DLP Artifacting

Discussion in 'Archived Threads 2001-2004' started by Remy, Feb 17, 2003.

  1. Remy

    Remy Auditioning

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    Gents,

    Has anyone heard of such a thing called DLP Artifacting?

    Remy
     
  2. Jonathan Smith

    Jonathan Smith Stunt Coordinator

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    I have seen that term used as another name for the rainbow effect. Check out the article on projectorcentral.com about DLP vs LCD if you haven't heard of that, it gives a pretty good and simplistic explanation.
     
  3. Allan Jayne

    Allan Jayne Cinematographer

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    Due to the expense of DLP picture generating elemtns (panels) only one is used in a consumer grade TV, as opposed to three LCD panels or three CRT's in projection TV's with those technologies.

    With only one panel, it is necessary to "time share" it to produce red, green, and blue sub-images in quick succession with a color wheel. There will alwasy be red, green, and blue fringes seen around object in the picture evey now and then -- rainbow artifacting -- different people will find it more or less obtrusive. It has to do with your eye movement following the action in the movie, in which case the successive red, green,a nd blue sub-images for a given video frame don't all land in the same place on the retina of your eye. The faster the rotation of the color wheel (more specifically the more red/green/blue alternations per second), the less obtrusive the rainbowing will be.

    Video hints:
    http://members.aol.com/ajaynejr/video.htm

    Slightly before NTSC composite video was invented, a color wheel system using a single direct view CRT was conceived, but never caught on. I was told it was to have 72 interlaced fields per second (24 of each color) whereas today's DLP TV's typically have at least 180 frames per second using each incoming or constructed 480p video frame 3 times (red, green, blue sub-images).
     

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