f.p.s.

Posted: Sat Jun 13, 2009 7:17 pm
by RayBaker
Can someone please explain to me the difference between 29.97 & 30 fps?

Does it make much difference?

And is one better than the other?

Thanks...

Posted: Sat Jun 13, 2009 8:44 pm
by Ron P.
About .03 fps...;)

The difference is the target media. For Standard Def Video DVDs, (NTSC) it must be 29.97 to meet the DVD specs. If your video is intended for computer/internet viewing, it does not really matter..

Posted: Sun Jun 14, 2009 1:02 am
by RayBaker
vidoman wrote:About .03 fps...;)

The difference is the target media. For Standard Def Video DVDs, (NTSC) it must be 29.97 to meet the DVD specs. If your video is intended for computer/internet viewing, it does not really matter..
thanks again vidoman...

I did not know that...

Posted: Sun Jun 14, 2009 1:37 am
by Ken Berry
A somewhat more geeky answer is that as long ago as 1940, when the US National Television System Committee (NTSC) was established, the standards for black and white TV were adopted (varying an earlier 1936 standard). The new standard included an interlaced frame speed of 30 fps.

In 1950, the Committee started looking at the broadcasting standard for colour TV which was finally approved in December 1953. While this new standard was fully backward compatible with existing black-and-white TV sets, they had to add extra colour information and this was done by adding a color subcarrier of 4.5 ¡Ñ 455/572 MHz (approximately 3.58 MHz) to the video signal. To reduce interference between the chrominance signal and FM sound carrier required a slight reduction of the frame rate from 30 frames per second to 30/1.001 (very close to 29.97) frames per second, and changing the line frequency from 15,750 Hz to 15,734.26 Hz. And that is the official explanation for that slight variation between the two speeds!!! :lol: :lol: :wink:

Posted: Sun Jun 14, 2009 12:04 pm
by mitchell65
Please! Please! do not tell us that you had all this info inyour head :( :o

Posted: Sun Jun 14, 2009 9:30 pm
by Black Lab
Of course not. Ken reads Techno Geek Weekly for pleasure. :wink: