Pattern 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% while levels. The bottom gray scale steps are at 90%, 95%, and 100% while 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.
Multiburst
Pattern Description: Pattern consists of five equal-width vertical segments. Vertical segments are filled with alternating black and white stripes of one, two, three, four, and five pixel spacing (right to left). This pixel spacing directly corresponds to the horizontal resolution of the format being displayed. If, for example, the horizontal resolution of the current format is 640, the one pixel spacing is such that, if it were continued across the entire screen, there would be 320 white and 320 black stripes.
The exception to this is the 720 and 1080 HD formats, for which the 1920 pixel resolution, if repeated across the screen, would result in a video signal frequency of 37 MHz, which exceeds the SMPTE and EIA-specified format bandwidth of 30 MHz. In these formats, the stripes are at two, four, six, eight, and ten pixel spacing.
Pattern Usage: Use to check a display device’s capability to produce sharply defined stripes, at equal brightness, up to the format’s full resolution. This pattern is also useful in adjusting the sharpness control. Starting with the sharpness control at its minimum setting, increase the control until all five bursts are at equal brightness levels. Do not adjust the control high enough to cause ghosting lines adjacent to the widest stripes.
