NEC NP901W - Page 2

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
i
nc
h
es
i
nc
h
es
i
nc
h
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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.