2. General
Positioning the projector
FLOOR
SCREENSCREEN
PD
ACD
SCREEN
SW
SW
SHB
SHB
CD
Image 2-5
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 coincidi
ng 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 respectto the DMD (P) which result in a shifted image on the screen (Off-Axis). A 100% shift means that
the centre point of the projected image is shifted by half the screen size. In other words, the centre 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.
R59770057 CLM HD8 15/03/2010
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