Extron • System 8/10 P
LUS
• User’s Manual
Reference
B-15
Glossary of Terms
Brightness – Usually refers to the amount, or intensity of video light produced on a screen.
Sometimes called “black level”.
Buffer – Generally referred to as a unity gain amplifier used to isolate the signal source
from the load. This is for both digital and analog signals.
C– In S-Video, “C” is an abbreviation for Chrominance, or the color information. (“Y”
is for Luminance, or the brightness.)
Cable Equalization – The method of altering the frequency response of a video amplifier to
compensate for high frequency losses in cables that it feeds. (See Peaking.)
Capacitance – The storing of an electrical charge. At high frequencies, capacitance that exists
in cables also represents a form of impedance.
Chroma – The characteristics of color information, independent of luminance intensity. Hue
and saturation are qualities of chroma. Black, gray, and white objects do not
have chroma characteristics.
Chrominance Signal – Part of a television signal containing the color information. Abbreviated by “C”.
Coaxial Cable – A two-conductor wire in which one conductor completely wraps the other with the
two separated by insulation. Constant impedance transmission cable.
Color – An Extron adjustment that is used to control color intensity.
Component Video – Our color television system starts with three channels of information; Red,
Green, & Blue (RGB). In the process of translating these channels to a single
composite video signal they are often first converted to Y, R-Y, and B-Y. Both 3-
channel systems, RGB and Y, R -Y, B -Y are component video signals. They are
the components that eventually make up the composite video signal. Much
higher program production quality is possible if the elements are assembled in
the component domain.
Composite Sync – A signal combining horizontal and vertical sync pulses, and equalizing pulses,
with no picture information. Sometimes called ”C”, “S” (as in RGBS) or “HV”.
Composite Video – An all-in-one video signal comprised of the luminance (black and white),
chrominance (color), blanking pulses, sync pulses and color burst.
Contrast – The range of light and dark values in a picture, or the ratio between the
maximum and the minimum brightness values. Low contrast is shown mainly as
shades of gray, while high contrast is shown as blacks and whites with very little
gray. It is also a TV monitor adjustment which increases or decreases the level
of contrast of a displayed picture. Also called “white level”.
Crosstalk – Interference, usually from an adjacent channel, which adds an undesirable signal
to the desired signal.
Crosstalk Isolation – Attenuation of an undesired signal introduced by crosstalk.
CRT (Cathode Ray Tube) – A vacuum tube that produces light on a screen when energized by the electron
beam from inside the tube. A CRT has a heater element, cathode, and grids in
the neck of the tube, making up the “gun”. An electron beam is produced by the
gun and is accelerated toward the screen surface of the tube. The screen’s
inside surface is coated with phosphors that light up when hit by the electron
beam. The CRT is more commonly known as the picture tube. Some color CRTs
have three guns – for red, green and blue colors.
DAT (Digital Audio Tape) – A method developed by Sony and Hewlett-Packard for recording large amounts
of information in digital form on a small cassette tape. It uses a rotating helical
read/write head, similar to the technique used on a VCR.
dB (Decibel) – The standard unit used to express gain or loss of power. It indicates the
logarithmic ratio of output power divided by input power. A power loss of 3 dB is
an attenuation of half of the original value. The term “3dB down” is used to
describe the “half power point”.
im Vertrieb von
CAMBOARD Electronics
www.camboard.de
Tel. 07131 911201
Fax 07131 911203
