Installation
Runco VX-44d/-55d Owner’s Operating Manual 21
PRE
L
IMINAR
Y
Vertical and Horizontal
Position
Proper placement of the projector relative to the screen will yield a rectangular,
perfectly-centered image that completely fills the screen.
Ideally, the projector should be positioned perpendicular to the screen and in such a way
that the lens center and screen center are aligned with each other, as shown in
Figure 3-2.
Figure 3-2. Projector Placement
Vertical and Horizontal
Lens Shift
If it is not possible to align the projector and screen as shown in Figure 3-2, you can use
the lens shift controls to center the image on the screen. Lens shift is generally expressed
as a percentage of the screen height or width, as shown in
Figure 3-3 and Figure 3-4.
Figure 3-3. Vertical Lens Shift
Height
Projection Distance
Ceiling
Ceiling Installation
Screen
Height
Floor
Lens Center
Projection Distance
Floor Installation
Lens Center
x
Lens Center
x
Screen Lens Center
Base plate
to lens center =
approx. 6-7" (depending
on the amount of lens shift)
50% Height
Lens Shift
(0.5 x H)
100% Height
Lens Shift
(1.0 x H)
150% Height
Lens Shift
(1.5 x H)
Screen Center
0%
Note: This is a general example of lens shift. Lenses vary in their shift capabilities. No
particular lens or projector is used in this example.