Digital Projection E-Vision Laser 15000 Series
Appendix B: Choosing a lens
Basic calculation example
The basic calculation on this page
does not take into consideration
DMD™ and image size, which
could affect the throw ratio.See Full
lens calculation on the facing page
for a more complex and realistic
calculation.
See Choosing a lens on page 112
for information about individual lens
part numbers.
INFORMATION YOU NEED FOR THIS CALCULATION
The throw ratio formula:
Allow a tolerance of +/- 3% in the throw ratio calculation.
The lens table:
Throw ratios
Focus range
0.377 : 1 fixed (UST) 0.82 m - 2.71 m
0.75 - 0.93 : 1 zoom
1.02 m - 12.7 m
0.76 : 1 fixed
0.81 m - 5.08 m
1.25 - 1.79 : 1 zoom
1.33 m - 11.73 m
1.73 - 2.27 : 1 zoom
1.83 m - 14.9 m
2.22 - 3.67 : 1 zoom
2.36 m - 24.2 m
3.58 - 5.38 : 1 zoom
3.8 m - 35.35 m
5.31 - 8.26 : 1 zoom
5.59 m - 54.8 m
1. Calculate the throw ratio using the formula.
Your screen is
4.5m
wide and you wish to place the projector approximately
11m
from the
screen. The throw ratio will then be
11 ÷ 4.5=
2.44
2. Match the result with the lens table.
The lens matching a throw ratio of 2.44 is the
2.22 - 3.67 : 1 zoom lens
.
3.
Check whether the lens covers the required throw distance.
The focus range quoted for the 2.22 - 3.67 : 1 zoom lens is
2.36 - 24.2m
.The required
distance of 11m is within the range.
Rev B April 2021
page 114
Reference Guide
Notes
