What about this "scintillation" I am seeing????

Discussion in 'Archived Threads 2001-2004' started by Tony B, Nov 8, 2001.

  1. Tony B

    Tony B Auditioning

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    I am getting some good answers here so why not go for broke?
    I occasionally see, on bright objects again, these random and somewhat streaky white dots. It almost looks like the object is scintillating. Is it the signal from DishNet or is it a setting on my TV that is too high. Could it be this "Red Push"??? If not, what the hay is "Red Push"???
     
  2. Edwin-S

    Edwin-S Producer
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    Whatever the problem is it is not red push. From descriptions I have read the red push means that there is an overemphasis of red in the picture. People tend to look sunburned if the set is suffering from red push, this is due to a problem with the color decoder. A properly operating color decoder will be no more than roughly a 5% variance from a predetermined level of red. If the variance in the color red is greater than 5%, then the TV is considered to have a red push.
    Does the scintillation happen only when you are watching satellite or does it occur when you watch DVDs as well? If it is only with satellite, then it could be a signal problem. If it is happening with everything then the problem is probably in the set or in how you have the TV set up.
    [Edited last by Edwin-S on November 09, 2001 at 03:44 AM]
     
  3. Tony B

    Tony B Auditioning

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    Thus far I have only noticed it with the DishNet receiver. Is the bad signal going into the receiver from the SAT or is there possibly something wrong with the S-video signal going to the TV from the receiver?
     
  4. Edwin-S

    Edwin-S Producer
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    I haven't had a lot of experience with satellite services because I'm still hooked up to cable. There are more experienced people around here than I am when it comes to this hobby. You might want to check the board over at HomeTheaterSpot. There have been threads there covering some of the problems that people have had with DSS hookups.
    Some guys that posted there have found that some of their signal problems clear up by upgrading the cable that runs from the satellite dish into their set top box. I believe quite a few of them have had some luck using RG6 coaxial cable. There is also the possibility that the line doubler in your set could just be having trouble with the lower quality signal that comes off the satellite, resulting in artifacting.
    I would check over at HomeTheaterSpot and check to see if anyone else has had the same problem that you are describing.
     
  5. Allan Jayne

    Allan Jayne Cinematographer

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    High quality line doublers have a tendency to produce video pictures with scintillation, notably where dark and light patches meet. This is due to their normal switching between interpolating intervening scan lines and taking intervening scan line content from the next field (motion adaptiveness), and there can be dozens or even hundreds of back and forth changes during a single scan line. It occurs in different places on the next frame.
    The more noise in the original video material, the more scintillation will occur and also there will be softening of the picture.
    Some scintillation can be the result of MPEG compression on digital video. More commonly seen as a result of compression is a subtle crawliness in what should be a solid patch of color.
    Both of these effects should be almost unnoticeable if you are not sitting too close to the screen.
    More: http://members.aol.com/ajaynejr/viddoubl.htm
    [Edited last by Allan Jayne on November 10, 2001 at 08:22 AM]
     
  6. Steve Schaffer

    Steve Schaffer Producer

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    Tony,
    If you're seeing this effect in areas of solid color, a sort of tiny white dot with with a white trail going to the right with a sorta flickering effect, and it's only on Dish and only on certain channels, there's not a lot you can do about it. It's video noise which can be introduced into the picture at the source or anywhere else between the source and your display. If it's introduced into the picture before it reaches your receiver, either at the original broadcast source or at Dish's uplink, it has become part of the picture just like what you are intended to see, and all your equipment can do is reproduce it, not eliminate it.
    I get the same noise intermittently on some cable and satellite channels, but not others.
    ------------------
    Steve S.
    I prefer not to push the subwoofers until they're properly run in.
     

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