Image offset

Discussion in 'Displays' started by corona13, Aug 13, 2006.

  1. corona13

    corona13 Stunt Coordinator

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    trying to figure out my projector issues. Am I doing this correct?

    I am looking at two projectors, inFocus IN76 and Optoma HD72 and will be doing a ceiling mount.

    InFoucs has a 125% image offset. Basically, from what I understand, the center of the projectors lens will have be 25% above the top of the image.

    Optoma HD72 has a 154% image offset, so the center of the lens will be 54% above the top of the image....correct?

    Thank you for the help!
     
  2. Jim Mcc

    Jim Mcc Producer

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    I don't know the offset of the Optoma, but you're wrong about the IN76's offset. The IN76's offset is 116%, which is pretty small, and one reason why I'm interested in it for my low ceiling. So yes, the center of lens would need to be mounted 16% of the image height above the top of screen. If price is no concern, the IN76 has gotten better reviews than the Optoma.
     
  3. corona13

    corona13 Stunt Coordinator

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    you are right. I got the 125% from a offset calculation example on the infocus website. the 125 was obviously hypothetical

    thank you for the feedback
     
  4. Ryan_Papineau

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    Could you perhaps post some review links? I looked at some of the reviews on ProjectorCentral and it seemed to be somewhat of a tossup between the two with the advantage in my head going to the HD72 as it seems easier to find deals on it.
     
  5. Jim Mcc

    Jim Mcc Producer

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    Projectorreviews.com
     
  6. Neil Joseph

    Neil Joseph Lead Actor

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    Moving this to displays.
     
  7. Allan Jayne

    Allan Jayne Cinematographer

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    Many projectors have adjustable image offset so you are not constrained to exactly 16% of the screen height above the screen top edge or whatever.


    When there is both an adjustable horizontal offset and vertical offset, usually you cannot have the maximum offset for both horizontal and vertical at the same time, and the exact formula is hard to predict.
     
  8. corona13

    corona13 Stunt Coordinator

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    Thanks Allen. I think I need to go with the Panny 900 or Sanyo Z4. They both seem like good 720p projectors. THey are both LCD, where as I was looking at DLP. Is there a big difference between LCD and DLP?
     
  9. Allan Jayne

    Allan Jayne Cinematographer

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    LCD's have less deep blacks but no rainbow effects. Also on average LCD's have wider inter-pixel gaps leading to a more pronounced "screen door effect". DLP's on average have more "crawl effects" (dithering) more noticeable on saolid color patches and when you are up close.

    Unfortunattely it is not always easy to audition projectors but if you can, watch it for at least an hour. A few people get headaches from the way (color wheel and single image forming panel) most of the current DLP's operate.
     

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