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Screen Door Effect in 4805

Discussion in 'Projectors, Screens & Video Processors' started by nanumalla, Jul 30, 2004.

  1. nanumalla

    nanumalla
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    Hi,

    I finally got my Infocus 4805 yesterday, tried it out on my wall, I did not find it that impressive. I can see the Screen Door Effect(SDE). I have tried Infocus X1 before and 4805 is no better than X1, except that 4805 is native 16:9 projector. I thinking(or atleast hoping) that the SDE can be avoided with a screen.

    My wall is kind of cream-ish color, I am going to try using a white screen.

    Did anybody on this forum have had this kind of an issue?

    Any input would help me and truly appreciated.

    Thanks,
    Naveen
     
  2. Messiah

    Messiah
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    It might be 16:9 but it only has a resolution of 854x480 so you will need to sit further away from the screen than with a 1280x720 pj to minimise or eliminate the SDE.

    IIRC the X1 was an 800x600 pj so in 16:9 mode it too had a horizointal resolution of 480 lines so I do not see why the SDE should be any different on one than the other.
     
  3. inzaman

    inzaman
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    How far away are you from the screen, also what was being projected at the time i.e light grey colours etc.

    I saw one last saturday and was about 1.5 width away and couldnt see any sd, i was very impressed with the unit but bearing in mind my current pj is lcd.
    This was the first dlp that i didnt get any rainboe effect from or eye strain etc.
     
  4. nanumalla

    nanumalla
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    Hi Messiah,

    there is no difference in SDE between X1 and 4805. do you think adding a screen(as of now, I am using a wall)would make a difference?

    Thanks,
     
  5. nanumalla

    nanumalla
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    Hi Inzaman,

    I was sitting at 13ft(156 in.) away from the wall and the width of the picture was 77in., so that is 2x. The tried these movies: MI(first one), Monsters, Harry Potter(first one), U-571. I must say when there are bright colors(red, blue or even human skin color) it is clear and perfect, even face closeups were really good, but during light colors or even text, I can see SDE, for example first scene in Harry portter(if you have seen it), when dumbledoor is collecting the light from street lights, I could clearly see pixels for the street lights and also the grey parts of the scene.

    thanks,
     
  6. Gary Lightfoot

    Gary Lightfoot
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    Generaly, sitting 2x away from a DLP svga res pj should be enough for SDE to not be a factor, but it looks like you have good eyes for it..

    Try a slight defocussing of the lens - this can be done without noticably effecting the image, so have a go at doing that and see what results you get.

    I have heard people mention that changing from a white screen to a grey screen, and in some cases, a lower gain screen reduced the apparent screendoor, but that's a subjective evaluation based on already having a white screen. Higher gain screens can make it worse apparently.

    Some people have had similar results using a lens filter (FL-Day for instance), and that's cheaper than buying a screen. The only other way is to make the image smaller or sit further back.

    Gary.
     
  7. Messiah

    Messiah
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    Many people see SDE with 1280x720 pjs so it does not surprise me that you may see it with a pj with only 480 horiz resolution.

    "there is no difference in SDE between X1 and 4805" That's what I'm saying. Why should there be? They are the same resolution when watching 16:9 material. If you saw SDE on the X1 then I would be surprised if you did not see it on the 4805. The only other way, AFAIK, is to slightly defocus like many with LCD pjs do. I don't think different screen material will make any difference other than maybe a grey screen as this may mask the darker pixel (mirror) structure (the grid spacing between the mirrors) slightly.
     
  8. Messiah

    Messiah
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    :D At least we're on the same wavelength Gary. How you keeping?
     
  9. Gary Lightfoot

    Gary Lightfoot
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    I'm fine thanks!

    Looks like we posted at the same time more or less... Glad we didn't contradict each other! :D

    How's things with you?

    Gary.
     
  10. monopole

    monopole
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    Not entirely true if the 1280x720 pj is an LCD like the Sanyo PLV-Z2. Over on avsforum.com someone compared the Z2 to the InFocus 4805 (858x480 resolution) and the SDE (screen door effect) was actually less noticeable on the 4805 than on the Z2. This is because the spacing between the pixels on an LCD panel is generally much greater than the spacing between the micromirrors on a DLP chip.

    from: http://www.avsforum.com/avs-vb/showthread.php?postid=3936437#post3936437

     
  11. Messiah

    Messiah
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    :confused: But no one's comparing the 4805 with an LCD here and I never mentioned an LCD. The original query made comparison of the 4805 against the X1 and that is what I based my response/s on. DLP all the way :D
     

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