Benq Projector MP780 ST+ Manuel D’Utilisation

Positioning your projector

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The distance from the projector lens to the screen, the zoom setting (if available), and the 

video format each factors in the projected image size.

The projector should always be placed horizontally level (like flat on a table), and 

positioned directly perpendicular (90° right-angle square) to the horizontal center of the 

screen. This prevents image distortion caused by angled projections (or projecting onto 

angled surfaces). 

If the projector is mounted on a ceiling, it must be mounted upside-down so that it 

projects at a slightly downward angle.

You can see from the diagram on page 

, that this type of projection causes the bottom 

edge of the projected image to be vertically offset from the horizontal plane of the 

projector. When ceiling mounted, this refers to the top edge of the projected image.

If the projector is positioned further away from the screen, the projected image size 

increases, and the vertical offset also increases proportionately.

When determining the position of the screen and projector, you will need to account for 

both the projected image size and the vertical offset dimension, which are proportional to 

the projection distance.

BenQ has provided a table of screen sizes to assist you in determining the ideal location for 

your projector. There are two dimensions to consider, the perpendicular horizontal 

distance from the center of the screen (projection distance), and the vertical offset height 

of the projector from the horizontal edge of the screen (offset).