2. Configurations, requirements and restrictions
AUDIENCE BACKSTAGE
R/C
R/T
FLOOR
S
C
R
E
E
N
Image 2-7
Rear projection
Positioning the projector
FLOOR
SCREENSCREEN
PD
A
CD
SCREEN
SW
SW
SHB
SHB
CD
Image 2-8
Projector positioning
The projector should be installed at right angles (horizontally and vertically) to the screen at a distance PD. Note the distance (A)
between lens centre and table surface is slightly variable. This distance (A) is nominal 35 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 calcul
ate the distance CD for On-Axis projection: CD=SH/2+B-A
R5905158 HDF W SERIES 10/07/2012
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