50hz or 75hz

Discussion in 'Desktop & Laptop Computers Forum' started by fallwood, Mar 11, 2006.

  1. fallwood

    fallwood
    Active Member

    Joined:
    Sep 10, 2004
    Messages:
    864
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Leeds
    Ratings:
    +6
    Does it make any difference if I run at 75hz rather than 50hz. I have my htpc connected to my z4 via hdmi which will take both 50 and 75hz but tmy plasma connected by vga will only take 75hz ( a restriction of the catalyst drivers over vga), I need to be able to turn either display on and not have to mess about with the hz settings. 75hz seems to be working ok for both but I just wondered if there are any downsides to running at 75hz.

    Thanks.
     
  2. MikeTV

    MikeTV
    Well-known Member

    Joined:
    Feb 1, 2003
    Messages:
    7,782
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Ealing, London
    Ratings:
    +842
    I can't think of any downside to running at a higher refresh rate. Both rates are multiples of 25Hz, which is ideal for PAL based video material, and the extra frequency will help with 60Hz material too.
     
  3. stlic

    stlic
    Active Member

    Joined:
    Feb 17, 2004
    Messages:
    769
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +19
    I believe it changes form display to display in some case a lower Hx setting will give a sharper image with obviously more flicker being the downside. If you personally can't notice a difference then there probbaly isn't a percievable one.
     
  4. Catsmeat

    Catsmeat
    Active Member

    Joined:
    Dec 29, 2005
    Messages:
    102
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Location:
    Greater Manchester
    Ratings:
    +3
    My plasma takes 50Hz or 75Hz over VGA. The only difference I can see is that 50Hz flickers. I'm sticking with 75Hz :smashin:
     
  5. boez

    boez
    Active Member

    Joined:
    Feb 21, 2005
    Messages:
    352
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    28
    Ratings:
    +34
    No - viewing 60Hz source material on 75Hz display will lead to frame rate conversion judder.

    For 50Hz source material (PAL) stick to 50Hz if possible or else 75Hz.
    For 60Hz source material (NTSC) you will need to set your display at 60Hz.

    HTH
    Boez
     
  6. stlic

    stlic
    Active Member

    Joined:
    Feb 17, 2004
    Messages:
    769
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +19
    The original statement was incorrect but if you are watching VIDEO NTSC then 60Hz is ideal as it is a multiple of 30 fps. For ~24 fps FILM NTSC (most movie DVDs) 60 Hz means frames are repeated at a variable multiple so no silky smooth panning. In this case, depending again on how much it all bothers you, speeding up ~24 to 25 fps and outputting to a 75 Hz display may be the ideal solution. If your display is capable of 48 or 72 Hz your in luck.
     
  7. dogtanian38

    dogtanian38
    Standard Member

    Joined:
    Oct 18, 2004
    Messages:
    60
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    6
    Ratings:
    +0
    Out of interest is there a hd plasma/projector that can handle 48,50,60 and 72 Hz natively, and accept those via dvi/hdmi at 1:1 pixel ratio from a PC?
     
  8. boez

    boez
    Active Member

    Joined:
    Feb 21, 2005
    Messages:
    352
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    28
    Ratings:
    +34
    Not sure about a HD plasma but my SD Panasonic PWD8 can handle 48, 50, 60 and 72Hz at a 1:1 pixel mapping :thumbsup:

    Takes a bit of messing with Powerstrip and its usefull that the Panny will tell you what the value of the input signal frequency is.



    HTH
    Boez
     
  9. joffonon

    joffonon
    Active Member

    Joined:
    Dec 4, 2002
    Messages:
    163
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    Westcliff-on-Sea, Great Britain
    Ratings:
    +25
    It can't do 72Hz, but my Panasonic AE700 LCD projector can do 48, 50 and 60Hz natively. Like boez, I find it takes a bit of fiddling with Powerstrip, but it's worth it.
     

Share This Page

Loading...