Digital Projection Ltd. E-Vision Laser 13000 WU Series
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 94 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 A June 2019
page 96
Reference Guide
Notes
