Quantum Data 801GC - Manual (Page 52)

4-14 Chapter 4: Built-In Images Model 801GC, 801GF & 801GX¥Rev. X1
CheckBy3
Description The active video area is equally divided into a
three by three checkerboard of black and white
boxes. The primary version has four white boxes
as shown in the figure on the left. The secondary
version has five white boxes as shown in the figure
on the right.
Test Contrast ratio
Purpose The pattern is based on a proposed ANSI method
of measuring the contrast ratio of video projection
systems.
Method Using a suitable light meter probe, measure and
record the light-level reading (in foot lamberts)
in the center of each of the black and white boxes.
The contrast ratio is expressed as the average of
all of the white readings divided by the average
of all of the black readings.