BenQ PB8250 Service Manual page 8

Note: L10, L11, L12, L13 are located at 10% of the distance from corner itself to L5
A2. ANSI UNIFORMITY
ANSI +Uniformity= Maximum (L1~13)-Average (L1~9)/ Average (L1~9)%
ANSI -Uniformity= Minimum (L1~13)-Average (L1~9)/ Average (L1~9)%
A3. JBMA UNIFORMITY
JBMA Uniformity = Average (L1,L3,L7,L9)/ L5
A4. ANSI CONTRAST
ANSI Contrast = Average lux value of the white rectangles/Average lux value of the black rectangles
Contrast Ratio shall be determined from illuminance values obtained from a
black-and-white "chessboard" pattern consisting of 16 equal rectangles. The white rectangles shall be
at 100% gray and the black rectangles at 0% gray. Illuminance measurements shall be made at the
center of each of the rectangles.
A5. FOFO CONTRAST
FOFO Contrast = Lux value at the center of a solid white screen/the lux value at the center of a solid
black screen
A6. JBMA CONTRAST
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