Bluray playback and 24 hz - juddering issues
Discussion
Hi all, I am aware from my research that LCD motion-handling is inferior to Plasma technology and I am aware of the limitations of my current Pioneer LCD.
What I don't understand is this - why when I play a DVD, upscaled on my PS3, panning and motion-handling appear to be better than when I play a bluray with all the optimum settings on (i.e. 24fps playback).
Is this an inherent problem with 24 fps? I have seen references to '24fps judder' in some TV reviews but not clear on what causes it and why.
Can anyone shed some light on Mr Confused?
It almost makes buying Blurays a false economy for me, even though it is the exact media I should be watching in awe on my full HD tv!
What I don't understand is this - why when I play a DVD, upscaled on my PS3, panning and motion-handling appear to be better than when I play a bluray with all the optimum settings on (i.e. 24fps playback).
Is this an inherent problem with 24 fps? I have seen references to '24fps judder' in some TV reviews but not clear on what causes it and why.
Can anyone shed some light on Mr Confused?
It almost makes buying Blurays a false economy for me, even though it is the exact media I should be watching in awe on my full HD tv!
This is kind of a rough explanation, loads more detailed explanations are online.
Movies are filmed at (near enough) 24fps as opposed to TV which is generally filmed at 50Hz or 60Hz. Standard TV's refresh at 50 or 60Hz so they can easily display TV images the problems come when displaying movies. In the olden days (video and DVD) the movies would be converted from 24fps to 25fps(50Hz) or 30fps(60Hz) by a high quality offline process before being written to video or DVD.
Bluray discs hold the raw 24fps images, and as the conversion to 50Hz is too dificult to do in real-time they are crudely converted to 60Hz (3:2 pulldown) which caused the horizontal judder. To eliminate the judder you need a bluray player capable of outputting the 24fps signal (as opposed to outputting a 3:2 pulldown'd 60Hz signal) and a TV not only capable of accepting the 24Hz signal but also displaying it, by refreshing the screen at a multiple of 24Hz (either 48Hz or more commonly 72Hz).
EDIT: one thing to add is that 24Hz is quite low so even when you go to the cinema you get some judder, especially on cgi generated landscapes (such as in the lord of the rings films), however judder is usually hidden by the motion blur on the camera. So even with full 24fps support you may still get a little judder. Also judder is more easily noticable on a larger screen (assuming the same viewing distance).
Movies are filmed at (near enough) 24fps as opposed to TV which is generally filmed at 50Hz or 60Hz. Standard TV's refresh at 50 or 60Hz so they can easily display TV images the problems come when displaying movies. In the olden days (video and DVD) the movies would be converted from 24fps to 25fps(50Hz) or 30fps(60Hz) by a high quality offline process before being written to video or DVD.
Bluray discs hold the raw 24fps images, and as the conversion to 50Hz is too dificult to do in real-time they are crudely converted to 60Hz (3:2 pulldown) which caused the horizontal judder. To eliminate the judder you need a bluray player capable of outputting the 24fps signal (as opposed to outputting a 3:2 pulldown'd 60Hz signal) and a TV not only capable of accepting the 24Hz signal but also displaying it, by refreshing the screen at a multiple of 24Hz (either 48Hz or more commonly 72Hz).
EDIT: one thing to add is that 24Hz is quite low so even when you go to the cinema you get some judder, especially on cgi generated landscapes (such as in the lord of the rings films), however judder is usually hidden by the motion blur on the camera. So even with full 24fps support you may still get a little judder. Also judder is more easily noticable on a larger screen (assuming the same viewing distance).
Edited by Mr_Yogi on Wednesday 2nd June 12:15
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