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.