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Focal position for fixed panel projectors.

Discussion in 'Projectors, Screens & Video Processors' started by Ken, Jan 15, 2002.

  1. Ken

    Ken
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    In the pursuit of perfection (within one’s means), where in the zoom range, would you say was the best position for a fixed panel projector?
    Max zoom - furthest from the screen, min zoom - closest to the screen, or in the middle.
    Though I have mine near to max zoom, I have been wondering if the min zoom would have less optical interference and possibly better image clarity, though I suppose it would depend to some extent on the zoom in use. What are your thoughts on this?
    Ken
     
  2. Chris Frost

    Chris Frost
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    Ken,
    This all depends on the optical accuracy of the lens. The centre portion of the lens is usually the most accurate, so I would suggest maximum zoom (projector furthest from screen) would give the best results.

    Regards
     
  3. Ken

    Ken
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    Thanks for the reply Chris,
    This was my thinking when I did my set up, it is always nice to have confirmation though.
    Ken
     
  4. Roland @ B4

    Roland @ B4
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    Most zoom lenses are at theire least efficient at the longest throw. Some by as much as 50% light drop off.
     
  5. Chris Frost

    Chris Frost
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    Well, you learn something new every day!
     
  6. jrwood

    jrwood
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    So would it be better to have a projector say

    1) 20 foot back with the zoom turned right down (decent sized picture)

    2) 10 foot back with the zoom mid way (decent sized picture)

    3) 10 foot back with the zoom turned right up (for even larger picture!)

    Interesting topic :)

    James
     

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