4805 position question

Discussion in 'Displays' started by John*DB, Sep 15, 2004.

  1. John*DB

    John*DB Stunt Coordinator

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    Math questions for ya. I don't mind doing the math myself if someone wants to tell me how.

    How high can my 4805 sit (on a stand...not ceiling mounted with inverted view) with a ceiling that is 7'10"?

    I cannot ceiling mount this so I have to figure out how high I sit the proj behind the couch so the couch back and viewers heads are not in the way of the image...no shadow puppets or MST3000 impersonations in my house!!

    Oh yeah...projector will be 14 ft from screen
     
  2. John*DB

    John*DB Stunt Coordinator

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    I have a reeeeal good feeling I am going to have to put this projector upside down (but not mounted) and invert the image. I think the image will throw too high at 13-14 feet back at 4-4.5 feet high with an 8 foot high ceiling.

    Soooooooo.... NOW my question is, if I SIT the PJ on its TOP and switch to ceiling mount view...

    Will that affect ventilation or any thing else since "it is not designed to do that"

    The image is what I will almost definitely use.


    [​IMG]
     
  3. Jack Gilvey

    Jack Gilvey Producer

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    What size image? The lens will need to be either approximately 1 foot above the top or 1 foot below the bottom of the image.

    Try the projection calculator on this page .
     
  4. John*DB

    John*DB Stunt Coordinator

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    I have used thc calculator many times. It does nothing to explain the offset or help you configure the height of the 4805 with an offset (of what I have gathered) to be 127%.

    The height of my image will be between 3.4 and 4 feet. But I need to calculations of how to figure out pj height. Where does the "1 foot" come from?
     
  5. Jack Gilvey

    Jack Gilvey Producer

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    Your "calculation" would be to add 11" to the desired top of the image to get the height of the lens.
     
  6. John*DB

    John*DB Stunt Coordinator

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    Edit!! I just realized the link you have me was not the regular calculator...its an excel program.

    Might have questions about this one too though.

    Thanks you for the link!!
     
  7. John*DB

    John*DB Stunt Coordinator

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    The problem is I can only change the yellow box. I want to change the projector height!

    I want to know where my screen would need to go if I had my pj at 6 or 6.5 feet w/ a 16:9 screen w/ 92" diagnol.
     
  8. Jack Gilvey

    Jack Gilvey Producer

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    For a 92' diagonal image, it shows the offset to be 1.04'. So, the difference in height, the drop, from the center of the lens to the top of the image is 1.04'. Subtract 1.04' from the height the pj lens to find where the top of the image will be. The diagram is useful.
     
  9. John*DB

    John*DB Stunt Coordinator

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    gotcha[​IMG]
     

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