Christie CP2000-XB, Setup Manual

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2-8 CP2000-XB Setup Guide
020-100250-02 Rev. 1 (06-2009)
Section 2: Installation & Setup
2.3.2 Throw Distance
Throw distance is the distance between the projector and the screen ( Figure 2-12 ). For any installation,
placing the projector at an accurate throw distance is necessary in order for the image size to closely match
your screen – the farther the projector is from the screen, the larger the image. With zoom lenses, you’ll want to
know the approximate minimum and maximum image sizes possible from a given throw distance so that the
most appropriate lens is installed at the site (throw distance / screen width = throw ratio of lens).
Calculating Throw Distance
Once you know the screen size and lens type present, calculate the required throw distance.
NOTES: 1)
If your projector is tilted up or down in relation to the screen, typical in large venues and/or
elevated installation, throw distance still represents the smallest measurement between the screen and front
bezel.
2)
Remember that throw distances are calculated from the screen to the front bezel of the projector
rather than its foot centers. To figure throw distance from foot centers, add 8.74” (22.2 cm).
As shown in Figure 2-12 , throw distance is approximately equal to the full horizontal width of the screen
multiplied by the type of lens you are using. For example, if you are using a 1.25:1 lens, the proper throw
distance value will be approximately 25% more than that of the full screen width. Once you know your screen
width and lens, you can estimate throw distance needed. Or, if you know the available throw distance
beforehand, you can determine what images sizes are possible with a given zoom lens.
Important!
For
proper placement in any installation, use the throw distance formula provided for your lens. In addition, please
keep in mind that due to lens manufacturing tolerances for lens focal length, actual throw distance can vary
±5% or more between lenses described as having the same throw ratio.
Figure 2-12 Estimating Throw Distance: Example
45 f
t.
Throw
Distanc
e
Screen x Throw Ratio = Approx. Throw Distance