Magnification
ratio:
is the ratio between the focal
length of a lens and the focal length of
a standard angle lens. It indicates the
magnification of the image on the monitor
as compared to the image seen by a standard
angle lens. Matrix
switcher:
is a type of switcher which allows
a single input to be switched to many
outputs. Matrix switchers are used in
large CCTV systems and have many powerful
features.
Mercury
vapour lamp:
is a popular type of artificial
light source which emits a blue-white
light. Used extensive for commercial lighting.
Micron:
is a unit of measuring length.
1 micron = 10 -6 meters
Microwave
detector:
is a type of alarm which uses
microwaves to detect movement in a zone.
Microwave
link:
is a type of transmission medium
in which video, data or audio is modulated
with a microwave frequency and then transmitted
to a receiver in a remote location.
Mimic
panel:
is a panel which shows the layout
of a site with the camera positions highlighted.
By interfacing it with a switcher, the
operator can switch any camera to the
monitors from the mimic panel itself.
Minimum
scene illumination:
is a specification shown in most
camera data sheets and indicates the minimum
light required at the scene to provide
a reasonable picture on the monitor.
Modem:
is derived from the term 'modulator
-demodulator' and is used to convert
a digital signal into an analogue signal
so that it can be transmitted via the
PSTN telephone network.
Modulate:
is a method in which a signal
to be transmitted is mixed with a high
frequency carrier signal .
Motorised
iris:
is a type of iris control in
which the iris motor is controlled from
a remote location.
Multi
core cable:
is a type of cable which has
many cores enclosed in one outer jacket.
In CCTV it is normally used to transmit
control signals.
Multimode
cable:
is a cheaper type of fibre optics
cable which allows a light beam to travel
by more than one path thus causing transmission
distortion.
Multiplexing:
is a process whereby many cameras
are switched frame by frame. This frame
switching can be used in applications
like multiviewing, multirecording etc.
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