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Jagged edges on fast moving objects

Discussion in 'Projectors, Screens & Video Processors' started by Mr_Belowski, Mar 26, 2003.

  1. Mr_Belowski

    Mr_Belowski
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    Hi Peeps :)

    I was wondering if any of you clever folks could shed some light on a little issue I'm having with my (otherwise quite fantastic) Sanyo Z1.


    When objects in a scene move quickly horizontally, edges which are at an angle (i.e. not vertical or horizontal) are a little jagged - rather than being a smooth line, they're made up of lots of little zig-zags.

    I don't see any solid black horizontal lines or other artefacts - it's just these jagged edges, and it's only noticable on objects with high contrast edges.

    Are these caused by the de-interlacer? I'm currently using an interlaced S-video output from my DVD player. Will a progressive scan input remove this artefact? Does anyone else get this? Is it unique to the Z1, or a common LCD problem?

    Thanks in advance
     
  2. LV426

    LV426
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    My guess is that the scaler in the PJ, whilst able to interpolate (and hence scale, properly) fairly static images, can't keep up with lots of movement. So what you are seeing is the 'raw' image structure of the incoming signal - horizontal scan lines.
     
  3. Anders_UK

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    Sounds very much like pixel smear, unfortunately this is a inherent problem in any LCD projector. We suffer from it in fast jet simulators where you get the smearing of objects such as trees and houses as you fly past.

    The plus for us is that we have some anti-smear electronics, the bad side for you is that you are going to have to live with it.

    To limit this problem try and make sure your input source is as closely matched to your panel size as possible, and have the anti-aliasing function checked. Unfortunatley the LCD crystals can't flip as fast as you would like so some cross talk is bound to happen.
     
  4. Klippie

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    Mr_Belowski,

    I spent some considerable time trying to rid my HS10 of this very thing.

    Its probably your DVD player.

    Which make and model do you have?

    The one I settled on is the Philips963SA, it gives wonderful jaggie free pictures in pal progressive scan mode but it has other issues which are a pain.

    Klippie.
     
  5. Bristol Pete

    Bristol Pete
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    What are the other issues Klippie ????

    thanks,

    CB.
     
  6. avanzato

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    Yes I get this on my Z1 with a Pioneer DVD350 via S-video.

    I think it's the de-interlacing if I look closely at the screen it does look like you can see alternate lines, one lagging behind the other.

    I don't know about Prog scan players but I've just knocked up a HTPC and will see how that does (when I get it quiet enough)
     
  7. Bristol Pete

    Bristol Pete
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    Is it safe to assume that a progressive scan enabled DVD player will remove the jaggies then?????.

    Would a non progressive scan component video lead help as well ?????

    mmm, interesting.

    CB.
     
  8. Klippie

    Klippie
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    Captain Benefit,

    The Philips is a bloody pain because there are a few niggles with the operation of the machine, it sometimes starts up with a split screen, it has crap remote directional control and more than a few poeple's machines have bands visible on the left side of the picture....I wonder if this is whats called character!

    Apart from these quirks the machine has outstanding picture quality and the sound is wonerderful.

    I cant bring myself to send it back as I dont know what to replace it with.

    Also I have seen a Primare V10 DVD player which was not pal progressive its picture was as good as the Philips but it had very bad lip-sync problems .

    I tried a Toshiba SD210E through component connections to my HS10 and to me it was almost unwatchable because of the jaggies.

    I dont know how to advise you as nobody has any info on which players show jaggies and which do not but I suspect that not a lot of players can.

    Sorry
    Klippie.
     
  9. Bristol Pete

    Bristol Pete
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    Hi there,

    A quick question regarding the jaggies you mention.

    Is it that bad?

    Does it ruin your overall viewing pleasure?.

    I have to enquire as we discussed this PJ recently,and you were very happy with it, but like everthing you only start to see the faults once you have had it a while.

    I pressume that you have noticed this since you posted your verdict on projectorcentral, assuming that its you, as I suspect it is.

    I really hope that its not that bad for you.

    Get back to me if you can.

    CB.
     
  10. Smurfin

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    in my limited experience, prog scan DOES remove jaggies to a large extent.
     
  11. Mr_Belowski

    Mr_Belowski
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    A bit more info on how bad this problem is for me...


    My Z1 is used for movies (via S-Video) and XBox (also via S-Video). On *some* XBox games I see jaggies. This is only really on racing games, when I'm turning corners and large parts of the image are moving horizontally.

    For example, racing round the virtual Alps in my virtual Merc, in the twisty sections with steep virtual hill-sides next to the track, the hill-sides look a little blurry as I pass them, and the edges of the hillsides are a little jaggy. I don't always see this - the effect is very subtle, but because of the nature of racing games, I'm often fixating on or close to a moving part of the image. For example, as I steer into a corner, I'm looking at the edge of the road at the inside of the turn at the apex. This means that the side of the hill (which is moving horizontally quite quickly) is very close to the bit of the image I'm staring at. So I see the jaggies.

