NEC Display Solutions of America, Inc.
NP901W Installation Guide
Ceiling Mounted and Desktop
Rev 1.0
www.necdisplay.com
NP901W
Page 2 of 6
Formulas
The Projection Formulas use the image width for calculation. Image height is the same for all aspect ratios, only horizontal image
size varies when using a 16:10 aspect ratio screen. For proper projector placement, determine the image width for a desired screen
size. Use the Screen Formulas below to calculate all screen dimensions. Plug in the image width “W” for a 16:10 aspect ratio image
in the Projection Formulas.
Refer to the diagrams (page 5) and charts below for popular screen sizes 16:10 screens:
Definitions:
16:10 Screen Formulas:
W
=
Image
Width
W
=
H
x
16/10
H
=
Image
Height
(size)
H
=
W
x
10/16
B = Vertical distance between lens center and screen center
Screen Diagonal = W x 18.868/16
C = Throw distance
D = Vertical distance between lens center and screen top
(screen
bottom
for
desktop
application)
Projection Formulas:
B
=
0.271W
C
(wide) = 1.4477W – 1.823
C
(tele) = 1.7386W – 1.820
D
= -0.040W
α
(wide) = tan¯¹ (B/C(wide))
α
(tele) = tan¯¹ (B/C(tele))
Note:
Tilting the front of the projector or down by more than 45° from level could reduce lamp life by up to 20%.
Distance Chart for popular 16:10 screens
Diagonal Width(W) Height (H)
inches
inches
inches
inches
85
72
45
20
102
-
123
10.8 -
9.0
92
78
49
21
112
-
134
10.8 -
9.0
98
83
52
23
119
-
143
10.8 -
9.0
102
86
54
23
123
-
148
10.7 -
9.0
111
94
59
25
134
-
162
10.7 -
9.0
113
96
60
26
137
-
165
10.7 -
9.0
123
104
65
28
149
-
179
10.7 -
9.0
125
106
66
29
151
-
182
10.7 -
9.0
147
125
78
34
179
-
215
10.7 -
9.0
149
126
79
34
181
-
218
10.7 -
8.9
213
181
113
49
260
-
313
10.7 -
8.9
255
216
135
59
311
-
374
10.7 -
8.9
-5
-5
-7
-9
-4
-4
-4
-4
-3
-3
-3
-3
inches
inches
inches
Image Size (16:10)
on a (16:10) screen
B
C
w ide - tele
D
α
w ide - tele
Note:
For screen sizes not indicated on the projection tables, use the formulas on page above.
