Obtaining A Preferred Projected Image Size - InFocus IN102 Reference Manual

Obtaining a preferred projected image size

The distance from the projector lens to the screen, the zoom setting, and the video
format all factor into the resulting projected image size.
4:3 is the native aspect ratio of this projector. To be able to project a complete 16:9
(widescreen) aspect ratio image, the projector can resize and scale a widescreen
image to the projector's native aspect width. This will result in a proportionally
smaller height equivalent to 75% of the projector's native aspect height.
4:3 aspect image in a 4:3 16:9 aspect image scaled to a 4:3
aspect display area aspect display area
Thus, a 16:9 aspect image will not utilize 25% of the height of a 4:3 aspect image
displayed by this projector. This will be seen as darkened (unlit) bars along the top
and bottom (vertical 12.5% height respectively) of the 4:3 projection display area
whenever displaying a scaled 16:9 aspect image in the vertical center of the 4:3
projection display area.
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).
The modern digital projector does not project directly forward (like older style reel-
to-reel film projectors did). Instead, digital projectors are designed to project at a
slightly upward angle above the horizontal plane of the projector. This is so that
they can be readily placed on a table and will project forward and upwards onto a
screen positioned so that the bottom edge of the screen is above the level of the
table (and everyone in the room can see the screen).
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 12, 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
directly proportional to the projection distance.
InFocus has provided a table of 4:3-aspect-ratio 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).
10 Positioning your projector