B&K Precision 1253 - Manual - Manual (Page 19)

11: ANSI Gray
Description: Pattern is an all white raster with two centered three-step gray scales. The top gray scale
steps are at 10%, 5%, and 0% white levels. The bottom gray scale steps are at 90%, 95%, and 100% white
levels (from left to right).
Pattern Usage: This pattern can be used to check a display device’s ability to hold proper black level at
close to 100% APL. Check that you can see three separate levels of dark gray and black in the top gray
scale. The pattern is primarily useful, however, in checking for peak-white clipping in fixed-panel
projectors (LCD, DLP, and D-ILA). In these devices, the projector bulb determines the maximum amount
of light output. If the contrast control is adjusted too high, not only the 100 IRE white levels, but also
lower IRE signal levels will produce the same maximum light output level. This will result in peak white
clipping, with loss of high-brightness picture detail. Check that you can see three separate levels of bright
gray and white in the bottom gray scale. If the brighter levels blend together, reduce the contrast control
below the level of clipping.
Examples of Uncalibrated Displays: The following images indicate a TV with the Brightness and/or
Contrast levels not set properly. Keep in mind, most monitors can not handle this pattern, so reserve this
pattern for calibrating only high end TV's and monitors.
Too Dark
Too Bright Smearing
Same Brightness Level
Same Brightness Level
(Peak-White Clipping)