convergence & DLP

Discussion in 'Archived Threads 2001-2004' started by Carl Mulder, Nov 27, 2002.

  1. Carl Mulder

    Carl Mulder Stunt Coordinator

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    Now having owned a toshiba widescreen 42' rear projection tv for a year now feel that I am now the convegence master.
    The convergence is centered, every square is the same size.
    I have literally restructured my entire grid and you have to see it, it looks simply amazing now, perfect.

    Now i'd like to know if the same covergence exists in DLP tv's because I have struggled with the Toshiba set to get it looking at it's best. Admittedly it looks great now but is DLP as much hassle?
    Does a convergence exist on DLP?
    Any thoughts?
     
  2. Jack Briggs

    Jack Briggs Executive Producer

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    Carl, this is a Display Devices question and not a Widescreen Review-specific question.
     
  3. RANDY FISHER

    RANDY FISHER Second Unit

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    "Does a convergence exist on DLP?"

    Carl no. A DLP device is a fixed resolution display device. It has a single gun/lamp configuration. It would not have (3) separate guns to converge. The 3 colors are formed by shining light thru a spinning "color wheel" and off the reflective surface of the DMD (micro mirror device) chip. When setting up front projection DLP or LCD you size the image to the screen and focus it. Done. I assume there could still be some geometry issues that may need adjustment on DLP rear projection but that could happen with any display technology.

    Randy
     
  4. Allan Jayne

    Allan Jayne Cinematographer

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    Note that most LCD projectors do have a convergence issue, they have three tiny LCD panels and the light from the projection lamp is split three ways using prisms and mirrors. In almost all cases the LCD panels are converged at the factory and glued in place, and if there is a convergence error, it generally cannot be fixed without replacing all three panels and perhaps some related components such as the prism. Even if you could converge it at home, we are dealing with precision to a thousandth of an inch.
    The current consumer DLP offerings, both front and rear projection, use just one light path, one DMD panel, or chip, (and a color wheel) because the panels are so expensive.
    Any projector (front or rear) may or may not have chromatic aberration in its lenses, which results in rainbow fringes that can be confused with misconvertence. Lenses may also have pincushion distortion, etc.
    Video hints:
    http://members.aol.com/ajaynejr/video.htm
     
  5. Carl Mulder

    Carl Mulder Stunt Coordinator

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    thanks alot .much appreiciated.
     

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