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Federal Communications Commission (US).
Fibre Distributed Data Interface.
Fast Fourier Transformation, see Fourier transformation.
Fibre optics. A technology
designed to transmit signals in the form of light. A Fibre Optic
system uses Optical Fibres. Optical
Fibre cable is noted
for its properties of electrical isolation
and resistance to
electrostatic and electromagnetic
Field. Refers to one-half
of the TV frame that is composed of either all odd or even lines.
CCIR systems each field is composed
of 625/2 = 312.5 lines (20ms), in EIA systems
525/2 = 262.5 lines (16.66ms).
There are 50 fields/second in CCIR/PAL, and 60 in the
EIA/NTSC TV system.
Fixed focal length lens.
A lens with a predetermined fixed focal length, a focusing
a choice of iris functions.
Flash memory. Nonvolatile,
digital storage. Flash memory has slower access than SRAM or
Flicker. An annoying
picture distortion, mainly related to vertical syncs and video fields
display. Some flicker normally
exists due to interlacing; more apparent in 50 Hz
(PAL). Flicker shows also
when static images are displayed on the screen such as
computer generated text transferred
to video. Poor digital image treatment,
low-quality system converters (going
from PAL to NTSC and vice versa), creates
annoying flicker on the screen.
There are several electronic methods
to minimize flicker.
The period where the scanning beam returns to the starting point for
In lenses with an adjustable iris, the maximum iris opening is
as a ratio
(focal length of the lens)/(maximum
effective diameter of aperture). This maximum
be marked on the front ring of
Focal length. The
distance between the optical centre of a lens and the principal
A means of adjusting the lens to allow objects at various distances
camera to be sharply defined.
An illumination light unit used mostly in American CCTV
equals 10.76 times the illumination
value in lux (1m2 = 10.76 sq ft).
Mathematical transformation of time domain functions into frequency
Frame. (See also Field).
Refers to a composition of lines that make one TV frame. In
CCIR/PAL TV system one frame is
composed of 625 lines (2 fields of 312.5 lines), while
in EIA/NTSC TV system 1 frame is
525 lines (2 fields of 262.5 lines). There are 25
frames/second in the CCIR/PAL and
30 frames /second in the
EIA/NTSC TV system.
Is mis-named. It is actually field integration and is the
adding sucessive fields together
to enhance an image in low light conditions. Integration
over more than a few fields will
cause motion blur to become an issue.
Frame store. An electronic
device that digitizes a TV frame (or TV field) of a video signal
and stores it in memory.
Multiplexers, fast scan transmitters, Quad displays
some of the latest colour cameras
have built-in frame stores.
Another name for a simple multiplexer, which can record multiple cameras
on a single VCR (and play back
any camera in full screen) but does not usually have
multiscreen image display.
Note : all cameras must be synchronized
Frame transfer (FT).
Refers to one of the principles of charge transfer in CCD chips.
The other two are interline and
Frame-interline transfer (FIT).
Refers to one of the principles of charge transfer in CCD
chips. It combines the principles
of both frame transfer and interline transfer to give the
benefits of both, without their
Frequency. The number
of complete cycles of a periodic waveform that occur in a one
second period. Usually specified
in Hertz (formerly cycles per second).
Frequency modulation (FM).
The modulation of a carrier wave by varying its frequency in
accordance with amplitude variations
of the modulating signal.
Front porch. The blanking
signal portion that lies between the end of the active line period
and the leading edge of line sync
(horizontal sync), 1.5µs long in a CCIR/PAL system.