    On other games I don't see the effect at all. I think it depends on the contrast in the image, both at the edges of objects, and the contrast in the textures applied to those objects. So for XBox games it's a minor irritation that makes fast moving stuff look slightly blurry, with slightly jagged edges. It certainly doesn't stop me getting totally engrossed in my games. Also note that when I use the projector for gaming I increase the screen size to about 8 feet across. If I drop it back down to a more reasonable size (say, 6 feet across) the jaggies are still visible, but only just - I've really got to look for them.

    I also dropped the "sharpness" setting on the projector, and it helps a little.

    Now for movies...

    I watched the Matrix last night (for about the 15th time - I love it :)). I started out deliberately looking for the jaggies, and on occasion I could spot them. I'd see them for a second or so every couple of minutes, depending on what was in the scene.

    Then I just started watching the movie, and was totally engrossed. Towards the end it hit me that I'd not noticed the jaggies at all since I stopped looking for them.

    So there you go.


    If you're playing console games on your Z1, you'll notice the jaggies every now and then - especially if you're looking for them. They're probably less pronounced on movies cos DVDs are usually played at 24 frames per second (I think), where as XBox games are usually 60 fps. So the de-interlacer in the Z1 is having to work harder on XBox cos every frame it de-interlaces is different.

    If you're using an interlaced source for DVD movies, again, you'll be able to spot them from time to time if you look for them. I'm going to try the progressive scan option on my DVD player when I get some Component Video cables this weekend - I'll report back.


    Personally, I still think the Z1 is fab. This problem is a minor issue, and I think I can remove it entirely with a progressive scan source. It's an occasional irritation for gaming, and to be honest, a non-issue for movies. I pointed it out to my other half while watching The Matrix, and she couldn't see it at all - she thought I was nuts :)

    For me, because I'm not bothered at all by screen-door, I suppose I'm over-sensitive to any other issues with the image. I guess my brain is saying "woah... you paid £1300 for this... it'd better be perfect... I'm going to make damned sure it is...". It's daft, but I just can't help but look for faults in the image. Maybe if I'd paid £300 for the projector I wouldn't even know there were occasional jagged edges :)
     
  12. ROne

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    I can fix this problem for the z1, have a look at my post on the avsforum.

    It's nothing to with the input of the z1 or source, but my fix applies to VGA so I don't know if it will effect the othe inputs.

    You may have to write down your service menu settings.

    http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=234096

    Give it a go.
     
  13. Bristol Pete

    Bristol Pete
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    Glad to hear that its not that bad.

    One thing I would mention regarding the jaggies being far more pronounced when using the X-box would be its ability to anti-ailise textures and thus remove jaggies.

    I am not an expert on graphics cards but I think that the box uses a n-vidia card which I assume can handle and smooth jaggies to a point, and by far better than the dreaded PS2.

    As you say, the fact that you are playing game son a 6-8 foot screen probably highlights thejaggies more.

    There are component video cables available for the x-box but I am not sure how much they cost.

    Thanks for your post

    CB
     
  14. Mr_Belowski

    Mr_Belowski
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    ROne - I did see that on the AVSForum, but I wasn't keen to go poking around in the service menu.

    If I get a spare couple of hours this weekend I'll have a play and report the results. It looks like a pretty simple procedure. Do you think it'll make a difference to S-Video signals, or is it just proper RGB signals this tweak will affect?
     
  15. ROne

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    Hmm, not sure about S-video, I don't have a service menu yet but there were some references to the service menu on AVSforum.

    If you write down your starting point you will be perfectly okay.
     
  16. Swamp Donkey

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    I am using a Arcam 88Plus hooked up to a Z1 via component. The PAL progressive output features motion adaptive processing, to improve the picture (reduces smearing/artefacts/jaggies and gives a brighter and more stable picture). I have also tried an outboard scaler (Kramer 720DS) which improved the picture further.

    If you don't mind the inconvenience similar improvements can be had going the HT PC route for a lot less money
     
  17. hopdylan

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    Just thought i'd add something on this subject....

    I have just taken delivery of a brand new Z1 (my old one had been used for about 500 hours and had dust on the panels). With the old Z1 I only ever noticed the horizontal lines when it was cold but since setting up the new one last night I can now see this line problem all the time ... I thought it hadn't warmed up so just left it on for a good few hours but still the problem is visible

    So the question is why does the new unit suffer from this artifact even when warm when the old one had it eliminated after a few hours use?
     
  18. -Jay-

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    Hi mate
    Just how bad are these bands? & do you have any pictures of the problem?

    I really have to stop reading these forums it puts me off getting things:rolleyes: :D
     
  19. hopdylan

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    I'm going to try and let it 'wear in' over the weekend - if the problem still exists i will attempt to get some pics

    Dylan
     
  20. Crocodile JD

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    ROne

    If VB and horizontal jaggers seem to be opposite poles related as it were, maybe it could help VB on my PLV30. I don't notice horizontal jaggers. May be mine is set toward other end of the scale.

    What is the description against the parameters 13, 14, 15 (was it) in your Z1 menu that made the difference. Maybe I can find the same in my PLV30 menu and do some tweaking.

    Crocodile JD
     

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