Quantum Data 881 - Manual (Page 1205)

881/882 Video Test Generator User Guide (Rev A.22) 1089
Test High contrast resolution
Method All the 0 and 100% level stripes in all the resolution patches should be separate and
distinct.
Test Low contrast resolution and noise
Method All the mid-level 2 on - 2 off stripes in all the resolution patches should be visible and
distinct. This is a sensitive test for noise in the display’s video amplifiers.
Test Quick gamma check
Method The average brightness level of the small gamma dither box should match the brightness
of the larger surrounding box. This is a visual check to see if the display’s gamma
correction is producing the correct mid-level response.
Test Video gain linearity and gamma
Method The individual grayscale boxes all should be at their indicated levels. A small aperture
photometer is usually required to get accurate and repeatable readings.
Test Contrast and brightness check
Method On a display with properly adjusted brightness and contrast controls, both the 5% and
95% contrast boxes should be clearly visible inside their larger surrounding 0% and 100%
boxes.
Test Video amplifier stability
Method The two black-and-white windows should show sharp transitions between the smaller box
and the surrounding window. Streaking may be an indication of undershoot or overshoot
while ghost images may indicate a ringing problem.
Test Excessive overscan and off-center alignment
Method The entire border should be clearly visible on the face of the tube and not be hidden by the
edge of the glass or by any bezel.
Test Interlace flicker