LAN Local Area Network:
connects different computers so that they can communicate with
each other. Different connection protocols are possible.
LD Laser diode:
is a type of light source which generates a single frequency in
the high end of the infrared spectrum and has a bandwidth of 1000 MHz.
It is used in fibre optics and infrared links.
Lead acid battery:
is a type of DC power source which is similar to a car battery.
It is generally used in temporary installations with DC cameras.
LED Light Emitting Device:
is a type of light source which generates an infrared frequency
when stimulated by electricity. It is used in fibre optics , infrared
links and as an infrared light source for monochrome cameras.
Lens calculator:
is a calculator provided by many lens manufacturers to help
calculate the focal length of the lens that will provide the required
scene.
Lens hunting:
is a field problem in which the iris opens and shuts
alternatively. A correct ALC adjustment in the lens could rectify the
problem.
Lens mount:
see C-mount or CS-mount.
Lens wheel:
see lens calculator.
Light:
is electromagnetic radiation between 400 nm and 750 nm which is
detectable by the human eye.
Light sensor:
is a device which is activated by a pre-set amount of light
falling on it. It can be used to switch infrared illuminators On / Off.
Limit switch:
is a device placed inside or outside the Pan Tilt head and used
to limit the angles of pan and tilt.
Line:
is the basic unit of a frame or field containing the charge
which is proportional to the light falling at various points on the
scanning line.
Looping switcher:
is a type of switcher with looping outputs. These outputs allow
the camera to be connected to another device without affecting the usage
of the switcher.
Lumen:
is a measurement of light which indicates the amount of light
radiated by a one candela light source.
Luminous flux:
is the rate of flow of light.
Luminance signal:
is that part of the video signal which contains the information
on the brightness of the picture.
Lux:
is an international unit of illumination. It is the amount of
uniform light falling on an area of 1 square meter and is measured in
lumen per sq. meter. |