Digital Projection TITAN sx+-500, User Manual

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Rev C March 2008 page 2.9
Digital Projection
TITAN sx+-500
User Manual 2. Installation
Notes
The Throw ratio for a particular
lens is fixed, but assumes that
the image fills the width of the
DMD.
For images that do not fill the
width of the DMD, the Throw
ratio is effectively increased. To
correct for this in these
calculations, a Throw Ratio
Factor (TRF) is used.
Lens extension is measured
when the lens is focussed at
infinity, and fully extended. At
other focus settings, the
extension could be up to 10mm
less
Useful lens calculations
The following lens calculations may be useful:
Throw ratio = Throw distance
Screen width
Throw ratio factor (TRF) = DMD width in pixels = 1400
image width in pixels image width in pixels
Therefore:
Screen width = Throw distance (from outer end of lens)
Throw ratio x TRF
Throw distance = Screen width x Throw ratio x TRF
The throw distance calculated above is to the outer end of the lens. For each lens,
the nominal distance between the front of the projector and the outer end of the lens
(lens extension) will be as listed below:
lens extension
0.73 : 1 fixed lens 105-607 204mm (8.0in)
1.2 : 1 (3 - 15m) fixed lens 105-608 268mm (10.6in)
1.2 : 1 (1.2 - 2.0m) fixed lens 105-609 268mm (10.6in)
1.5 - 2.02 : 1 zoom lens 105-610 194mm (7.6in)
2.02 - 2.77 : 1 zoom lens 105-611 159mm (6.2in)
2.77 - 4.51 : 1 zoom lens 105-612 152mm (6.0in)
4.51 - 7.53 : 1 zoom lens 105-613 118mm (4.7in)
lens extension,
measured from front
of corner post