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Z2 positioning

Discussion in 'Projectors, Screens & Video Processors' started by zAndy1, Nov 13, 2003.

  1. zAndy1

    zAndy1
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    Am I right in thinking that if I ceiling mount the Z2 I can in theory mount it as close to the ceiling as possible and use the lens shift to move the image down to match the screen? I'm just not 100% certain it's possible to do that and it will affect which LMP mount length I get (want 150mm if I can get away with it).

    Cheers
    Andy
     
  2. Kramer

    Kramer
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    Exactly what it's designed for ;)

    Link to a video around here somewhere illustrating the feature in action.
     
  3. GrahamC

    GrahamC
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    Can someone shed a little light for me? If the Z2 lens shift is set to 0 horizontally and 0 vertically, i.e. no shift set at what position is the image displayed, is the lens centre at the centre of the image (Z2 will be especially table top mounted). :confused:
     
  4. zAndy1

    zAndy1
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    I would imagine the lens centre will be below the image. Doesn't if fire upwards slightly? Going to go look for some specs I'm sure I've seen this info somewhere...

    Andy
     
  5. buns

    buns
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    for an upright horizontal mount, the lens will be at the bottom centre of the screen

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  6. GrahamC

    GrahamC
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    :hiya: Ta very much.
     
  7. calscot

    calscot
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    At maximum lens shift the middle of the lens will either be at the top of the picture or the bottom depending on which way you shifted.

    Therefore you can't project higher or lower than the center of the lens without tilting and using keystone correction.

    So if projecting from a coffee table without tilt, the highest the bottom of the picture will be is at the height of the lens, just above the coffee table height.

    If projecting from the ceiling the lowest the top of the picture will be is the the height of the lens.

    Therefore it is inadvisable to mount your pj as high as possible as this gives no leeway to adjust. Best to mount a couple inches below where it needs to be, giving you room to move the picture down a tad to fit it to the screen.

    The lens shift is fantastic as it allows you to be more relaxed about measurements when putting up the mount and the screen, meaning you'll be ok as long as you're accurate within a couple of inches...

    Also my electric screen doesn't always seem to come down in the exact same place all the time, it varies by about 5mm. A quick tweak on the lens shift and it fits perfectly.

    I couldn't cope without lens shift now.
     
  8. jGrahamD

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    The lens shift on the Z2 is greater than on the Z1. Vertically, it will shift the image by one full screen height up or down, so the top of the image could be half a screen below the lens. The manual does say that image quality is best when it is near the central position. I don't have one yet so I can't comment from experience, but the diagrams in the manual are pretty clear about what is possible.
     
  9. buns

    buns
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    well it is common that using extremes of anything is more likely going to result in problems, thats fairly much true in everything

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  10. renardi

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    Hello,

    Can The Z2 be mounted on the ceiling without being upside down?

    The top of the screen would be positioned on the ceiling.

    Thanks,

    Christophe.
    Belgium.
     
  11. MattB

    MattB
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    I wondered this too - if the projector offsets up when the lens shift is centred, ceiling mounting upside-down should allow you to work closer to the sweet spot and minimise distortions at the bottom edge. Correct?

    I will use an HTPC so flipping the image would not be a problem, or can the projector do it?
     
  12. nunew33

    nunew33
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    There'll be at least 35 people who can tell you as of monday.

    My lmp mount is 10cm, ive banked on the shift lens sorting this out. The video of the lens shift in acton clearly shows that in the centre the image is above the lens and when shifted the bottom of the shifted image is where the top was in centre. So in theory when upside down. if 10cm from ceiling I wont use that much lens shift to get the image say 20cm from the ceiling.

    Like i said as of monday;) therell be alot of poeple who can answer this for you.
     
  13. Quatermass

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    I thought the bit from the ProjectorCentral review which talked about lens shift was quite informative:

    “anywhere within the first half to maybe two-thirds of the allowable lens shift range will have no consequential impact on the image”

    That seems to give quite a bit of scope for shifting without ruining pq. :)
     

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