1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

What are the 'usual' 100Hz artefacts?

Discussion in 'Televisions' started by fallenangle, Oct 21, 2005.

  1. fallenangle

    fallenangle
    Active Member

    Joined:
    Oct 19, 2005
    Messages:
    404
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Ratings:
    +23
    I keep on reading about 100Hz TV artefacts due to the digital processing but what exactly are these problems?

    A simple explanation of why they occur would be interesting too.

    Finally what's the largest size flicker free 50/60Hz widescreen worth looking at?
     
  2. Kalos Geros

    Kalos Geros
    Active Member

    Joined:
    Sep 4, 2005
    Messages:
    2,090
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    66
    Location:
    Croatia
    Ratings:
    +135
    There is no flicker free 50Hz TV AFAIK unless you refer to progressive scan TV but all of these are also 100Hz in interlaced mode and 50Hz in progressive where you are most likely to experience large-area flicker but not interlace flicker...the symptoms of 100Hz artifacts these days (after they have mostly finally removed jittery motion) is blooming picture (like when you use median filter in Photoshop)...I believe it has something to do with the way or quality of buffering the fileld into digital framestore and an attempt to digitally remove the noise on bad sources (RF, composite, S-video even) becuase these come into the telly with bad artifacts already - mostly on edges - like dot crawl, color crosstalk, ghosting etc...some better sets have ways of disabling these filters...but RF will always look like sh.. - if a good RGB or component source is used like DVD or freeview DVB-T box the filters shouldn't be enabled (I think the set knows/autodetects composte or RF and switches the filters on for these connections, and off for RGB/component)
     
  3. fallenangle

    fallenangle
    Active Member

    Joined:
    Oct 19, 2005
    Messages:
    404
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Ratings:
    +23
    I asked about this because I'm not happy with the results I get when playing certain videogames (via decent RGB SCART) using my 32" 100Hz Sony widescreen CRT.

    I get what looks like motion blur (smearing?) when panning the in game camera around a scene. It happens with both PS2 and XBox games and only with this particular TV ie. not with my cheap as chips 50/60Hz 28" Bush widescreen/28" 4:3 Sharp/ancient 20" 4:3 Grundig.

    I'm also suffering horrible colour blocking and trailing effects in the shadows unless the brightness is set to unplayably low levels.

    I was just wondering if this is just to do with the particular TV or to do with these 100Hz artifacts.
     
  4. Cynthia 7

    Cynthia 7
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Hi fallenangle,

    Kalos has given you a wonderfully detailed explanation.

    For the last 15 years I have had 100Hz televisions, which have been top of the range models so possibly handle this better. The picture, to my mind, is outstanding and I have never noticed any drawbacks whatsoever. For motion blur, which occurs sometimes around a ball travelling through the air, i.e. cricket, football, my tv has Pixel Plus modes to reduce this. My husband has never even noticed it!

    We do have two other 50Hz televisions, and I now find the picture trying to my eyes if I watch for long, even when connected to a rooftop aerial. It must be because for so long I have watched a flicker free picture. There are a few members who still are pro 50Hz, possibly because it gives a natural picture. So often people leave their television settings as they left the factory but when you have tweaked them to your satisfaction the picture looks natural, yet stunning. I visited an elderly friend a year ago and could hardly bear to look at her television. It was just as it was from the factory. The contrast and brightness were on maximum setting, which also wears out the tube. She said she didn't watch much television as it hurt her eyes (she watches it from 4 feet away! I spent some time altering her settings until she had a natural looking picture, now she watches tv nearly all day. Maybe I didn't do her a favour!

    I have a year old Philips 36" screen, not available now, and if your finances and space are o.k. try to get at least a 32" tv. It gives you the feeling that you are almost into the programme you are watching. I watch from 11 feet because it's where my sofa is positioned. Certainly you should be at least six feet away.

    It sounds as if you are contemplating buying a new set. Places like Currys and Comet usually show DVDs on the screen so the picture looks good, which is not a true picture of how it would be with a terrestial aerial or Sky. I hope you find your perfect television.
     
  5. Kalos Geros

    Kalos Geros
    Active Member

    Joined:
    Sep 4, 2005
    Messages:
    2,090
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    66
    Location:
    Croatia
    Ratings:
    +135
    Then your TV may be doing a-not-very-good motion interpolation to get 100 discreete fields per second or the game is progressive at low framerate like 25 fps which can result in motion-blur-like effect since 25 fps is too low to look smooth on fast motion...there is also this explanation: maybe your TV knows about the latter problem and tries to rectify this by smearing the motion which partially eliminates the 25fps judder...it would be best if you posted the pictures oy your screen with the mentioned smearing...in the mean time try turning off all the picture enhancements your TV supports if possible....
     
  6. fallenangle

    fallenangle
    Active Member

    Joined:
    Oct 19, 2005
    Messages:
    404
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Ratings:
    +23
    Turning off all picture enhancements was the first thing I did but to no effect.

    Using a TV for video games is a fairly specialised area and otherwise I've no problems with the set. On analogue/digital broadcasts it's absolutely fine. But with any games console connected through RGB SCART that's when I'm getting (or noticing) the problems mentioned.

    The smearing/motion effect occurs with games a diverse as Soul Reaver 2(PS2), GTA: Vice City (XBox) and Myst IV (NTSC XBox). I suspect that if I hadn't played these games on other TVs I wouldn't know this wasn't normal.

    In fact on it's own it's not a huge problem I just wish it wasn't there. But when combined with the dark area trailing/blocking it can make some games hugely unpleasant to watch and difficult to play.
     
  7. Caprylate

    Caprylate
    Active Member

    Joined:
    Aug 1, 2005
    Messages:
    84
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    8
    Ratings:
    +3
    I have a 100Hz Toshiba TV (32ZH46S), in my DVD player settings, is it better to choose Pal 50 or Pal 60? I was thinking Pal 50 as it would be just a simple doubleing, but 60Hz might be better on 100Hz TV's because its closer to 100Hz. What option should I choose. Bear in mind, I cannot turn 100Hz mode off.
     
  8. fallenangle

    fallenangle
    Active Member

    Joined:
    Oct 19, 2005
    Messages:
    404
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Ratings:
    +23
    I would guess you're always better off going for the higher rate. I don't know about DVDs but using any 60Hz options makes games play smoother and faster. It used to be one of the prime reasons for importing NTSC games.

    But as I understand it the point about these 100Hz TVs is that whatever speed you select they still digitally process the image in the same way. In other words any 'artifacts' are going appear what ever settings you use.

    BTW I meant to thank people here for their earlier replies.
     
  9. Kalos Geros

    Kalos Geros
    Active Member

    Joined:
    Sep 4, 2005
    Messages:
    2,090
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    66
    Location:
    Croatia
    Ratings:
    +135
    It doesn't matter, PAL 60 is in effect only with NTSC source and effects only S-video and composite, not RGB SCART or component...it was designed to play NTSC content on TVs that cannot decode NTSC color coding but are multiscan...such TVs don't exist for at least 10 years now so don't bother, you will not get 60 Hz froma a PAL 50 Hz DVD, sorry...also your logic is wrong - 100 Hz is a perfect multiplier of 50 Hz, a perfect match for NTSC 60 Hz iz - you guessed it - 120Hz, which no CRT TV does AFAIK...So NTSC will run in 60 Hz on your TV...PAL will run at 100Hz...
     

Share This Page

Loading...