Spreadsheet: 16aefa16-07b6-453a-95fc-8d0f2fb03946
Sheet: Sheet1

Unnamed: 0 | GAIN CALCULATOR FOR FRONT PROJECTION SCREENS | Unnamed: 2 | Unnamed: 3 | Unnamed: 4 | Unnamed: 5 | Unnamed: 6 | Unnamed: 7 | Unnamed: 8 | Unnamed: 9 | Unnamed: 10
DISCLAIMER:  This calculator is for entertainment only.  While the author believes the information and calculations contained herein are reasonably accurate,
you should not make a screen purchase decision based solely on the use of this calculator without further independent corroboration.
This calculator estimates screen gain at mid-screen height for the far-left edge, center, and far-right edge of the screen, according to the input values.
I used inches as my distance measurement unit initial values.  You may use a different distance unit (ft, cm), as long as you use the SAME unit throughout.
 |  | BASIC SETUP  (Change the green values as needed to fit your situation.)
What is the type of screen?  Specify A for angular reflective or R for retro reflective.  (Do not guess at this parameter--it makes a huge difference!) |  |  |  |  |  |  |  |  |  | R
What is the manufacturer-published on-axis centerscreen gain of your screen? |  |  |  |  |  |  |  |  |  | 2.4
What is the published maximum viewing angle (to one side in degrees off-axis)? |  |  |  |  |  |  |  |  |  | 20
What is the centerscreen gain at the published maximum viewing angle?  (Don't guess at this either.  Consult manufacturer if necessary) |  |  |  |  |  |  |  |  |  | 1.2
What is the minimum gain of your screen at large off-axis angles, e.g., 60 degrees?  (OK, you may guess here, but make it <= line 13 above.) |  |  |  |  |  |  |  |  |  | 0.51
What is the horizontal width of the viewing area of your screen? |  |  |  |  |  |  |  |  |  | 139
How high above the room floor is the center of your screen? |  |  |  |  |  |  |  |  |  | 51
How high above the room floor is the center of your projector's lens?
What is the distance from the front of the lens to the screen?  (Measure perpendicular to the screen.) |  |  |  |  |  |  |  |  |  | 252
How far back from the screen is the viewing position?  (Measure perpendicular to the screen.)
How far to the right or left of the screen center is the viewing position? (Use positive distance for right; negative distance for left.)
How high above the floor are the viewer's eyes when seated at the viewing position?
 |  | OPTIONAL SETUP   (You may not need to change these values.)
How far is your projector offset to the right or left of your screen center? (Enter positive distance for right; negative distance for left.)
Want instead to calculate the gain of screen points above or below mid-screen height?  Enter positive distance for above; negative distance for below.)
 |  |  |  |  |  |  |  |  | RETRO REFLECTIVE
Coordinate: | x | y | z |  |  |  |  | SCREEN | SCREEN | SCREEN
Screen Center Point: | 0 | 51 | 0 |  |  |  |  | LEFT | CENTER | RIGHT
Screen Right Point: | 69.5 | 51 | 0 |  |  |  | Calculated Error Angle (Degrees): | 71.11509889770419 | 78.55895613123258 | 71.11509889770419
Screen Left Point: | -69.5 | 51 | 0 |  |  |  | Estimated Screen Gain: | 0.5215592234545389 | 0.516372393260401 | 0.5215592234545389
PJ lens Point: | 0 | 0 | 252
Viewer Point: | 0 | 0 | 0
 |  |  |  | Vector Length
PJ Vector (Screen Center): | 0 | 51 | -252 | 257.1089263327899
PJ Vector (Screen Right): | 69.5 | 51 | -252 | 266.3367229654972
PJ Vector (Screen Left): | -69.5 | 51 | -252 | 266.3367229654972
Viewer Vector (Screen Center): | 0 | 51 | 0 | 51
Viewer Vector (Screen Right): | 69.5 | 51 | 0 | 86.20469824783333
Viewer Vector (Screen Left): | -69.5 | 51 | 0 | 86.20469824783333
PJ Unit Vector (Screen Center): | 0 | 0.1983595074952317 | -0.9801293311529093
PJ Unit Vector (Screen Right): | 0.2609478678950459 | 0.1914869246424078 | -0.9461706864683679
PJ Unit Vector (Screen Left): | -0.2609478678950459 | 0.1914869246424078 | -0.9461706864683679
Viewer Unit Vector (Screen Center): | 0 | 1 | 0
Viewer Unit Vector (Screen Right): | 0.8062205588863808 | 0.5916150863770564 | 0
Viewer Unit Vector (Screen Left): | -0.8062205588863808 | 0.5916150863770564 | 0
XY Factor for Angular/Retro: | 1
Best View UV (Screen Center): | 0 | 0.1983595074952317 | -0.9801293311529093
Best View UV (Screen Right): | 0.2609478678950459 | 0.1914869246424078 | -0.9461706864683679
Best View UV (Screen Left): | -0.2609478678950459 | 0.1914869246424078 | -0.9461706864683679
 | SCREEN | SCREEN | SCREEN
 | LEFT | CENTER | RIGHT
Viewer & Best View UV Dot Product: | 0.3236680893569484 | 0.1983595074952317 | 0.3236680893569484
Calculated Error Angle ([NAME]): | 71.11509889770419 | 78.55895613123258 | 71.11509889770419
Estimated Screen Gain: | 0.5215592234545389 | 0.516372393260401 | 0.5215592234545389