NEC NP901W - Page 4

NEC Display Solutions of America, Inc.
NP901W Installation Guide
Ceiling Mounted and Desktop Rev 1.0
www.necdisplay.com NP901W Page 4 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 4:3 aspect ratio image in
the Projection Formulas.
Refer to the diagrams (page 5) and charts below for popular screen sizes 16:9 screens:
Definitions: 4:3 Screen Formulas:
W = Image Width W = H x 4/3
H = Image Height (size) H = W x 3/4
B = Vertical distance between lens center and screen center Screen Diagonal = W x 5/4
C = Throw distance
D = Vertical distance between lens center and screen top
(screen bottom for desktop application)
Projection Formulas:
B = 0.327W
C(wide) = 1.737W – 1.823
C(tele) =2.085W – 1.820
D = -0.050W
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 4:3 aspect ratios on a 16:9 screen
Diagonal Width(W) Height (H) Diagonal Width(W) Height (H)
inches inches inches inches inches inches inches
49 43 24 40 32 24 10 54 - 65 10.8 - 9.0
73 64 36 60 48 36 16 81 - 98 10.8 - 9.0
92 80 45 75 60 45 20 102 - 123 10.8 - 9.0
100 87 49 82 65 49 21 112 - 134 10.8 - 9.0
106 92 52 87 69 52 23 118 - 143 10.8 - 9.0
110 96 54 90 72 54 24 123 - 148 10.7 - 9.0
120 105 59 98 78 59 26 134 - 161 10.7 - 9.0
122 107 60 100 80 60 26 137 - 165 10.7 - 8.9
133 116 65 108 87 65 28 149 - 179 10.7 - 8.9
135 117 66 110 88 66 29 151 - 181 10.7 - 8.9
159 139 78 130 104 78 34 179 - 215 10.7 - 8.9
161 140 79 132 105 79 34 181 - 218 10.7 - 8.9
230 201 113 188 151 113 49 260 - 312 10.7 - 8.9
275 240 135 225 180 135 59 310 - 373 10.7 - 8.9
Screen Size (16:9)
Image Size (4:3)
on a (16:9) screen
B
inchesinches inches
C
w ide - tele
D
α
w ide - tele
-2
-2
-3
-3
-3
-4
-4
-4
-9
-4
-4
-5
-8
-5
Note:
For screen sizes not indicated on the projection tables, use the formulas on page above.
Input Signal Aspect Ratio 4:3 image on a 16:9 screen