Digital Projection TITAN sx+-500, User Manual

Page: 26 / 120

Rev C March 2008 page 2.6
2. Installation Digital Projection
TITAN sx+-500
User Manual
Notes
For more information about
Throw ratio factor (TRF), see
Useful lens calculations, later
in this section.
Choosing a lens
A number of lenses are available for use with the projector. Which lens you choose
will depend on the screen size, image aspect ratio and projection distance.
If you are simply connecting the output of a camera or computer directly to the
projector, then the image size (in pixels) may well be fixed. If, however, you are
using commercially available image processing equipment, such as the Digital
Projection MMS 1000 or VIP1000, you may be able to resize the image to fit the
DMD.
If the image does not fill the full width of the DMD, this effectively increases the
throw ratio of the lens. This can be corrected for by applying a Throw ratio factor.
Method one: using the lens chart
For the screen sizes listed below, use the charts on the following page, to choose
the most suitable lens.
any full width image, including:
4:3 = 1.33:1 1400 x 1050 pixels (native resolution)
1.66:1 (Vista) 1400 x 843 pixels
16:9 = 1.78:1 1400 x 788 pixels
1.85:1 1400 x 757 pixels
2.35:1 (Scope) 1400 x 596 pixels
full height image
A Throw ratio factor (TRF) of 1.07 would need to be applied, for the charts to be
correct for the following image (multipy the required screen width by 1.07 before
consulting the charts):
5:4 = 1.25:1 1313 x 1050 pixels
Method two: by calculation
See the calculations, on the page immediately following the lens chart.