Re: [Phys-l] 240 and 600 Hz

["John Clement" <clement@hal-pc.org>]

120Hz is NOT a waste because it gets rid of the judder in telecined films.
Of course you could just have a monitor that can run at 24, 30, and 60, but
it is most probably cheaper to have one at 120 to be able to accommodate
both 30 and 24Hz.  However there is still a problem with converted PAL TV
shows which are at 25Hz.  However I suppose the 120Hz could allow for enough
interpolation so you would not have noticeable judder in 25Hz material.  The
next point would be 600Hz which could accommodate 24, 25,30, and 60Hz
material.

Wouldn't life have been simpler if they had adopted a 24Hz frame rate for TV
at the beginning?  But they used the line frequency for syncing.  Then when
color came in they lowered the frequency by a hair.  So the statinary
interference bars in B&W now became crawling bars.  The NTSC color frequency
was 29.97Hz, but this is close enough to 24 for most practical purposes.
DVDs are all made at the NTSC frame rate in the US, but I believe that
Blu-ray has actual 24Hz frame rate for movies.  My latest camera which does
3D movies has 720p 24Hz resolution and frame rate at 16:9 aspect ratio.

The best test is still to look at the screen and see if you can tell the
difference.  If not get the one you like that is cheapest.  Consumers claims
that 240 can look a hair better, but that may be due to other factors in the
design.  They also found that some 120Hz sets looked better than others at
240, so there are many factors which are probably much more important than
240 vs 120.

John M. Clement
Houston, TX

> There is a lot to be said for 72 Hz. With 60 Hz there are 
> sometimes trouble 
>  with synching with the line frequency
>  
> Alex. F. Burr  
>
>  
> In a message dated 4/18/2011 8:21:03 A.M. Mountain Daylight Time,  
> kowalskil@mail.montclair.edu writes:
>
> Because  of this I think that anything above 60 Hz is just waste of   
> money