Document #
Revision Date
82070-274, Revision A
18 of 20
1/16/2009
Glossary
Black Level:
This adjustment allows the display to be set to discriminate between small differences in dark
or near black areas of the image. The adjustment should make a black area of the image (such as a deep
shadow where all detail is lost in the image) appear black. The black level is decreased (less black) until a
change toward light or grey is perceived in this area, then the adjustment should be increased slightly to
restore the dark area to black. It is important to perform this adjustment on a truly black area in the image to
avoid making dark areas appear lighter than they actually are.
Brightness:
The intensity of light emitted from the LCD Display. This control is similar to the effect of
changing the light behind a stained glass window. As the illumination is increased the overall light output of
the image is increased. The proper adjustment takes into consideration the ambient light in the room. For a
brightly lit room, the brightness of the display may be increased to improve the visibility of the image. In a
dimly lit room, the brightness may be decreased to reduce the impact on the eye.
Clock:
This adjustment is seldom necessary, but if there is a problem with the frequency of the monitor
pixel clock that it cannot exactly match the clock signal from the camera (or other device), an adjustment
may be required. The symptom of a clock adjustment problem is the appearance of vertical bands in the
image. Adjustment of the clock will help eliminate these artifacts.
Color Temperature:
The measurement of color expressed in Kelvin (K). The reason this measurement is
called a "temperature" is because it was derived from a theoretical object called a "black body radiator."
When the radiator is heated, it changes from black to red to yellow to white to blue. The lower the Kelvin
rating, the "warmer" or more yellow the light. The higher the rating, the "cooler" or more blue the light.
Contrast:
Contrast is the differentiation between variations of similar colors. Typically contrast is set by
adjusting for best color differentiation between light yellow and white.
Gamma:
The way brightness is distributed across the intensity spectrum by a monitor, printer or scanner.
Depending on the device, the gamma may have a significant effect on the way colors are perceived.
Gamma is technically the relationship between the input voltage and resulting intensity of the output. A
perfect linear device would have a gamma of 1.0 and be plotted on a graph called a "tone curve" as a
straight line. Although a scanner is fairly linear, the tone curve of a monitor or printer is bent, yielding a
gamma in the range of 1.8 to 2.6, which effects midrange tones.
Hue:
Hue refers to the “shade” of the colors. Adjustment of this feature is applicable primarily to analog
signal sources. S-Video and VGA are analog signals. Adjustment of hue will help to correct abnormalities in
the signal. The adjustment can help in restoring the “natural” look of the colors.
Phase:
This adjustment is seldom necessary, but if there is a problem with the monitor pixel clock phase or
position in relation to the pixel clock generated by the camera (or other device), a phase adjustment may be
required. The symptom of phase problems is the appearance of horizontal lines flickering through the
image.
Saturation:
Saturation refers to the purity of any particular color component (Red, Green or Blue). For
example, 100% Red saturation is 100% Red, 0% Green and 0% Blue. No saturation means all the color
percentages are equal. Changes in saturation will change the emphasis of the selected color component.
