Christie RPMX-D120U Setup Manual page 10

Section 2: Installation & Setup
Screen Size and Type
Ambient Lighting
Other Considerations
2-2
Choose a screen size most appropriate for your lens and application. Keep in
mind if the intended use of the projector is to display text information, the image
size must be large enough to allow the audience to view all text clearly. The eye
usually sees a letter clearly if eye-to-text distance is less than 150 times the
height of the letter. Small text located too far from the eye may be illegible at a
distance no matter how sharply and clearly it is displayed.
To fill a screen with an image, the aspect ratio of the screen should be equal to
the aspect ratio of the image. The aspect ratio of an image is expressed as the
ratio of its width to its height. It is best to choose a screen with a screen aspect
ratio most appropriate for your intended application. Screens with an aspect ratio
of 5:4 are recommended for use with these projectors.
There are two types of screens that are best suited for rear screen installations:
diffused and optical. A diffused screen has a surface, which spreads the light
striking it. Purely diffused screens have a gain of less than 1. Optical screens take
light from the projector and redirect it to increase the light intensity at the front of
the screen.
The high brightness of this projector is well suited for locations where ambient
lighting might be considered less than ideal for projection. A typical room with
ceiling lights and windows rarely requires special attention. Contrast ratio in your
images will be noticeably reduced only if light directly strikes the screen, such as
when a shaft of light from a window or floodlight falls on the image. Images may
then appear washed out and less vibrant.
In general, avoid or eliminate light sources directed at the screen.
Other considerations and tips that can help improve your installation:
•
Ventilation is an important factor when preparing a projection room. The
ambient temperature should be kept constant and below 35°C (95°F).
Keep the projector away from heating and/or air conditioning vents.
Changes in temperature can cause drifts in the projector circuitry, which
may affect performance.
•
Keep the projector away from devices, which radiate electromagnetic
energy such as motors and transformers. Common sources of these are
slide projectors, speakers, power amplifiers, elevators, etc.
•
Use an optical mirror for rear screen installations to shorten the optical
light path and use less space in the projection room.
•
When designing a projection room, consider positioning the projector
and screen where maximum audience coverage and space efficiency is
achieved. For example, placing the screen along the larger wall in a
rectangular room reduces audience coverage.
RPMX-RPMSP-D120U & RPMSP-D275U Setup Guide
020-100038-02 Rev. 1 (09/08)