NEC NP-VE281 Installation Manual page 2

VE281/VE281X/VE282B/VE282XB Installation Guide
Ceiling and Desktop Mounted
Formulas
The Projection Formulas use the image width for calculation. For proper projection placement, determine the image width
for the desired screen size. Use the Screen Formulas below to calculate all screen dimensions. Plug in the width for "W" in
the Projection Formulas.
Refer to the diagrams and charts below for popular screen sizes:
Definitions:
W = Image Width
H = Image Height (size)
B = Vertical distance between lens center and screen center
C = Throw distance
D = Vertical distance between lens center and screen top
(screen bottom for desktop application)
Projection Formulas:
B = 0.487W
C (wide) = 1.94W
C (tele) = 2.165W
D = 0.112W
α (wide) = tan¯¹ (B/C(wide))
α (tele) = tan¯¹ (B/C(tele))
Distance Chart for popular 4:3 screens
Screen Size (4:3)
Diagonal Width(W) Height (H)
inches inches
30 24
60 48
67 53.6
72 57.6
84 67.2
.
90 72
100 80
120 96
150 120
180 144
210 168
240 192
270 216
300 240
Note:
For screen sizes not indicated on the projection tables, use the formulas on above
www.necdisplay.com
B
inches inches
18 12
36 23
40.2 26
43.2 28
50.4 33
54 35
60 39
72 47
90 58
108 70
126 82
144 94
162 105
180 117
NEC Display Solutions of America, Inc.
4:3 Screen Formulas:
W = H x 4/3
H = W x 3/4
Screen Diagonal = W x 5/4
C
w ide - tele
inches
46 - 52
93 - 104
104 - 116
111 - 125
130 - 146
139 - 156
155 - 173
186 - 208
232 - 260
279 - 312
325 - 364
372 - 416
418 - 468
465 - 520
VE281/VE281X/VE282B/VE282XB
D
α
w ide - tele
inches degrees
3
14.1 -
5
14.1 -
6
14.1 -
6
14.1 -
8
14.1 -
8
14.1 -
9
14.1 -
11
14.1 -
13
14.1 -
16
14.1 -
19
14.1 -
22
14.1 -
24
14.1 -
27
14.1 -
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