Back
focus:
is a fine mechanical adjustment in the camera
which moves the CCD chip or the lens mount
(depending upon camera brand) to ensure
the chip is placed at the exact focal point
of the lens. Backlash:
is an error present in a pan tilt head
due to the play in the mechanical components
like gears, pulleys etc. This results
in the Pan Tilt head not stopping instantaneously.
This error is critical in pre set PTZ
cameras and is measured in degrees.
Balanced
cable:
is a type of cable in which the signal
is divided over a pair of cables and travels
in opposing polarity. This reduces interference
allowing transmission over longer distances.
Bandwidth:
is the range of frequencies that pass
through an electrical/electronic amplifying,
processing or transmission unit without
attenuation or loss.
Barrel
distortion:
is a distortion in the monitor due to
non uniform scanning which causes the
image to bulge outwards like a barrel.
Beam
angle:
is the angular beam width of a conical
beam of light and is measured in degrees.
Blanking
pulse:
is a black pulse added during the fly
back period to make the video signal invisible
on the screen.
BNC
connector:
is a type of connector used to interconnect
two coaxial cables or connect a cable
with other CCTV components.
Bridging
switcher:
is a type of sequential switcher which
has two outputs. The sequencing output
sequences all the camera inputs whereas
the other output is a spot output where
any camera can be called up for extended
viewing.
Brightness:
represents the intensity of illumination
of the reproduced picture.
Brightness
Control:
is a control in the monitor which does
not change the amplitude of the video
signal but increases or decreases the
illumination of the phosphors on the screen.
Broadcast
camera:
is a high quality camera using three CCD
chips. It is used extensively in the professional
broadcasting industry. |
