Projector Position And Mounting - Christie Roadster S+12K User Manual

2.3 Projector
Position and
Mounting
Throw Distance 
Vertical & Horizontal 
Position
Roadster & Mirage S+/HD User Manual
020-100002-04 Rev. 1 (12-2008)
Installation type, screen type, and lighting all affect where the projector is positioned.
In addition, both throw distance (the distance between the projector and screen) and
vertical position (the height of the projector in relation to the screen) must be
determined for every new installation. Both depend on the screen size and lens type
you are using. Ensure the room can accommodate the required position of the
projector for the chosen screen size.
Figure 2.19. Estimating Throw Distance
For any installation, an accurate throw distance (TD) must be determined in order for
the image to be of the right size for your screen–the farther the projector is from the
screen, the larger the image. Throw distance is the distance between the projector's
front feet axes and the screen (Figure 2.19), and is roughly equal to the horizontal
width of the screen multiplied by the throw ratio of the installed lens. Once you know
your screen size and lens, you can estimate throw distance needed. For example:
•
Screen Width = 10 feet
•
Lens Type is 0.7:1
•
Throw Distance (TD) = 10 feet x 0.7 = 7 feet
NOTES: 1) If your projector is slightly tilted in relation to the screen, typical for
large venues or flown installations, throw distance still represents the smallest
measurement between the screen and front feet. 2) For proper placement in an
installation, always refer to the throw distance formula and/or chart for your lens as
listed in Appendix D. Keep in mind that due to lens manufacturing tolerances for
lens focal length, actual throw distance can vary ±5% between lenses described as
having the same throw ratio
THE VERTICAL POSITION
size of the screen and the lens type. Correct vertical position helps ensure that the
image will be rectangular in shape rather than keystoned (having non-parallel sides)
and that image focus and brightness both remain optimized.
(SEE APPENDIX D)
of the projector in relation to the screen also depends on the
Installation & Setup
2-15