Video Asylum

Posted by SysInfo on November 07, 2003 at 20:49:35

In Reply to: PAL transfers speed increased from film´s original? posted by Joaquin on October 29, 2003 at 13:59:48:

It is all in the way how real film is projested and how TV samples signals.
If real film is projected 24fps, and PAL has 50 half-frames/s, then you are just fine as long as TV f/s is bigger than real film/s.
How is this?
Film presents one picture for certain amount of time and then switches to another picture, and cycle goes on. So you get a continious movement.
TV is sampled different. One picture is sampled continiuously for certain amount of time, and the another picture comes continuously again.
Film samples picture by picture in separate times, while TV samples continiously picture by picture without separation. There is blank pulse (signal) betwean TV pictures but that is way shorter than film.
So what happens ?
You DO NOT sync fps to PAL's half pic by increasing the speed, where did you get this crazy idea?
You just lose 4% of any 50-th picture or you lose (24/25)/2 of any single frame from the film.
You lose the same on NTSC + resolution that is worse.
Pitch is not altered AT ALL.Movie that is 1h on film will last 1h on PAL and NTSC as well.
Audio is not altered, and it is same for PAL and NTSC.
Although 1h video tape for PAL is longer than 1h for NTSC. But that's another story.