Barco RLS W12 User Manual - page 17
RLS W12 02/12/2014
9
2.General
Positioning the projector
FLOOR
SCREEN
SCREEN
PD
A
CD
SCREEN
SW
SW
SH
B
SH
B
CD
Positioning projector
The projector should be installed at right angles (horizontally and vertically) to the screen at a distance PD. Note the distance
(A) between lens center and table surface is slightly variable. This distance (A) is nominal 14 cm in case all feet are turned in
completely and the vertical lens shift is set to zero (0).
On axis / off axis projection
The position of the projector with reference to the screen may also be different depending on the installation. Basically the
projector can be positioned in On-Axis or Off-Axis configuration. On-Axis configuration means that the projector is positioned
so as to have the centre of the lens coinciding with the centre of the screen. Off-Axis projection is obtained by shifting the
lens up, down, left or right. Several parameters can be calculated determining the position in any installation.
Formula to calculate the distance CD for On-Axis projection: CD = SH/2 + B - A
Shift range
The lens can be shifted with respect to the DMD (P) which result in a shifted image on the screen (Off-Axis). A 100% shift
means that the center point of the projected image is shifted by half the screen size. In other words, the center point of
the projected image falls together with the outline of the image in an On-Axis projection. Due to mechanical and optical
limitations it’s recommended to keep the shift values within the field of view (F) as illustrated below. Within these shift
ranges the projector and lens perform excellently. Configuring the projector outside these shift ranges will result in a slight
decline of image quality.