Christie DS+60 User Manual page 12

Section 2: Installation and Setup
2-6 Christie DS+60 User's Manual
Vertical and horizontal position
The correct vertical and horizontal position of the projector in relation to the screen
depends on the lens type and the screen size. Ideally, the projector should be
positioned perpendicular to the screen. This way, the image will appear rectangular
instead of keystoned (trapezoidal).
The vertical position of the image can be offset – that is moved above or below the
optical axis (lens center) by adjusting the fully motorized lens mount using the
keypad. The amount of vertical offset available depends directly on the lens installed
in the projector and can be slightly limited if horizontal offset has been applied.
Vertical offset can also be expressed as the percent of half the image height OR the
number of pixels of shift from lens center. Refer to Figure 2.2 for some illustrated
examples of vertical offset.
Table 2.1 along with Figure 2.3 show the maximum vertical offset of a lens or
alternatively, how much of your projected image will appear above or below lens
center if the maximum vertical offset is applied using that lens.
Table 2.1. Lens Offsets
Lens Type Vertical Offset
(% of half height)
% Pixels
0.8:1 fixed 12%
1.2:1 fixed 120% +/-630
1.3-1.7:1 120% +/-630
1.7-2.5:1 120% +/-630
2.5-4.0:1 120% +/-630
4.0-7.0:1 120% +/-630
% Offset = # pixels of offset / half panel resolution x 100.
Figure 2.1. Estimating Throw Distance
Maximum amount of
projected image above or
below lens center
% Pixels
+/-63 56% +/-588
110% +/-1155
110% +/-1155
110% +/-1155
110% +/-1155
110% +/-1155
Horizontal Offset Maximum amount of
(% of half width) projected image to one
side of lens center
% Pixels %
7% +/-48 53%
78% +/-546 89%
78% +/-546 89%
78% +/-546 89%
78% +/-546 89%
78% +/-546 89%
Pixels
+/-748
+/-1246
+/-1246
+/-1246
+/-1246
+/-1246