BenQ PB8250 Service Manual page 9

JBMA Contrast = Average (L1,L2,L3,L4,L5,L6,L7,L8,L9) under solid white / Average
(L1,L2,L3,L4,L5,L6,L7,L8,L9) under solid black
A7. LIGHT LEAKAGE
Leakage = The maximum light leakage under a solid black pattern in or outside of the projected
image
A8. IMAGE DISTORTION
Keystone = (W2-W1)/ (W1+W2) x 100%
Vertical TV dist = (H1+H2-2xH3)/2H2 x100%
Horizontal TV dist = (W1+W2-2xW3)/2W1 x100%
W1: image width at image bottom
W2: image width at image top
W3: image width at the half image height.
H1: image height at image left
H2: image height at image right
H3: image height at half image
Note:
1. Keystone and Vertical TV Distortion are recommended for Front Projection Display
2. Vertical and Horizontal TV Distortion are recommended for Rear Projection Display
A9. THROW RATIO
Throw ratio = projection distance / the width of the projected image
A10. ZOOM RATIO
Zoom ratio = maximum / minimum image diagonal size at a fixed projection distance
A11. FOCUS RANGE
The minimum/maximum focus distance is the minimum/maximum projection distance (The
distance between the outermost element of projection lens and screen), expressed in meter, at which
the image is still at its acceptable focus level.(acceptable focus level is specified by FOCUS LIMIT
SAMPLE approved by customer)
A12. COLOR
Color is expressed as (x, y) in 1931CIE chromaticity values Note: Color is measured at the center of
the screen that is entirely the measured color under default brightness and contrast settings.
A13. ANSI COLOR
ANSI Color is expressed as (u, v) in 1976 CIE chromaticity values Note: Color is measured at the
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