Projector's with manual zoom and watching different aspect ratio's!

Discussion in 'Displays' started by Dan Mercier, Feb 18, 2004.

  1. Dan Mercier

    Dan Mercier Stunt Coordinator

    Aug 24, 1999
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    Well it's a long subject line but here's my current concern.
    I have an Infocus LP350 which has a manual zoom and is a 4:3 projector.
    I have a 16x9 screen which currently has no matting for different ratios.

    I find that if I watch a DVD (dvd player is in widescreen mode)
    and set the project to enhanced widescreen, I end up having to tilt the projector to get it to line up with the screen.
    That is if I have previously watched or played games in 4:3 aspect ratio.
    Not sure if I'm being clear here but the problem is basically
    that with my screen (16x9) and using manual zoom I also have
    to tilt the pj up or down to get it to line up so I have max
    size 4:3 (fills height of screen) vs. a 16x9 movie which fills height and width?

    Can anyone else explain to me how they do this or if
    their PJ just keeps picture in the right spot?

    Another way to explain this is in 16x9 mode the pj would actually project the image
    roughly center vertically of my screen. But if I zoomed this 16x9 image down so it fits vertically in the screen it is no longer center...

    Hope someone can understand my problem if not I'll have to draw a picture in MS paint or something.

  2. Burke Strickland

    Burke Strickland Second Unit

    Jul 31, 1997
    Likes Received:
    I understand what you are saying. My Sony VPL-W400Q does that too. If the aspect ratio changes, the image lands on a different area of the screen (or even part way off the screen), so I have to either fiddle with my moveable blackout mattes or shift the position of the projector to get it back to a centered position. Since I like to keep the vertical height constant for all aspect ratios and just vary the image width, it requires some juggling each time the aspect ratio switches to another format.

    Unfortunately some projectors just do that (shift the image as aspect ratio changes), while others seem to be a bit more consistent on the placement/positioning of the image on the screen regardless of zoom level or aspect ratio.

    Sorry I don't have an easy "fix" for the situation you've described, but at least you didn't have to draw me a picture. :>)

  3. Harry Lincoln

    Harry Lincoln Stunt Coordinator

    Sep 29, 2000
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    I have an Infocus X1, it does the same thing when the zoom is adjusted - the bigger the image size the higher up the bottom of the image is. I have my DVD player connected via the VESA input (progressive component signal), in the menu under picture>advanced there is an adjustment for the vertical position, I use this to move the image back to the correct spot. This adjustment is only available on the VESA input, I'm not farmiliar with the LP350 but it might be worth looking into.
  4. DavidLW

    DavidLW Stunt Coordinator

    Nov 21, 2003
    Likes Received:
    I have an X1 and I never have to re-center an image while viewing ( no matter what format it is). But the zoom function will cause the image to go off center vertically. I never use the zoom so it doesn't matter to me.

    All projectors, except maybe a few CRT's, will do this. It's because a projector is designed to project an image above the lens (when on a table). If you notice the video image coming out of your projector, it's only coming through half of the lens. The top half if the projector is on the table or the bottom half if it's mounted upside down on the ceiling. The center of the whole image the lens sees is actually more than a foot below the video image on the screen (when the projector is on a table). The top half has the video portion and the bottom half is blank. Put your finger right in front of the lens near the bottom and you will see that it will not block any of the video image until you approach the middle of the lens. So when you zoom in and out the video image get disportionly larger or smaller from the top because it's further from the center than the bottom (again when the projector is on a table). This is probablly more information than you need (or want) to know but at least you know this "problem" is normal for the projector.

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