Home audio & video forum: 3:3 pull-down for real?

Well lets go back and talk about the 24fps movie and how you get it to 30fps video. It is done by scanning every 4th frame twice. So the movie frames would be scaned 1,2,3,4,4,5,6,7,8,8,9,10,11,12,12, etc. This will give you 30 tv frames by the time you get to 24 movie frames. and requires a special projector.
In the movie theatre what you are talking about is the flash or flicker rate that is used to project the movie in a theater. Ever heard movies refered to as the the flicks? To stop the flickering of movies EACH frame was double or tripple flashed on the screen by a rotating shutter in the projector, this flashing is what fools your eyes into "seeing" motion without flickering.
When you talk about video there is a difference between
regular TV and watching DVDs on a PC.
One TV frame is made up 2 fields of 262.5 interlaced scanlines so when both fields have been scaned the result is one frame of 525 scan lines. This is the NTSC
standard on a regular TV since 1946 or so.
DVDs played on a standard TV will follow the above format.
DVDs on a PC will be at full DVD resulion will be shown in a progressive scan format and show the full frame and not the overscaned frame as on a TV. HDTV monitor using component connections will also do this.

What you are talking about in computer video is similar but not the same. Many people complane about filcker in the computer monitors when the the virtical refersh rate is set to 60hz ( the MS default ) and the have florescent lighting in the office, I usualy "fix" this by setting the rate to 72hz. A higher refersh rate makes the picture look better, just as flashing the image on the screen 3 times does in the movies. John

Thanks for education! I wish the HDTV magazine and the manufacturers themselves provided as thorough an explanation.